dustoff17
Still trying to reach the Top Shelf
OK then, here were you when JFK was shot?
And don’t say you weren’t born yet, don’t confuse this investigation with facts!
737 goes down off Hawaii
- Thread starter GypsyPilot
- Start date
And don’t say you weren’t born yet, don’t confuse this investigation with facts!
ppragman
FLIPY FLAPS!
Dammit, alright, it was me. I shot JFK. Decades before my birth I • him from the building next to the book repository.
Wardogg
Meat Popsicle
- NTSB issues the final report into an accident involving Transair flight 810, a Boeing 737-275C Adv. cargo plane, N810TA, that occurred on July 2, 2021, off Honolulu, Hawaii:
On July 2, 2021, about 0145 Hawaii-Aleutian standard time, Rhoades Aviation flight 810, dba Transair flight 810, a Boeing 737-200, N810TA, experienced an engine anomaly shortly after takeoff from Daniel K. Inouye International Airport (HNL), Honolulu, Hawaii, and was subsequently ditched into Mamala Bay (in the Pacific Ocean), about 5.5 miles southwest of HNL. The captain sustained serious injuries, the first officer sustained minor injuries, and the airplane was destroyed. The flight was operating under Title 14 Code of Federal Regulations Part 121 as a cargo flight from HNL to Kahului International Airport (OGG), Kahului, Hawaii.
Transair flight 810, a Title 14 Code of Federal Regulations Part 121 cargo flight, experienced a partial loss of power involving the right engine shortly after takeoff and a water ditching in the Pacific Ocean about 11.5 minutes later. This analysis summarizes the accident and evaluates (1) the right engine partial loss of power, (2) the captain's communications with air traffic control (ATC) and the first officer's left and right engine thrust reductions, (3) the first officer's misidentification of the affected engine and the captain's failure to verify the information, (4) checklist performance, and (5) survival factors. Maintenance was not a factor in this accident.
The flight data recorder (FDR) showed that, when the initial thrust was set for takeoff, the engine pressure ratios (EPR) for the left and right engines were 2.00 and 1.97, respectively. Shortly after rotation, the cockpit voice recorder (CVR) recorded a “thud” and the sound of a low-frequency vibration. The captain (the pilot monitoring at the time) and the first officer (the pilot flying) reported that they heard a “whoosh” and a “pop,” respectively, at that time. As the airplane climbed through an altitude of about 390 ft while at an airspeed of 155 knots, the right EPR decreased to 1.43 during a 2-second period. The airplane then yawed to the right; the first officer countered the yaw with appropriate left rudder pedal inputs. The CVR showed that the captain and the first officer correctly determined that the No. 2 (right) engine had lost thrust within 5 seconds of hearing the thud sound.
After moving the flaps to the UP position, the captain reduced thrust to maximum continuous thrust, causing the left EPR to decrease from 1.96 to 1.91 while the airplane was in a climb. (The right EPR remained at 1.43). The captain reported that he did not move the thrust levers again until after he became the pilot flying. The first officer stated that, after the airplane leveled off at an altitude of about 2,000 ft, he reduced thrust on both engines. FDR data showed that thrust was incrementally reduced to near flight idle (1.05 EPR on the left engine and then 1.09 EPR on the right engine) and that airspeed decreased from about 250 to 210 knots. (A decrease in airspeed to 210 knots was consistent with the operator’s simulator guide procedures for a single-engine failure after the takeoff decision speed [V1]. The simulator guide, which supplemented information in the company’s flight crew training manual, contained the most recent operator guidance for single-engine failure training at the time of the accident.)
The captain was unaware of the first officer’s thrust changes because he was busy contacting the controller about the emergency. The captain told the controller, “we’ve lost an engine,” but he had declared the emergency to the controller twice before this point, as discussed later in this analysis.
The captain instructed the first officer to maintain a target speed of 220 knots (which the captain thought would be “easy on the running engine”), a target altitude of 2,000 ft, and a target heading of 240°. (About 52 seconds earlier, the controller had issued the 240° heading instruction to another airplane on the same radio frequency.) About 3 minutes 14 seconds after the right engine loss of thrust occurred, the captain assumed control of the airplane; at that time, the airplane’s airspeed was 224 knots and heading was 242°, but the airplane’s altitude had decreased from about 2,100 ft (the maximum altitude that the airplane reached during the flight) to 1,690 ft. The captain increased the airplane’s pitch to 9°; the airplane’s altitude then increased to 1,878 ft, but the airspeed decreased to 196 knots.
The captain subsequently stated, “let’s see what is the problem...which one...what's going on with the gauges,” and “who has the E-G-T [exhaust gas temperature]?” The first officer stated that the left engine was “gone” and “so we have number two” (the right engine), thus misidentifying the affected engine. The captain accepted the first officer’s assessment and did not take action to verify the information. Afterward, the EPR level on the right engine began to increase in response to the captain advancing the right thrust lever so that the airplane could maintain airspeed and altitude. Right EPR increased and decreased several times during the rest of the flight (coinciding with crew comments regarding the EGT on the right engine and low airspeed) while the left EPR remained near flight idle.
The first officer asked the captain if they “should head back toward the airport” before the airplane traveled “too far away,” and the captain responded that the airplane would stay within 15 miles of the airport. During a postaccident interview, the captain stated that, because there was no fire and an engine “was running,” he intended to have the airplane climb to 2,000 ft and stay within 15 miles of the airport to avoid traffic and have time to address the engine issue. The captain also stated that he had been criticized by the company chief pilot for returning to the airport without completing the required abnormal checklist for a previous in-flight emergency. Although the captain’s decision resulted in the accident airplane flying farther away from the airport and farther over the ocean at night, the captain’s decision was reasonable for a single-engine failure event.
The captain directed the first officer to begin the Engine Failure or Shutdown checklist and stated that he would continue handling the radios. The first officer began to read aloud the conditions for executing the Engine Failure or Shutdown checklist but then stopped to tell the captain that the right EGT was at the “red line” and that thrust should be reduced on the right engine. The captain then decided that the airplane should return to the airport and contacted the controller to request vectors.
The flight crew continued to express concern about the right engine. The first officer stated, “just have to watch this though…the number two.” The captain asked the first officer to check the EGT for the right engine, and the first officer responded that it was “beyond max.” Afterward, the captain told the first officer to continue with the Engine Failure or Shutdown checklist and finish as much as possible. The first officer resumed reading aloud the conditions for performing the checklist but then stopped to state, “we have to fly the airplane though,” because the airplane was continuing to lose altitude and airspeed. The captain replied “okay.” As a result, the flight crew did not perform key steps of the checklist, including identifying, confirming, and shutting down the affected (right) engine.
The first officer told the captain that the airplane was losing altitude; at that time, the airplane’s altitude was 592 ft, and its airspeed was 160 knots. The captain agreed to select flaps 1 (which the first officer had previously suggested likely because the airplane was slowing). The CVR then recorded the first enhanced ground proximity warning system (EGPWS) annunciation (500 ft above ground level); various EGPWS callouts and alerts continued to be annunciated through the remainder of the flight. The captain then told the controller that “we’ve lost number one
On July 2, 2021, about 0145 Hawaii-Aleutian standard time, Rhoades Aviation flight 810, dba Transair flight 810, a Boeing 737-200, N810TA, experienced an engine anomaly shortly after takeoff from Daniel K. Inouye International Airport (HNL), Honolulu, Hawaii, and was subsequently ditched into Mamala Bay (in the Pacific Ocean), about 5.5 miles southwest of HNL. The captain sustained serious injuries, the first officer sustained minor injuries, and the airplane was destroyed. The flight was operating under Title 14 Code of Federal Regulations Part 121 as a cargo flight from HNL to Kahului International Airport (OGG), Kahului, Hawaii.
Transair flight 810, a Title 14 Code of Federal Regulations Part 121 cargo flight, experienced a partial loss of power involving the right engine shortly after takeoff and a water ditching in the Pacific Ocean about 11.5 minutes later. This analysis summarizes the accident and evaluates (1) the right engine partial loss of power, (2) the captain's communications with air traffic control (ATC) and the first officer's left and right engine thrust reductions, (3) the first officer's misidentification of the affected engine and the captain's failure to verify the information, (4) checklist performance, and (5) survival factors. Maintenance was not a factor in this accident.
The flight data recorder (FDR) showed that, when the initial thrust was set for takeoff, the engine pressure ratios (EPR) for the left and right engines were 2.00 and 1.97, respectively. Shortly after rotation, the cockpit voice recorder (CVR) recorded a “thud” and the sound of a low-frequency vibration. The captain (the pilot monitoring at the time) and the first officer (the pilot flying) reported that they heard a “whoosh” and a “pop,” respectively, at that time. As the airplane climbed through an altitude of about 390 ft while at an airspeed of 155 knots, the right EPR decreased to 1.43 during a 2-second period. The airplane then yawed to the right; the first officer countered the yaw with appropriate left rudder pedal inputs. The CVR showed that the captain and the first officer correctly determined that the No. 2 (right) engine had lost thrust within 5 seconds of hearing the thud sound.
After moving the flaps to the UP position, the captain reduced thrust to maximum continuous thrust, causing the left EPR to decrease from 1.96 to 1.91 while the airplane was in a climb. (The right EPR remained at 1.43). The captain reported that he did not move the thrust levers again until after he became the pilot flying. The first officer stated that, after the airplane leveled off at an altitude of about 2,000 ft, he reduced thrust on both engines. FDR data showed that thrust was incrementally reduced to near flight idle (1.05 EPR on the left engine and then 1.09 EPR on the right engine) and that airspeed decreased from about 250 to 210 knots. (A decrease in airspeed to 210 knots was consistent with the operator’s simulator guide procedures for a single-engine failure after the takeoff decision speed [V1]. The simulator guide, which supplemented information in the company’s flight crew training manual, contained the most recent operator guidance for single-engine failure training at the time of the accident.)
The captain was unaware of the first officer’s thrust changes because he was busy contacting the controller about the emergency. The captain told the controller, “we’ve lost an engine,” but he had declared the emergency to the controller twice before this point, as discussed later in this analysis.
The captain instructed the first officer to maintain a target speed of 220 knots (which the captain thought would be “easy on the running engine”), a target altitude of 2,000 ft, and a target heading of 240°. (About 52 seconds earlier, the controller had issued the 240° heading instruction to another airplane on the same radio frequency.) About 3 minutes 14 seconds after the right engine loss of thrust occurred, the captain assumed control of the airplane; at that time, the airplane’s airspeed was 224 knots and heading was 242°, but the airplane’s altitude had decreased from about 2,100 ft (the maximum altitude that the airplane reached during the flight) to 1,690 ft. The captain increased the airplane’s pitch to 9°; the airplane’s altitude then increased to 1,878 ft, but the airspeed decreased to 196 knots.
The captain subsequently stated, “let’s see what is the problem...which one...what's going on with the gauges,” and “who has the E-G-T [exhaust gas temperature]?” The first officer stated that the left engine was “gone” and “so we have number two” (the right engine), thus misidentifying the affected engine. The captain accepted the first officer’s assessment and did not take action to verify the information. Afterward, the EPR level on the right engine began to increase in response to the captain advancing the right thrust lever so that the airplane could maintain airspeed and altitude. Right EPR increased and decreased several times during the rest of the flight (coinciding with crew comments regarding the EGT on the right engine and low airspeed) while the left EPR remained near flight idle.
The first officer asked the captain if they “should head back toward the airport” before the airplane traveled “too far away,” and the captain responded that the airplane would stay within 15 miles of the airport. During a postaccident interview, the captain stated that, because there was no fire and an engine “was running,” he intended to have the airplane climb to 2,000 ft and stay within 15 miles of the airport to avoid traffic and have time to address the engine issue. The captain also stated that he had been criticized by the company chief pilot for returning to the airport without completing the required abnormal checklist for a previous in-flight emergency. Although the captain’s decision resulted in the accident airplane flying farther away from the airport and farther over the ocean at night, the captain’s decision was reasonable for a single-engine failure event.
The captain directed the first officer to begin the Engine Failure or Shutdown checklist and stated that he would continue handling the radios. The first officer began to read aloud the conditions for executing the Engine Failure or Shutdown checklist but then stopped to tell the captain that the right EGT was at the “red line” and that thrust should be reduced on the right engine. The captain then decided that the airplane should return to the airport and contacted the controller to request vectors.
The flight crew continued to express concern about the right engine. The first officer stated, “just have to watch this though…the number two.” The captain asked the first officer to check the EGT for the right engine, and the first officer responded that it was “beyond max.” Afterward, the captain told the first officer to continue with the Engine Failure or Shutdown checklist and finish as much as possible. The first officer resumed reading aloud the conditions for performing the checklist but then stopped to state, “we have to fly the airplane though,” because the airplane was continuing to lose altitude and airspeed. The captain replied “okay.” As a result, the flight crew did not perform key steps of the checklist, including identifying, confirming, and shutting down the affected (right) engine.
The first officer told the captain that the airplane was losing altitude; at that time, the airplane’s altitude was 592 ft, and its airspeed was 160 knots. The captain agreed to select flaps 1 (which the first officer had previously suggested likely because the airplane was slowing). The CVR then recorded the first enhanced ground proximity warning system (EGPWS) annunciation (500 ft above ground level); various EGPWS callouts and alerts continued to be annunciated through the remainder of the flight. The captain then told the controller that “we’ve lost number one
engine…there’s a chance we’re gonna lose the other engine too it’s running very hot….we’re pretty low on the speed it doesn't look good out here.” Also, the captain mentioned that the controller should notify the US Coast Guard (USCG) because he was anticipating a water ditching in the Pacific Ocean.
Because of the high temperature readings on the right engine, the flight crew thought, at this point in the flight, that a dual-engine failure was imminent. During a postaccident interview, the captain stated that his priority at that time was figuring out how the airplane could stay in the air and return safely to the airport. The captain also stated that he attempted to resolve the airplane’s deteriorating energy state by advancing the right engine thrust lever. However, with the left engine remaining near flight idle, the right engine was not producing sufficient thrust to enable the airplane to maintain altitude or climb.
The captain’s communication with the controller continued, and the first officer stated, “fly the airplane please.” The controller asked if the airport was in sight, and the captain then asked the first officer whether he could see the airport. The first officer responded “pull up we’re low” to the captain and “negative” to the controller; the captain was likely unable to respond to the controller because he was trying to control the airplane.
The captain asked the first officer about the EGT for the right engine; the first officer replied “hot…way over.” The captain then asked about, and the controller responded by providing, the location of the closest airport. Afterward, the CVR recorded a sound similar to the stick shaker, which continued intermittently through the rest of the flight. The CVR then recorded sounds consistent with water impact.
The aircraft performance study for this accident found that the airplane had adequate total engine thrust available to climb, accelerate, and maintain altitude both before and after the rapid decrease in right EPR to 1.43. However, as the left EPR decreased and remained below a level of 1.2 (which occurred about 35 seconds after the airplane leveled off at 2,000 ft and while the EPR on the right engine was about 1.4), total engine thrust decreased to the point that the airplane transitioned to and remained at a low-energy state (that is, low total engine thrust, low airspeed, and low altitude). The flight crew relied exclusively on thrust from the damaged right engine as thrust on the left engine remained near flight idle. With this engine power configuration, the flight crew could not arrest the airplane’s descent, and the airplane was unable to maintain altitude, accelerate, or climb because the flight crew did not take the corrective action of adding left engine thrust, which was available.
Right Engine Loss of Thrust and Left Engine Pressure Ratio Decrease
The rotational signatures observed during postaccident examination of both engines indicated that the right engine was rotating at a much faster speed at impact than the left engine. The indications showing low rotation of the left engine core at impact were consistent with the engine operating near flight idle at that time. Postaccident examination of the left engine found no anomalies that would have caused the reduced thrust on that engine.
The teardown of the right engine showed that two high-pressure turbine stage 1 blades were missing their outer spans and that both had failed from a stress rupture fracture due to oxidation and corrosion of the internal blade lightening (weight-reduction) holes, which resulted in a loss of load-bearing cross-section. The blade failures caused downstream (secondary) damage to the low-pressure turbine, resulting in a loss of thrust, which would have been presented to the flight crew as a decrease in EPR on the right engine (along with the thud sound recorded on the CVR and the yaw to the right).
Postaccident examination of the high-pressure turbine stage 1 right engine blades also revealed that they had been exposed to temperatures beyond the blades’ normal operating range, resulting in microstructure changes to the blade material. According to flight crew postaccident interviews as well as CVR evidence, the right EGT was at the top of the gauge (at or above the red line). Also, the operator’s Boeing 737 Aircraft Operations Manual stated that the maximum continuous EGT for the airplane’s engines was 540°C, but the EGT gauge was found in the wreckage indicating 700°C. Thus, the overtemperature damage on the right engine blades likely occurred during the accident flight when the engine was operated at elevated temperatures.
Notification to Controller About Emergency and Engine Thrust Reductions
The captain first declared an emergency to the controller about 36 seconds after the CVR recorded the thud sound; he also advised the controller to stand by. The controller responded with a routine departure clearance; thus, the controller likely did not hear or understand the captain’s transmission. About 7 seconds later, the captain again declared an emergency and advised the controller to stand by. During the 30 seconds that followed, the captain reminded the first officer to fly the airplane on a heading of 220° and level off at 2,000 ft.
captain’s transmission. About 7 seconds later, the captain again declared an emergency and advised the controller to stand by. During the 30 seconds that followed, the captain reminded the first officer to fly the airplane on a heading of 220° and level off at 2,000 ft.
The controller then cleared the accident airplane for a visual approach to the airport, and the captain informed the controller that he and the first officer had to perform a checklist and would let her know when they were ready to return to the airport. The controller then asked the captain to keep her advised.
The process of declaring the emergency to ATC took 1 minute 53 seconds. During a postaccident interview, the captain stated that his communications with the controller “became a project” and that “it took a while for ATC to know what was going on” regarding the emergency. The captain added that those communications “took too much of [his] time away from the cockpit.” Although frequency congestion impeded the captain’s efforts to declare an emergency to ATC, the captain could have entered squawk code 7700 (indicating an emergency situation) into the transponder and deferred further radio communications until after the first officer stabilized the airplane in level flight.
In addition, about 25 seconds after the previous exchange between the controller and captain ended, the controller asked for more information about the emergency, including which engine was affected. The operator’s simulator guide stated that, after declaring an emergency involving a single-engine failure after V1, the captain could provide additional information to ATC when time permitted. Because further communication with ATC was not a priority at that time, the captain responded appropriately to the controller by stating that he would provide the information later.
The simulator guide also stated that, after declaring an emergency to ATC, selecting flaps to the UP position, reducing thrust, and establishing the airplane’s climb at 210 knots, the pilot flying was to fly, navigate, and communicate, and the pilot monitoring was to “reconfirm” the failure. However, much of the captain’s time by this point in the flight was spent listening and responding to ATC transmissions. Thus, communications between the captain and controller after the onset of the emergency caused interruptions that delayed the flight crew’s efforts to address the emergency situation.
While the captain was communicating with the controller, the first officer, as the pilot flying, incrementally reduced left and then right engine thrust to near flight idle so that the airplane could slow down after leveling off. The first officer stated that he had been trained in the simulator to move the thrust levers together until the crew was ready to confirm the affected engine. Thus, the first officer’s decision to independently move the left and then the right thrust lever was inappropriate.
When the captain turned his attention back to the airplane after communicating with the controller, both engines were near flight idle (the EPR was 1.05 and 1.12 for the left and right engine, respectively), and the airspeed was 227 knots and decreasing. The captain commanded a speed of 220 knots and then announced that he was taking control of the airplane. FDR data indicated that the captain did not promptly increase thrust after the airspeed subsequently dropped below the 220-knot target speed. During a postaccident interview, the captain stated that he was unaware that the first officer had reduced left engine thrust to near flight idle. The captain’s lack of awareness of the first officer’s thrust reductions played a role in his handling of the in-flight emergency, as discussed in the next section.
Misidentification of the Affected Engine and Failure to Verify
About 4 minutes elapsed between the time of the flight crew’s correct identification of the right engine as the affected engine and the first officer’s incorrect assessment about the left engine. This amount of time played a role in the first officer’s misidentification of the left engine as the affected engine. The first officer had a high workload during that time; as the pilot flying, he had to (among other things) closely monitor basic flight parameters and fly the airplane to achieve the target airspeed, altitude, and heading. The first officer was also dealing with interruptions due to the interspersing of various operational tasks. Although the first officer had previously verbalized that the right engine had lost power, the first officer’s workload demands left few opportunities for him to commit that information to memory. In addition, after the airplane had leveled off and the left and right EPR had been reduced to near flight idle, no adverse yaw (the primary cue indicating that the right engine was affected) was occurring, and the engine indications were ambiguous because both were producing low thrust (with the EPR on the left and right engines at 1.05 and 1.12, respectively).
Although thrust was low on both engines, the first officer might have thought that the left engine was affected because its EPR level was lower than that for the right engine. For that to be the case, the first officer would have had to have forgotten his earlier actions of pulling back the power on the left (operational) engine and then the right (damaged) engine to reduce airspeed.
The National Transportation Safety Board (NTSB) considered whether the first officer’s use of prescription medications played a role in (1) forgetting his and the captain’s initial correct diagnosis and his movement of the left thrust lever (along with the right thrust lever) to reduce airspeed and (2) asserting erroneously that the left engine was the affected engine. The NTSB's analysis of the potential side effects of these medications found that the use of these medications likely did not play a role in the accident.
The NTSB also considered whether the first officer’s errors were due to fatigue. Even though the errors that the first officer made were consistent with the effects of fatigue, the evidence supporting fatigue was inconclusive. Stress is also known to degrade cognitive functions such as working memory, attention, and reasoning, and it provides an alternate explanation for the first officer’s actions. The loss of right engine thrust at a low altitude over the ocean at night was a surprising and stressful event, especially for the first officer as the pilot flying at the time of the engine event.
The captain initially questioned the first officer’s assessment, stating “number one is gone?”, but then accepted the assessment and stated, “so we have number two.” At that time, no salient cue was available to indicate which engine was affected (due to the reduced thrust on both engines and the lack of adverse yaw). During a postaccident interview, the captain remembered his initial assessment that the right engine was affected but stated that he had assumed that the first officer had a better understanding of the engines’ status because he was flying the airplane when the captain was communicating the emergency to ATC.
The captain had confidence in the first officer’s assessment of the affected engine based on their flight experience together; during a postaccident interview, the captain stated that the first officer “never makes a mistake.” Nevertheless, the captain did not take any action to verify the first officer’s assessment about the left engine, such as advancing the thrust lever for the left engine to determine whether an increase in thrust occurred. The operator’s simulator guide stated that pilots should be alert for changes indicating that thrust was being reduced on the incorrect (operational) engine. However, the crew did not notice the reduction in adverse yaw that resulted from the first officer’s reduction of thrust on the left engine. Subsequently, the reductions in thrust on the left and right engines (which the first officer made to reduce airspeed) meant that there would be no noticeable indications that would have reinforced the idea to the crewmembers that the left engine was affected, as they determined initially.
If the captain had thought to test the thrust on the left engine by advancing the left thrust lever, the flight crew would likely have noticed an increase in left engine thrust, a yaw to the right, and engine sounds indicating that the left engine was capable of producing normal power. The captain could also have simultaneously advanced both thrust levers and observed the left engine producing more thrust. However, neither flight crewmember suggested that the captain perform these actions, and neither of these potential diagnostic steps was included in the operator’s Engine Failure or Shutdown checklist.
Further, the Engine Failure and Shutdown checklist would not have helped the captain sort out the situation because the checklist appeared to assume that the airplane would be experiencing ongoing asymmetric thrust, which was not the case at this point in the accident flight. The checklist did not consider the possibility that a flight crew would need to delay checklist execution until after completing steps in an operator’s single-engine departure procedure, such as leveling off at a low altitude and reducing thrust on both engines. Because there was no longer a clear sign of which engine had failed and the crew had forgotten its earlier determination that the right engine had lost power, critical thinking was required for the crew to devise diagnostic steps to confirm the affected engine. However, each pilot’s thinking was degraded by high workload and stress.
The operator’s simulator guide stated that, for a single-engine failure after V1, “the Captain, if not currently the PM [pilot monitoring], may (and most times should) elect to become the PM and run the…checklist.” Remaining in the pilot monitoring role (which was recommended but not required) would have preserved more of the captain’s mental resources to correctly diagnose and respond to the engine issue. The captain’s decision to assume the pilot flying role before reconfirming the engine issue increased his workload and decreased his ability to perceive and evaluate key information, such as the positioning of the thrust levers, the performance of the engines, and changes in the airplane’s energy state. Thus, the captain’s decision to take control of the airplane also decreased his ability to manage the crew’s response to the abnormal situation.
In addition, the captain’s lack of awareness of the left engine’s low commanded thrust level, along with the subsequent deterioration of the airplane’s energy state throughout the rest of the flight, played a role in his (1) failure to verify the first officer’s (incorrect) assertion about the left engine and (2) inability to detect the crew’s misidentification of the affected engine and cognitively reframe the situation. The NTSB considered whether fatigue played a role in the captain’s errors, but the evidence was inconclusive. These errors were likely the result of the captain’s high workload and stress. Research indicates that, under conditions of high workload and stress, “crews are vulnerable to missing important cues related to their situation and are likely to experience difficulty pulling together disparate pieces of information and making sense of them,” especially when “some of that information is incomplete, ambiguous, or contradictory.” (Burian, B.K., Barshi, I., and Dismukes, K., 2005).
The captain’s high workload increased further due to his decision to continue handling ATC radio communications, which occurred frequently on an ongoing basis throughout the flight. It is possible that the captain decided to maintain control of the radios based on information that he learned during the operator’s crew resource management (CRM) training. Specifically, the operator’s initial CRM training included a video that presented the circumstances of the September 2007 accident involving American Airlines flight 1400, including the distraction that radio communications caused the pilot monitoring while he attempted to execute the appropriate abnormal checklist. Thus, the captain of the Transair accident airplane might have thought that, by relieving the first officer of the responsibility of handling the radios, the first officer could focus his attention on performing the Engine Failure or Shutdown checklist (which is further discussed in the next section).
The captain’s ability to properly respond to the emergency was further diminished toward the end of the flight when he thought that the airplane could have a dual-engine failure, as demonstrated by his transmissions to the controller stating, “we might lose the other engine too” and, 2 minutes 19 seconds later, “there's a chance we're gonna lose the other engine too.” After the crewmembers noticed that the right engine was overheating, their attention became primarily focused on monitoring basic flight instruments and controlling the airplane. The crew’s communications and behavior during this latter portion of the flight were consistent with stress-related attentional narrowing, which restricts a person’s perceptions to the most salient cues and results in rigid thinking by reducing the number of alternatives that are considered (Stokes, A., and Kite, K.,1994). Attentional narrowing diminished the crew’s ability to understand and control the abnormal situation. As a result, the flight crew became fixated on monitoring the right EGT as well as basic flight parameters while manipulating only the right engine thrust lever.
Checklist Performance
The captain was aware that numerous steps in the operator’s Boeing 737-200 Engine Failure or Shutdown checklist were expected to be performed before the airplane could return to the airport. The previous criticism that the captain received from the company’s chief pilot for his handling of an earlier in-flight emergency (during which he returned to the airport without completing a required checklist) likely added pressure to the already-demanding situation of troubleshooting an engine issue while flying at a low altitude over the ocean at night.
The Engine Failure or Shutdown checklist defined three conditions that warranted the use of that checklist: an engine failure, an engine flameout, or another checklist that directed an engine shutdown. The checklist had 11 reference items, none of which were memory items. The Engine Failure or Shutdown checklist required pilots to confirm that the thrust lever for the affected engine was selected, move that thrust lever to the idle position, and shut down the corresponding engine. However, the checklist was not designed to help the crew identify the affected engine. Further, the operator’s simulator guide stated that the primary indications of an engine failure were a yawing moment and the rudder input required to counteract it, but neither was present at the time that the checklist was initiated. Thus, the simulator guidance did not reflect realistic operational conditions because it did not account for the possibility of a partial loss of thrust or a possible need to level off and reduce thrust on both engines before completing the checklist.
The captain called for the Engine Failure or Shutdown checklist about 4 minutes 26 seconds after the first indication of an engine problem. The captain’s communications with ATC after the onset of the emergency (as well as the need to assist the first officer in executing various aspects of the single-engine departure procedure) distracted the captain and precluded him from calling for the checklist sooner. The operator does not require its pilots to conduct the checklist immediately after an engine issue is detected. However, if the checklist had been started earlier in the accident sequence (that is, when adverse yaw was occurring or the EPR indications clearly showed which engine was producing lower thrust), and if fewer intervening distractions had occurred, the first officer might have recalled that he had reduced engine thrust to decrease the airplane’s speed, and both crewmembers might have recalled their initial (correct) diagnosis of the affected engine.
The first officer stated that he had accomplished “maybe a third or less” of the checklist, but the CVR showed that he had only read aloud the conditions for performing the checklist. The first officer further stated that he stopped the checklist (for the first time) because of the high EGT on the right engine (which he described as “beyond max”). Afterward, the captain stated that they should head toward the airport, which the first officer suggested about 1 minute earlier (before he started reading aloud the conditions for performing the checklist). The captain then asked the first officer to set up the instrument landing system approach, and the captain contacted the controller to let her know that the airplane was ready to return.
About 1 minute 35 seconds after the first officer informed the captain about the high EGT on the right engine, the captain instructed the first officer to “see what you can do in the checklist finish as much as possible.” About 15 seconds later, the first officer resumed reading aloud the conditions for performing the checklist but then stopped (for the second time) to state “we have to fly the airplane though” because the airplane was “slowing” or “low” and he thought that the captain was not focused on flying the airplane. Although the first officer likely thought that it was appropriate to focus on resolving the symptoms of the abnormal situation (the high EGT on the right engine and the airplane’s decreasing energy state) instead of performing the checklist, the first officer’s comments caused the crew’s attention to be directed away from confirming which engine was affected.
After the first officer advised the captain to focus on flying the airplane, the captain stated “okay” and did not redirect the first officer to continue the checklist. During a postaccident interview, the captain stated that, when he saw that the EPR for the right engine was decreasing and that there was “nothing coming out” of the left engine, he thought that performing the checklist would be “useless” because both engines had “already shut themselves down.” It is possible that performing the checklist’s third item, “AFFECTED ENGINE…CONFIRM…CLOSE” might have prompted the crew to shut down the incorrect (left) engine, which would not have prevented this accident. However, it is also possible that performing this checklist item might have led the crew to reconsider the source of the engine issue and the correct cause of the airplane’s deteriorating energy state. Thus, as a result of the flight crewmembers’ stress-related attention tunneling (which led to their thinking that a dual-engine failure was occurring and fixation on the right EGT and basic flight parameters), they neglected to perform a checklist item that might have alerted them about their misidentification of the affected engine.
The operator’s CRM training emphasized the importance of using checklists to manage abnormal situations and defend against error. During the accident flight, the captain and the first officer demonstrated ineffective CRM. Specifically, the captain did not ensure that the first officer, after his interjections while reading the conditions of the Engine Failure or Shutdown checklist, continued performing the checklist so that the affected engine could be confirmed. In addition, the captain demonstrated difficulties with task prioritization (an aspect of workload management) and leadership because, as pilot-in-command, he did not ensure that the checklist was accomplished, and he was distracted by lower-priority tasks, such as communicating with ATC. As a result, the flight crew was unable to coordinate an effective response to the emergency situation.
Emergency Response
The controller contacted the USCG Joint Rescue Coordination Center, which was responsible for coordinating US search and rescue activities in the Pacific Ocean, to report that the accident airplane was in the water. An aircraft rescue and firefighting (ARFF) rescue boat and a USCG helicopter from Barbers Point Air Station launched about 0200 and 0218, respectively.
The USCG helicopter arrived on scene about 0230 and located the accident airplane and crew. The captain was hanging onto the floating tail section of the airplane, and the first officer was on top of floating debris. The captain was struggling to stay afloat after the tail began to sink, and he was hoisted from the water to the helicopter with the assistance of a rescue diver. The diver then re-entered the water and swam with the first officer to the ARFF rescue boat, which had arrived on scene about 0240. The first officer received medical care once aboard the rescue boat.
The helicopter transported the captain directly to a local hospital. The rescue boat encountered high surf and low visibility while traveling back to the ARFF station, arriving about 0406. The first officer was then taken to the hospital; his delayed arrival there did not affect the treatment of his injuries, which were minor. Thus, the search and rescue operation was timely and effective.
Survival Factors
The captain and the first officer were wearing their restraints, including their shoulder harnesses, at the time of the accident. According to the first officer, his upper torso moved forward during impact, and his right shoulder rolled forward, downward, and to the left, which caused his body to twist so that he was facing to the left. The first officer’s head then moved downward, and the top of his head struck something in front of him, resulting in a minor head injury that did not impede his evacuation from the airplane.
Postaccident examination of the first officer’s seat found that the seatback had collapsed. Subsequent examination by the NTSB’s Materials Laboratory determined that the seatback collapse was due to the fracture of a jack nut that was part of a jackscrew assembly. The jack nut fractured in overstress due to loads that exceeded its load-bearing capacity.
The accident airplane model was certificated in December 1967, and the first officer’s seat was manufactured in September 1984. The seat complied with Technical Standard Order (TSO)-C39A, which was issued in February 1972. The TSO required the seat to meet a static load requirement of 9 G forward and 6 G downward. The loads that the first officer’s seat sustained during the ditching could not be determined from the available evidence for this investigation.
Newer seating systems are required to meet higher loads during certification. Specifically, crewmembers and passenger seating systems certificated under Title 14 Code of Federal Regulations Part 25 must currently meet, among other criteria, a dynamic requirement of 16 G forward and 14 G downward. These dynamic requirements apply to newly designed airplanes certificated after 1988 and all Part 25 airplanes manufactured after 2009, except for those that do not carry passengers for hire (including cargo-only airplanes, such as the accident airplane). According to the Federal Aviation Administration (FAA), four cargo 737-200 airplanes were registered in the United States as of November 2022, but the available evidence for this investigation did not indicate whether those airplanes were in active use.
- Probable Cause: The flight crewmembers’ misidentification of the damaged engine (after leveling off the airplane and reducing thrust) and their use of only the damaged engine for thrust during the remainder of the flight, resulting in an unintentional descent and forced ditching in the Pacific Ocean. Contributing to the accident were the flight crew’s ineffective crew resource management, high workload, and stress.
- Report:
- Docket:
data.ntsb.gov
Because of the high temperature readings on the right engine, the flight crew thought, at this point in the flight, that a dual-engine failure was imminent. During a postaccident interview, the captain stated that his priority at that time was figuring out how the airplane could stay in the air and return safely to the airport. The captain also stated that he attempted to resolve the airplane’s deteriorating energy state by advancing the right engine thrust lever. However, with the left engine remaining near flight idle, the right engine was not producing sufficient thrust to enable the airplane to maintain altitude or climb.
The captain’s communication with the controller continued, and the first officer stated, “fly the airplane please.” The controller asked if the airport was in sight, and the captain then asked the first officer whether he could see the airport. The first officer responded “pull up we’re low” to the captain and “negative” to the controller; the captain was likely unable to respond to the controller because he was trying to control the airplane.
The captain asked the first officer about the EGT for the right engine; the first officer replied “hot…way over.” The captain then asked about, and the controller responded by providing, the location of the closest airport. Afterward, the CVR recorded a sound similar to the stick shaker, which continued intermittently through the rest of the flight. The CVR then recorded sounds consistent with water impact.
The aircraft performance study for this accident found that the airplane had adequate total engine thrust available to climb, accelerate, and maintain altitude both before and after the rapid decrease in right EPR to 1.43. However, as the left EPR decreased and remained below a level of 1.2 (which occurred about 35 seconds after the airplane leveled off at 2,000 ft and while the EPR on the right engine was about 1.4), total engine thrust decreased to the point that the airplane transitioned to and remained at a low-energy state (that is, low total engine thrust, low airspeed, and low altitude). The flight crew relied exclusively on thrust from the damaged right engine as thrust on the left engine remained near flight idle. With this engine power configuration, the flight crew could not arrest the airplane’s descent, and the airplane was unable to maintain altitude, accelerate, or climb because the flight crew did not take the corrective action of adding left engine thrust, which was available.
Right Engine Loss of Thrust and Left Engine Pressure Ratio Decrease
The rotational signatures observed during postaccident examination of both engines indicated that the right engine was rotating at a much faster speed at impact than the left engine. The indications showing low rotation of the left engine core at impact were consistent with the engine operating near flight idle at that time. Postaccident examination of the left engine found no anomalies that would have caused the reduced thrust on that engine.
The teardown of the right engine showed that two high-pressure turbine stage 1 blades were missing their outer spans and that both had failed from a stress rupture fracture due to oxidation and corrosion of the internal blade lightening (weight-reduction) holes, which resulted in a loss of load-bearing cross-section. The blade failures caused downstream (secondary) damage to the low-pressure turbine, resulting in a loss of thrust, which would have been presented to the flight crew as a decrease in EPR on the right engine (along with the thud sound recorded on the CVR and the yaw to the right).
Postaccident examination of the high-pressure turbine stage 1 right engine blades also revealed that they had been exposed to temperatures beyond the blades’ normal operating range, resulting in microstructure changes to the blade material. According to flight crew postaccident interviews as well as CVR evidence, the right EGT was at the top of the gauge (at or above the red line). Also, the operator’s Boeing 737 Aircraft Operations Manual stated that the maximum continuous EGT for the airplane’s engines was 540°C, but the EGT gauge was found in the wreckage indicating 700°C. Thus, the overtemperature damage on the right engine blades likely occurred during the accident flight when the engine was operated at elevated temperatures.
Notification to Controller About Emergency and Engine Thrust Reductions
The captain first declared an emergency to the controller about 36 seconds after the CVR recorded the thud sound; he also advised the controller to stand by. The controller responded with a routine departure clearance; thus, the controller likely did not hear or understand the captain’s transmission. About 7 seconds later, the captain again declared an emergency and advised the controller to stand by. During the 30 seconds that followed, the captain reminded the first officer to fly the airplane on a heading of 220° and level off at 2,000 ft.
captain’s transmission. About 7 seconds later, the captain again declared an emergency and advised the controller to stand by. During the 30 seconds that followed, the captain reminded the first officer to fly the airplane on a heading of 220° and level off at 2,000 ft.
The controller then cleared the accident airplane for a visual approach to the airport, and the captain informed the controller that he and the first officer had to perform a checklist and would let her know when they were ready to return to the airport. The controller then asked the captain to keep her advised.
The process of declaring the emergency to ATC took 1 minute 53 seconds. During a postaccident interview, the captain stated that his communications with the controller “became a project” and that “it took a while for ATC to know what was going on” regarding the emergency. The captain added that those communications “took too much of [his] time away from the cockpit.” Although frequency congestion impeded the captain’s efforts to declare an emergency to ATC, the captain could have entered squawk code 7700 (indicating an emergency situation) into the transponder and deferred further radio communications until after the first officer stabilized the airplane in level flight.
In addition, about 25 seconds after the previous exchange between the controller and captain ended, the controller asked for more information about the emergency, including which engine was affected. The operator’s simulator guide stated that, after declaring an emergency involving a single-engine failure after V1, the captain could provide additional information to ATC when time permitted. Because further communication with ATC was not a priority at that time, the captain responded appropriately to the controller by stating that he would provide the information later.
The simulator guide also stated that, after declaring an emergency to ATC, selecting flaps to the UP position, reducing thrust, and establishing the airplane’s climb at 210 knots, the pilot flying was to fly, navigate, and communicate, and the pilot monitoring was to “reconfirm” the failure. However, much of the captain’s time by this point in the flight was spent listening and responding to ATC transmissions. Thus, communications between the captain and controller after the onset of the emergency caused interruptions that delayed the flight crew’s efforts to address the emergency situation.
While the captain was communicating with the controller, the first officer, as the pilot flying, incrementally reduced left and then right engine thrust to near flight idle so that the airplane could slow down after leveling off. The first officer stated that he had been trained in the simulator to move the thrust levers together until the crew was ready to confirm the affected engine. Thus, the first officer’s decision to independently move the left and then the right thrust lever was inappropriate.
When the captain turned his attention back to the airplane after communicating with the controller, both engines were near flight idle (the EPR was 1.05 and 1.12 for the left and right engine, respectively), and the airspeed was 227 knots and decreasing. The captain commanded a speed of 220 knots and then announced that he was taking control of the airplane. FDR data indicated that the captain did not promptly increase thrust after the airspeed subsequently dropped below the 220-knot target speed. During a postaccident interview, the captain stated that he was unaware that the first officer had reduced left engine thrust to near flight idle. The captain’s lack of awareness of the first officer’s thrust reductions played a role in his handling of the in-flight emergency, as discussed in the next section.
Misidentification of the Affected Engine and Failure to Verify
About 4 minutes elapsed between the time of the flight crew’s correct identification of the right engine as the affected engine and the first officer’s incorrect assessment about the left engine. This amount of time played a role in the first officer’s misidentification of the left engine as the affected engine. The first officer had a high workload during that time; as the pilot flying, he had to (among other things) closely monitor basic flight parameters and fly the airplane to achieve the target airspeed, altitude, and heading. The first officer was also dealing with interruptions due to the interspersing of various operational tasks. Although the first officer had previously verbalized that the right engine had lost power, the first officer’s workload demands left few opportunities for him to commit that information to memory. In addition, after the airplane had leveled off and the left and right EPR had been reduced to near flight idle, no adverse yaw (the primary cue indicating that the right engine was affected) was occurring, and the engine indications were ambiguous because both were producing low thrust (with the EPR on the left and right engines at 1.05 and 1.12, respectively).
Although thrust was low on both engines, the first officer might have thought that the left engine was affected because its EPR level was lower than that for the right engine. For that to be the case, the first officer would have had to have forgotten his earlier actions of pulling back the power on the left (operational) engine and then the right (damaged) engine to reduce airspeed.
The National Transportation Safety Board (NTSB) considered whether the first officer’s use of prescription medications played a role in (1) forgetting his and the captain’s initial correct diagnosis and his movement of the left thrust lever (along with the right thrust lever) to reduce airspeed and (2) asserting erroneously that the left engine was the affected engine. The NTSB's analysis of the potential side effects of these medications found that the use of these medications likely did not play a role in the accident.
The NTSB also considered whether the first officer’s errors were due to fatigue. Even though the errors that the first officer made were consistent with the effects of fatigue, the evidence supporting fatigue was inconclusive. Stress is also known to degrade cognitive functions such as working memory, attention, and reasoning, and it provides an alternate explanation for the first officer’s actions. The loss of right engine thrust at a low altitude over the ocean at night was a surprising and stressful event, especially for the first officer as the pilot flying at the time of the engine event.
The captain initially questioned the first officer’s assessment, stating “number one is gone?”, but then accepted the assessment and stated, “so we have number two.” At that time, no salient cue was available to indicate which engine was affected (due to the reduced thrust on both engines and the lack of adverse yaw). During a postaccident interview, the captain remembered his initial assessment that the right engine was affected but stated that he had assumed that the first officer had a better understanding of the engines’ status because he was flying the airplane when the captain was communicating the emergency to ATC.
The captain had confidence in the first officer’s assessment of the affected engine based on their flight experience together; during a postaccident interview, the captain stated that the first officer “never makes a mistake.” Nevertheless, the captain did not take any action to verify the first officer’s assessment about the left engine, such as advancing the thrust lever for the left engine to determine whether an increase in thrust occurred. The operator’s simulator guide stated that pilots should be alert for changes indicating that thrust was being reduced on the incorrect (operational) engine. However, the crew did not notice the reduction in adverse yaw that resulted from the first officer’s reduction of thrust on the left engine. Subsequently, the reductions in thrust on the left and right engines (which the first officer made to reduce airspeed) meant that there would be no noticeable indications that would have reinforced the idea to the crewmembers that the left engine was affected, as they determined initially.
If the captain had thought to test the thrust on the left engine by advancing the left thrust lever, the flight crew would likely have noticed an increase in left engine thrust, a yaw to the right, and engine sounds indicating that the left engine was capable of producing normal power. The captain could also have simultaneously advanced both thrust levers and observed the left engine producing more thrust. However, neither flight crewmember suggested that the captain perform these actions, and neither of these potential diagnostic steps was included in the operator’s Engine Failure or Shutdown checklist.
Further, the Engine Failure and Shutdown checklist would not have helped the captain sort out the situation because the checklist appeared to assume that the airplane would be experiencing ongoing asymmetric thrust, which was not the case at this point in the accident flight. The checklist did not consider the possibility that a flight crew would need to delay checklist execution until after completing steps in an operator’s single-engine departure procedure, such as leveling off at a low altitude and reducing thrust on both engines. Because there was no longer a clear sign of which engine had failed and the crew had forgotten its earlier determination that the right engine had lost power, critical thinking was required for the crew to devise diagnostic steps to confirm the affected engine. However, each pilot’s thinking was degraded by high workload and stress.
The operator’s simulator guide stated that, for a single-engine failure after V1, “the Captain, if not currently the PM [pilot monitoring], may (and most times should) elect to become the PM and run the…checklist.” Remaining in the pilot monitoring role (which was recommended but not required) would have preserved more of the captain’s mental resources to correctly diagnose and respond to the engine issue. The captain’s decision to assume the pilot flying role before reconfirming the engine issue increased his workload and decreased his ability to perceive and evaluate key information, such as the positioning of the thrust levers, the performance of the engines, and changes in the airplane’s energy state. Thus, the captain’s decision to take control of the airplane also decreased his ability to manage the crew’s response to the abnormal situation.
In addition, the captain’s lack of awareness of the left engine’s low commanded thrust level, along with the subsequent deterioration of the airplane’s energy state throughout the rest of the flight, played a role in his (1) failure to verify the first officer’s (incorrect) assertion about the left engine and (2) inability to detect the crew’s misidentification of the affected engine and cognitively reframe the situation. The NTSB considered whether fatigue played a role in the captain’s errors, but the evidence was inconclusive. These errors were likely the result of the captain’s high workload and stress. Research indicates that, under conditions of high workload and stress, “crews are vulnerable to missing important cues related to their situation and are likely to experience difficulty pulling together disparate pieces of information and making sense of them,” especially when “some of that information is incomplete, ambiguous, or contradictory.” (Burian, B.K., Barshi, I., and Dismukes, K., 2005).
The captain’s high workload increased further due to his decision to continue handling ATC radio communications, which occurred frequently on an ongoing basis throughout the flight. It is possible that the captain decided to maintain control of the radios based on information that he learned during the operator’s crew resource management (CRM) training. Specifically, the operator’s initial CRM training included a video that presented the circumstances of the September 2007 accident involving American Airlines flight 1400, including the distraction that radio communications caused the pilot monitoring while he attempted to execute the appropriate abnormal checklist. Thus, the captain of the Transair accident airplane might have thought that, by relieving the first officer of the responsibility of handling the radios, the first officer could focus his attention on performing the Engine Failure or Shutdown checklist (which is further discussed in the next section).
The captain’s ability to properly respond to the emergency was further diminished toward the end of the flight when he thought that the airplane could have a dual-engine failure, as demonstrated by his transmissions to the controller stating, “we might lose the other engine too” and, 2 minutes 19 seconds later, “there's a chance we're gonna lose the other engine too.” After the crewmembers noticed that the right engine was overheating, their attention became primarily focused on monitoring basic flight instruments and controlling the airplane. The crew’s communications and behavior during this latter portion of the flight were consistent with stress-related attentional narrowing, which restricts a person’s perceptions to the most salient cues and results in rigid thinking by reducing the number of alternatives that are considered (Stokes, A., and Kite, K.,1994). Attentional narrowing diminished the crew’s ability to understand and control the abnormal situation. As a result, the flight crew became fixated on monitoring the right EGT as well as basic flight parameters while manipulating only the right engine thrust lever.
Checklist Performance
The captain was aware that numerous steps in the operator’s Boeing 737-200 Engine Failure or Shutdown checklist were expected to be performed before the airplane could return to the airport. The previous criticism that the captain received from the company’s chief pilot for his handling of an earlier in-flight emergency (during which he returned to the airport without completing a required checklist) likely added pressure to the already-demanding situation of troubleshooting an engine issue while flying at a low altitude over the ocean at night.
The Engine Failure or Shutdown checklist defined three conditions that warranted the use of that checklist: an engine failure, an engine flameout, or another checklist that directed an engine shutdown. The checklist had 11 reference items, none of which were memory items. The Engine Failure or Shutdown checklist required pilots to confirm that the thrust lever for the affected engine was selected, move that thrust lever to the idle position, and shut down the corresponding engine. However, the checklist was not designed to help the crew identify the affected engine. Further, the operator’s simulator guide stated that the primary indications of an engine failure were a yawing moment and the rudder input required to counteract it, but neither was present at the time that the checklist was initiated. Thus, the simulator guidance did not reflect realistic operational conditions because it did not account for the possibility of a partial loss of thrust or a possible need to level off and reduce thrust on both engines before completing the checklist.
The captain called for the Engine Failure or Shutdown checklist about 4 minutes 26 seconds after the first indication of an engine problem. The captain’s communications with ATC after the onset of the emergency (as well as the need to assist the first officer in executing various aspects of the single-engine departure procedure) distracted the captain and precluded him from calling for the checklist sooner. The operator does not require its pilots to conduct the checklist immediately after an engine issue is detected. However, if the checklist had been started earlier in the accident sequence (that is, when adverse yaw was occurring or the EPR indications clearly showed which engine was producing lower thrust), and if fewer intervening distractions had occurred, the first officer might have recalled that he had reduced engine thrust to decrease the airplane’s speed, and both crewmembers might have recalled their initial (correct) diagnosis of the affected engine.
The first officer stated that he had accomplished “maybe a third or less” of the checklist, but the CVR showed that he had only read aloud the conditions for performing the checklist. The first officer further stated that he stopped the checklist (for the first time) because of the high EGT on the right engine (which he described as “beyond max”). Afterward, the captain stated that they should head toward the airport, which the first officer suggested about 1 minute earlier (before he started reading aloud the conditions for performing the checklist). The captain then asked the first officer to set up the instrument landing system approach, and the captain contacted the controller to let her know that the airplane was ready to return.
About 1 minute 35 seconds after the first officer informed the captain about the high EGT on the right engine, the captain instructed the first officer to “see what you can do in the checklist finish as much as possible.” About 15 seconds later, the first officer resumed reading aloud the conditions for performing the checklist but then stopped (for the second time) to state “we have to fly the airplane though” because the airplane was “slowing” or “low” and he thought that the captain was not focused on flying the airplane. Although the first officer likely thought that it was appropriate to focus on resolving the symptoms of the abnormal situation (the high EGT on the right engine and the airplane’s decreasing energy state) instead of performing the checklist, the first officer’s comments caused the crew’s attention to be directed away from confirming which engine was affected.
After the first officer advised the captain to focus on flying the airplane, the captain stated “okay” and did not redirect the first officer to continue the checklist. During a postaccident interview, the captain stated that, when he saw that the EPR for the right engine was decreasing and that there was “nothing coming out” of the left engine, he thought that performing the checklist would be “useless” because both engines had “already shut themselves down.” It is possible that performing the checklist’s third item, “AFFECTED ENGINE…CONFIRM…CLOSE” might have prompted the crew to shut down the incorrect (left) engine, which would not have prevented this accident. However, it is also possible that performing this checklist item might have led the crew to reconsider the source of the engine issue and the correct cause of the airplane’s deteriorating energy state. Thus, as a result of the flight crewmembers’ stress-related attention tunneling (which led to their thinking that a dual-engine failure was occurring and fixation on the right EGT and basic flight parameters), they neglected to perform a checklist item that might have alerted them about their misidentification of the affected engine.
The operator’s CRM training emphasized the importance of using checklists to manage abnormal situations and defend against error. During the accident flight, the captain and the first officer demonstrated ineffective CRM. Specifically, the captain did not ensure that the first officer, after his interjections while reading the conditions of the Engine Failure or Shutdown checklist, continued performing the checklist so that the affected engine could be confirmed. In addition, the captain demonstrated difficulties with task prioritization (an aspect of workload management) and leadership because, as pilot-in-command, he did not ensure that the checklist was accomplished, and he was distracted by lower-priority tasks, such as communicating with ATC. As a result, the flight crew was unable to coordinate an effective response to the emergency situation.
Emergency Response
The controller contacted the USCG Joint Rescue Coordination Center, which was responsible for coordinating US search and rescue activities in the Pacific Ocean, to report that the accident airplane was in the water. An aircraft rescue and firefighting (ARFF) rescue boat and a USCG helicopter from Barbers Point Air Station launched about 0200 and 0218, respectively.
The USCG helicopter arrived on scene about 0230 and located the accident airplane and crew. The captain was hanging onto the floating tail section of the airplane, and the first officer was on top of floating debris. The captain was struggling to stay afloat after the tail began to sink, and he was hoisted from the water to the helicopter with the assistance of a rescue diver. The diver then re-entered the water and swam with the first officer to the ARFF rescue boat, which had arrived on scene about 0240. The first officer received medical care once aboard the rescue boat.
The helicopter transported the captain directly to a local hospital. The rescue boat encountered high surf and low visibility while traveling back to the ARFF station, arriving about 0406. The first officer was then taken to the hospital; his delayed arrival there did not affect the treatment of his injuries, which were minor. Thus, the search and rescue operation was timely and effective.
Survival Factors
The captain and the first officer were wearing their restraints, including their shoulder harnesses, at the time of the accident. According to the first officer, his upper torso moved forward during impact, and his right shoulder rolled forward, downward, and to the left, which caused his body to twist so that he was facing to the left. The first officer’s head then moved downward, and the top of his head struck something in front of him, resulting in a minor head injury that did not impede his evacuation from the airplane.
Postaccident examination of the first officer’s seat found that the seatback had collapsed. Subsequent examination by the NTSB’s Materials Laboratory determined that the seatback collapse was due to the fracture of a jack nut that was part of a jackscrew assembly. The jack nut fractured in overstress due to loads that exceeded its load-bearing capacity.
The accident airplane model was certificated in December 1967, and the first officer’s seat was manufactured in September 1984. The seat complied with Technical Standard Order (TSO)-C39A, which was issued in February 1972. The TSO required the seat to meet a static load requirement of 9 G forward and 6 G downward. The loads that the first officer’s seat sustained during the ditching could not be determined from the available evidence for this investigation.
Newer seating systems are required to meet higher loads during certification. Specifically, crewmembers and passenger seating systems certificated under Title 14 Code of Federal Regulations Part 25 must currently meet, among other criteria, a dynamic requirement of 16 G forward and 14 G downward. These dynamic requirements apply to newly designed airplanes certificated after 1988 and all Part 25 airplanes manufactured after 2009, except for those that do not carry passengers for hire (including cargo-only airplanes, such as the accident airplane). According to the Federal Aviation Administration (FAA), four cargo 737-200 airplanes were registered in the United States as of November 2022, but the available evidence for this investigation did not indicate whether those airplanes were in active use.
- Probable Cause: The flight crewmembers’ misidentification of the damaged engine (after leveling off the airplane and reducing thrust) and their use of only the damaged engine for thrust during the remainder of the flight, resulting in an unintentional descent and forced ditching in the Pacific Ocean. Contributing to the accident were the flight crew’s ineffective crew resource management, high workload, and stress.
- Report:
- Docket:
NTSB Docket - Docket Management System
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Well-Known Member
- NTSB issues the final report into an accident involving Transair flight 810, a Boeing 737-275C Adv. cargo plane, N810TA, that occurred on July 2, 2021, off Honolulu, Hawaii:
On July 2, 2021, about 0145 Hawaii-Aleutian standard time, Rhoades Aviation flight 810, dba Transair flight 810, a Boeing 737-200, N810TA, experienced an engine anomaly shortly after takeoff from Daniel K. Inouye International Airport (HNL), Honolulu, Hawaii, and was subsequently ditched into Mamala Bay (in the Pacific Ocean), about 5.5 miles southwest of HNL. The captain sustained serious injuries, the first officer sustained minor injuries, and the airplane was destroyed. The flight was operating under Title 14 Code of Federal Regulations Part 121 as a cargo flight from HNL to Kahului International Airport (OGG), Kahului, Hawaii.
Transair flight 810, a Title 14 Code of Federal Regulations Part 121 cargo flight, experienced a partial loss of power involving the right engine shortly after takeoff and a water ditching in the Pacific Ocean about 11.5 minutes later. This analysis summarizes the accident and evaluates (1) the right engine partial loss of power, (2) the captain's communications with air traffic control (ATC) and the first officer's left and right engine thrust reductions, (3) the first officer's misidentification of the affected engine and the captain's failure to verify the information, (4) checklist performance, and (5) survival factors. Maintenance was not a factor in this accident.
The flight data recorder (FDR) showed that, when the initial thrust was set for takeoff, the engine pressure ratios (EPR) for the left and right engines were 2.00 and 1.97, respectively. Shortly after rotation, the cockpit voice recorder (CVR) recorded a “thud” and the sound of a low-frequency vibration. The captain (the pilot monitoring at the time) and the first officer (the pilot flying) reported that they heard a “whoosh” and a “pop,” respectively, at that time. As the airplane climbed through an altitude of about 390 ft while at an airspeed of 155 knots, the right EPR decreased to 1.43 during a 2-second period. The airplane then yawed to the right; the first officer countered the yaw with appropriate left rudder pedal inputs. The CVR showed that the captain and the first officer correctly determined that the No. 2 (right) engine had lost thrust within 5 seconds of hearing the thud sound.
After moving the flaps to the UP position, the captain reduced thrust to maximum continuous thrust, causing the left EPR to decrease from 1.96 to 1.91 while the airplane was in a climb. (The right EPR remained at 1.43). The captain reported that he did not move the thrust levers again until after he became the pilot flying. The first officer stated that, after the airplane leveled off at an altitude of about 2,000 ft, he reduced thrust on both engines. FDR data showed that thrust was incrementally reduced to near flight idle (1.05 EPR on the left engine and then 1.09 EPR on the right engine) and that airspeed decreased from about 250 to 210 knots. (A decrease in airspeed to 210 knots was consistent with the operator’s simulator guide procedures for a single-engine failure after the takeoff decision speed [V1]. The simulator guide, which supplemented information in the company’s flight crew training manual, contained the most recent operator guidance for single-engine failure training at the time of the accident.)
The captain was unaware of the first officer’s thrust changes because he was busy contacting the controller about the emergency. The captain told the controller, “we’ve lost an engine,” but he had declared the emergency to the controller twice before this point, as discussed later in this analysis.
The captain instructed the first officer to maintain a target speed of 220 knots (which the captain thought would be “easy on the running engine”), a target altitude of 2,000 ft, and a target heading of 240°. (About 52 seconds earlier, the controller had issued the 240° heading instruction to another airplane on the same radio frequency.) About 3 minutes 14 seconds after the right engine loss of thrust occurred, the captain assumed control of the airplane; at that time, the airplane’s airspeed was 224 knots and heading was 242°, but the airplane’s altitude had decreased from about 2,100 ft (the maximum altitude that the airplane reached during the flight) to 1,690 ft. The captain increased the airplane’s pitch to 9°; the airplane’s altitude then increased to 1,878 ft, but the airspeed decreased to 196 knots.
The captain subsequently stated, “let’s see what is the problem...which one...what's going on with the gauges,” and “who has the E-G-T [exhaust gas temperature]?” The first officer stated that the left engine was “gone” and “so we have number two” (the right engine), thus misidentifying the affected engine. The captain accepted the first officer’s assessment and did not take action to verify the information. Afterward, the EPR level on the right engine began to increase in response to the captain advancing the right thrust lever so that the airplane could maintain airspeed and altitude. Right EPR increased and decreased several times during the rest of the flight (coinciding with crew comments regarding the EGT on the right engine and low airspeed) while the left EPR remained near flight idle.
The first officer asked the captain if they “should head back toward the airport” before the airplane traveled “too far away,” and the captain responded that the airplane would stay within 15 miles of the airport. During a postaccident interview, the captain stated that, because there was no fire and an engine “was running,” he intended to have the airplane climb to 2,000 ft and stay within 15 miles of the airport to avoid traffic and have time to address the engine issue. The captain also stated that he had been criticized by the company chief pilot for returning to the airport without completing the required abnormal checklist for a previous in-flight emergency. Although the captain’s decision resulted in the accident airplane flying farther away from the airport and farther over the ocean at night, the captain’s decision was reasonable for a single-engine failure event.
The captain directed the first officer to begin the Engine Failure or Shutdown checklist and stated that he would continue handling the radios. The first officer began to read aloud the conditions for executing the Engine Failure or Shutdown checklist but then stopped to tell the captain that the right EGT was at the “red line” and that thrust should be reduced on the right engine. The captain then decided that the airplane should return to the airport and contacted the controller to request vectors.
The flight crew continued to express concern about the right engine. The first officer stated, “just have to watch this though…the number two.” The captain asked the first officer to check the EGT for the right engine, and the first officer responded that it was “beyond max.” Afterward, the captain told the first officer to continue with the Engine Failure or Shutdown checklist and finish as much as possible. The first officer resumed reading aloud the conditions for performing the checklist but then stopped to state, “we have to fly the airplane though,” because the airplane was continuing to lose altitude and airspeed. The captain replied “okay.” As a result, the flight crew did not perform key steps of the checklist, including identifying, confirming, and shutting down the affected (right) engine.
The first officer told the captain that the airplane was losing altitude; at that time, the airplane’s altitude was 592 ft, and its airspeed was 160 knots. The captain agreed to select flaps 1 (which the first officer had previously suggested likely because the airplane was slowing). The CVR then recorded the first enhanced ground proximity warning system (EGPWS) annunciation (500 ft above ground level); various EGPWS callouts and alerts continued to be annunciated through the remainder of the flight. The captain then told the controller that “we’ve lost number one
engine…there’s a chance we’re gonna lose the other engine too it’s running very hot….we’re pretty low on the speed it doesn't look good out here.” Also, the captain mentioned that the controller should notify the US Coast Guard (USCG) because he was anticipating a water ditching in the Pacific Ocean.
Because of the high temperature readings on the right engine, the flight crew thought, at this point in the flight, that a dual-engine failure was imminent. During a postaccident interview, the captain stated that his priority at that time was figuring out how the airplane could stay in the air and return safely to the airport. The captain also stated that he attempted to resolve the airplane’s deteriorating energy state by advancing the right engine thrust lever. However, with the left engine remaining near flight idle, the right engine was not producing sufficient thrust to enable the airplane to maintain altitude or climb.
The captain’s communication with the controller continued, and the first officer stated, “fly the airplane please.” The controller asked if the airport was in sight, and the captain then asked the first officer whether he could see the airport. The first officer responded “pull up we’re low” to the captain and “negative” to the controller; the captain was likely unable to respond to the controller because he was trying to control the airplane.
The captain asked the first officer about the EGT for the right engine; the first officer replied “hot…way over.” The captain then asked about, and the controller responded by providing, the location of the closest airport. Afterward, the CVR recorded a sound similar to the stick shaker, which continued intermittently through the rest of the flight. The CVR then recorded sounds consistent with water impact.
The aircraft performance study for this accident found that the airplane had adequate total engine thrust available to climb, accelerate, and maintain altitude both before and after the rapid decrease in right EPR to 1.43. However, as the left EPR decreased and remained below a level of 1.2 (which occurred about 35 seconds after the airplane leveled off at 2,000 ft and while the EPR on the right engine was about 1.4), total engine thrust decreased to the point that the airplane transitioned to and remained at a low-energy state (that is, low total engine thrust, low airspeed, and low altitude). The flight crew relied exclusively on thrust from the damaged right engine as thrust on the left engine remained near flight idle. With this engine power configuration, the flight crew could not arrest the airplane’s descent, and the airplane was unable to maintain altitude, accelerate, or climb because the flight crew did not take the corrective action of adding left engine thrust, which was available.
Right Engine Loss of Thrust and Left Engine Pressure Ratio Decrease
The rotational signatures observed during postaccident examination of both engines indicated that the right engine was rotating at a much faster speed at impact than the left engine. The indications showing low rotation of the left engine core at impact were consistent with the engine operating near flight idle at that time. Postaccident examination of the left engine found no anomalies that would have caused the reduced thrust on that engine.
The teardown of the right engine showed that two high-pressure turbine stage 1 blades were missing their outer spans and that both had failed from a stress rupture fracture due to oxidation and corrosion of the internal blade lightening (weight-reduction) holes, which resulted in a loss of load-bearing cross-section. The blade failures caused downstream (secondary) damage to the low-pressure turbine, resulting in a loss of thrust, which would have been presented to the flight crew as a decrease in EPR on the right engine (along with the thud sound recorded on the CVR and the yaw to the right).
Postaccident examination of the high-pressure turbine stage 1 right engine blades also revealed that they had been exposed to temperatures beyond the blades’ normal operating range, resulting in microstructure changes to the blade material. According to flight crew postaccident interviews as well as CVR evidence, the right EGT was at the top of the gauge (at or above the red line). Also, the operator’s Boeing 737 Aircraft Operations Manual stated that the maximum continuous EGT for the airplane’s engines was 540°C, but the EGT gauge was found in the wreckage indicating 700°C. Thus, the overtemperature damage on the right engine blades likely occurred during the accident flight when the engine was operated at elevated temperatures.
Notification to Controller About Emergency and Engine Thrust Reductions
The captain first declared an emergency to the controller about 36 seconds after the CVR recorded the thud sound; he also advised the controller to stand by. The controller responded with a routine departure clearance; thus, the controller likely did not hear or understand the captain’s transmission. About 7 seconds later, the captain again declared an emergency and advised the controller to stand by. During the 30 seconds that followed, the captain reminded the first officer to fly the airplane on a heading of 220° and level off at 2,000 ft.
captain’s transmission. About 7 seconds later, the captain again declared an emergency and advised the controller to stand by. During the 30 seconds that followed, the captain reminded the first officer to fly the airplane on a heading of 220° and level off at 2,000 ft.
The controller then cleared the accident airplane for a visual approach to the airport, and the captain informed the controller that he and the first officer had to perform a checklist and would let her know when they were ready to return to the airport. The controller then asked the captain to keep her advised.
The process of declaring the emergency to ATC took 1 minute 53 seconds. During a postaccident interview, the captain stated that his communications with the controller “became a project” and that “it took a while for ATC to know what was going on” regarding the emergency. The captain added that those communications “took too much of [his] time away from the cockpit.” Although frequency congestion impeded the captain’s efforts to declare an emergency to ATC, the captain could have entered squawk code 7700 (indicating an emergency situation) into the transponder and deferred further radio communications until after the first officer stabilized the airplane in level flight.
In addition, about 25 seconds after the previous exchange between the controller and captain ended, the controller asked for more information about the emergency, including which engine was affected. The operator’s simulator guide stated that, after declaring an emergency involving a single-engine failure after V1, the captain could provide additional information to ATC when time permitted. Because further communication with ATC was not a priority at that time, the captain responded appropriately to the controller by stating that he would provide the information later.
The simulator guide also stated that, after declaring an emergency to ATC, selecting flaps to the UP position, reducing thrust, and establishing the airplane’s climb at 210 knots, the pilot flying was to fly, navigate, and communicate, and the pilot monitoring was to “reconfirm” the failure. However, much of the captain’s time by this point in the flight was spent listening and responding to ATC transmissions. Thus, communications between the captain and controller after the onset of the emergency caused interruptions that delayed the flight crew’s efforts to address the emergency situation.
While the captain was communicating with the controller, the first officer, as the pilot flying, incrementally reduced left and then right engine thrust to near flight idle so that the airplane could slow down after leveling off. The first officer stated that he had been trained in the simulator to move the thrust levers together until the crew was ready to confirm the affected engine. Thus, the first officer’s decision to independently move the left and then the right thrust lever was inappropriate.
When the captain turned his attention back to the airplane after communicating with the controller, both engines were near flight idle (the EPR was 1.05 and 1.12 for the left and right engine, respectively), and the airspeed was 227 knots and decreasing. The captain commanded a speed of 220 knots and then announced that he was taking control of the airplane. FDR data indicated that the captain did not promptly increase thrust after the airspeed subsequently dropped below the 220-knot target speed. During a postaccident interview, the captain stated that he was unaware that the first officer had reduced left engine thrust to near flight idle. The captain’s lack of awareness of the first officer’s thrust reductions played a role in his handling of the in-flight emergency, as discussed in the next section.
Misidentification of the Affected Engine and Failure to Verify
About 4 minutes elapsed between the time of the flight crew’s correct identification of the right engine as the affected engine and the first officer’s incorrect assessment about the left engine. This amount of time played a role in the first officer’s misidentification of the left engine as the affected engine. The first officer had a high workload during that time; as the pilot flying, he had to (among other things) closely monitor basic flight parameters and fly the airplane to achieve the target airspeed, altitude, and heading. The first officer was also dealing with interruptions due to the interspersing of various operational tasks. Although the first officer had previously verbalized that the right engine had lost power, the first officer’s workload demands left few opportunities for him to commit that information to memory. In addition, after the airplane had leveled off and the left and right EPR had been reduced to near flight idle, no adverse yaw (the primary cue indicating that the right engine was affected) was occurring, and the engine indications were ambiguous because both were producing low thrust (with the EPR on the left and right engines at 1.05 and 1.12, respectively).
Although thrust was low on both engines, the first officer might have thought that the left engine was affected because its EPR level was lower than that for the right engine. For that to be the case, the first officer would have had to have forgotten his earlier actions of pulling back the power on the left (operational) engine and then the right (damaged) engine to reduce airspeed.
The National Transportation Safety Board (NTSB) considered whether the first officer’s use of prescription medications played a role in (1) forgetting his and the captain’s initial correct diagnosis and his movement of the left thrust lever (along with the right thrust lever) to reduce airspeed and (2) asserting erroneously that the left engine was the affected engine. The NTSB's analysis of the potential side effects of these medications found that the use of these medications likely did not play a role in the accident.
The NTSB also considered whether the first officer’s errors were due to fatigue. Even though the errors that the first officer made were consistent with the effects of fatigue, the evidence supporting fatigue was inconclusive. Stress is also known to degrade cognitive functions such as working memory, attention, and reasoning, and it provides an alternate explanation for the first officer’s actions. The loss of right engine thrust at a low altitude over the ocean at night was a surprising and stressful event, especially for the first officer as the pilot flying at the time of the engine event.
The captain initially questioned the first officer’s assessment, stating “number one is gone?”, but then accepted the assessment and stated, “so we have number two.” At that time, no salient cue was available to indicate which engine was affected (due to the reduced thrust on both engines and the lack of adverse yaw). During a postaccident interview, the captain remembered his initial assessment that the right engine was affected but stated that he had assumed that the first officer had a better understanding of the engines’ status because he was flying the airplane when the captain was communicating the emergency to ATC.
The captain had confidence in the first officer’s assessment of the affected engine based on their flight experience together; during a postaccident interview, the captain stated that the first officer “never makes a mistake.” Nevertheless, the captain did not take any action to verify the first officer’s assessment about the left engine, such as advancing the thrust lever for the left engine to determine whether an increase in thrust occurred. The operator’s simulator guide stated that pilots should be alert for changes indicating that thrust was being reduced on the incorrect (operational) engine. However, the crew did not notice the reduction in adverse yaw that resulted from the first officer’s reduction of thrust on the left engine. Subsequently, the reductions in thrust on the left and right engines (which the first officer made to reduce airspeed) meant that there would be no noticeable indications that would have reinforced the idea to the crewmembers that the left engine was affected, as they determined initially.
If the captain had thought to test the thrust on the left engine by advancing the left thrust lever, the flight crew would likely have noticed an increase in left engine thrust, a yaw to the right, and engine sounds indicating that the left engine was capable of producing normal power. The captain could also have simultaneously advanced both thrust levers and observed the left engine producing more thrust. However, neither flight crewmember suggested that the captain perform these actions, and neither of these potential diagnostic steps was included in the operator’s Engine Failure or Shutdown checklist.
Further, the Engine Failure and Shutdown checklist would not have helped the captain sort out the situation because the checklist appeared to assume that the airplane would be experiencing ongoing asymmetric thrust, which was not the case at this point in the accident flight. The checklist did not consider the possibility that a flight crew would need to delay checklist execution until after completing steps in an operator’s single-engine departure procedure, such as leveling off at a low altitude and reducing thrust on both engines. Because there was no longer a clear sign of which engine had failed and the crew had forgotten its earlier determination that the right engine had lost power, critical thinking was required for the crew to devise diagnostic steps to confirm the affected engine. However, each pilot’s thinking was degraded by high workload and stress.
The operator’s simulator guide stated that, for a single-engine failure after V1, “the Captain, if not currently the PM [pilot monitoring], may (and most times should) elect to become the PM and run the…checklist.” Remaining in the pilot monitoring role (which was recommended but not required) would have preserved more of the captain’s mental resources to correctly diagnose and respond to the engine issue. The captain’s decision to assume the pilot flying role before reconfirming the engine issue increased his workload and decreased his ability to perceive and evaluate key information, such as the positioning of the thrust levers, the performance of the engines, and changes in the airplane’s energy state. Thus, the captain’s decision to take control of the airplane also decreased his ability to manage the crew’s response to the abnormal situation.
In addition, the captain’s lack of awareness of the left engine’s low commanded thrust level, along with the subsequent deterioration of the airplane’s energy state throughout the rest of the flight, played a role in his (1) failure to verify the first officer’s (incorrect) assertion about the left engine and (2) inability to detect the crew’s misidentification of the affected engine and cognitively reframe the situation. The NTSB considered whether fatigue played a role in the captain’s errors, but the evidence was inconclusive. These errors were likely the result of the captain’s high workload and stress. Research indicates that, under conditions of high workload and stress, “crews are vulnerable to missing important cues related to their situation and are likely to experience difficulty pulling together disparate pieces of information and making sense of them,” especially when “some of that information is incomplete, ambiguous, or contradictory.” (Burian, B.K., Barshi, I., and Dismukes, K., 2005).
The captain’s high workload increased further due to his decision to continue handling ATC radio communications, which occurred frequently on an ongoing basis throughout the flight. It is possible that the captain decided to maintain control of the radios based on information that he learned during the operator’s crew resource management (CRM) training. Specifically, the operator’s initial CRM training included a video that presented the circumstances of the September 2007 accident involving American Airlines flight 1400, including the distraction that radio communications caused the pilot monitoring while he attempted to execute the appropriate abnormal checklist. Thus, the captain of the Transair accident airplane might have thought that, by relieving the first officer of the responsibility of handling the radios, the first officer could focus his attention on performing the Engine Failure or Shutdown checklist (which is further discussed in the next section).
The captain’s ability to properly respond to the emergency was further diminished toward the end of the flight when he thought that the airplane could have a dual-engine failure, as demonstrated by his transmissions to the controller stating, “we might lose the other engine too” and, 2 minutes 19 seconds later, “there's a chance we're gonna lose the other engine too.” After the crewmembers noticed that the right engine was overheating, their attention became primarily focused on monitoring basic flight instruments and controlling the airplane. The crew’s communications and behavior during this latter portion of the flight were consistent with stress-related attentional narrowing, which restricts a person’s perceptions to the most salient cues and results in rigid thinking by reducing the number of alternatives that are considered (Stokes, A., and Kite, K.,1994). Attentional narrowing diminished the crew’s ability to understand and control the abnormal situation. As a result, the flight crew became fixated on monitoring the right EGT as well as basic flight parameters while manipulating only the right engine thrust lever.
Checklist Performance
The captain was aware that numerous steps in the operator’s Boeing 737-200 Engine Failure or Shutdown checklist were expected to be performed before the airplane could return to the airport. The previous criticism that the captain received from the company’s chief pilot for his handling of an earlier in-flight emergency (during which he returned to the airport without completing a required checklist) likely added pressure to the already-demanding situation of troubleshooting an engine issue while flying at a low altitude over the ocean at night.
The Engine Failure or Shutdown checklist defined three conditions that warranted the use of that checklist: an engine failure, an engine flameout, or another checklist that directed an engine shutdown. The checklist had 11 reference items, none of which were memory items. The Engine Failure or Shutdown checklist required pilots to confirm that the thrust lever for the affected engine was selected, move that thrust lever to the idle position, and shut down the corresponding engine. However, the checklist was not designed to help the crew identify the affected engine. Further, the operator’s simulator guide stated that the primary indications of an engine failure were a yawing moment and the rudder input required to counteract it, but neither was present at the time that the checklist was initiated. Thus, the simulator guidance did not reflect realistic operational conditions because it did not account for the possibility of a partial loss of thrust or a possible need to level off and reduce thrust on both engines before completing the checklist.
The captain called for the Engine Failure or Shutdown checklist about 4 minutes 26 seconds after the first indication of an engine problem. The captain’s communications with ATC after the onset of the emergency (as well as the need to assist the first officer in executing various aspects of the single-engine departure procedure) distracted the captain and precluded him from calling for the checklist sooner. The operator does not require its pilots to conduct the checklist immediately after an engine issue is detected. However, if the checklist had been started earlier in the accident sequence (that is, when adverse yaw was occurring or the EPR indications clearly showed which engine was producing lower thrust), and if fewer intervening distractions had occurred, the first officer might have recalled that he had reduced engine thrust to decrease the airplane’s speed, and both crewmembers might have recalled their initial (correct) diagnosis of the affected engine.
The first officer stated that he had accomplished “maybe a third or less” of the checklist, but the CVR showed that he had only read aloud the conditions for performing the checklist. The first officer further stated that he stopped the checklist (for the first time) because of the high EGT on the right engine (which he described as “beyond max”). Afterward, the captain stated that they should head toward the airport, which the first officer suggested about 1 minute earlier (before he started reading aloud the conditions for performing the checklist). The captain then asked the first officer to set up the instrument landing system approach, and the captain contacted the controller to let her know that the airplane was ready to return.
About 1 minute 35 seconds after the first officer informed the captain about the high EGT on the right engine, the captain instructed the first officer to “see what you can do in the checklist finish as much as possible.” About 15 seconds later, the first officer resumed reading aloud the conditions for performing the checklist but then stopped (for the second time) to state “we have to fly the airplane though” because the airplane was “slowing” or “low” and he thought that the captain was not focused on flying the airplane. Although the first officer likely thought that it was appropriate to focus on resolving the symptoms of the abnormal situation (the high EGT on the right engine and the airplane’s decreasing energy state) instead of performing the checklist, the first officer’s comments caused the crew’s attention to be directed away from confirming which engine was affected.
After the first officer advised the captain to focus on flying the airplane, the captain stated “okay” and did not redirect the first officer to continue the checklist. During a postaccident interview, the captain stated that, when he saw that the EPR for the right engine was decreasing and that there was “nothing coming out” of the left engine, he thought that performing the checklist would be “useless” because both engines had “already shut themselves down.” It is possible that performing the checklist’s third item, “AFFECTED ENGINE…CONFIRM…CLOSE” might have prompted the crew to shut down the incorrect (left) engine, which would not have prevented this accident. However, it is also possible that performing this checklist item might have led the crew to reconsider the source of the engine issue and the correct cause of the airplane’s deteriorating energy state. Thus, as a result of the flight crewmembers’ stress-related attention tunneling (which led to their thinking that a dual-engine failure was occurring and fixation on the right EGT and basic flight parameters), they neglected to perform a checklist item that might have alerted them about their misidentification of the affected engine.
The operator’s CRM training emphasized the importance of using checklists to manage abnormal situations and defend against error. During the accident flight, the captain and the first officer demonstrated ineffective CRM. Specifically, the captain did not ensure that the first officer, after his interjections while reading the conditions of the Engine Failure or Shutdown checklist, continued performing the checklist so that the affected engine could be confirmed. In addition, the captain demonstrated difficulties with task prioritization (an aspect of workload management) and leadership because, as pilot-in-command, he did not ensure that the checklist was accomplished, and he was distracted by lower-priority tasks, such as communicating with ATC. As a result, the flight crew was unable to coordinate an effective response to the emergency situation.
Emergency Response
The controller contacted the USCG Joint Rescue Coordination Center, which was responsible for coordinating US search and rescue activities in the Pacific Ocean, to report that the accident airplane was in the water. An aircraft rescue and firefighting (ARFF) rescue boat and a USCG helicopter from Barbers Point Air Station launched about 0200 and 0218, respectively.
The USCG helicopter arrived on scene about 0230 and located the accident airplane and crew. The captain was hanging onto the floating tail section of the airplane, and the first officer was on top of floating debris. The captain was struggling to stay afloat after the tail began to sink, and he was hoisted from the water to the helicopter with the assistance of a rescue diver. The diver then re-entered the water and swam with the first officer to the ARFF rescue boat, which had arrived on scene about 0240. The first officer received medical care once aboard the rescue boat.
The helicopter transported the captain directly to a local hospital. The rescue boat encountered high surf and low visibility while traveling back to the ARFF station, arriving about 0406. The first officer was then taken to the hospital; his delayed arrival there did not affect the treatment of his injuries, which were minor. Thus, the search and rescue operation was timely and effective.
Survival Factors
The captain and the first officer were wearing their restraints, including their shoulder harnesses, at the time of the accident. According to the first officer, his upper torso moved forward during impact, and his right shoulder rolled forward, downward, and to the left, which caused his body to twist so that he was facing to the left. The first officer’s head then moved downward, and the top of his head struck something in front of him, resulting in a minor head injury that did not impede his evacuation from the airplane.
Postaccident examination of the first officer’s seat found that the seatback had collapsed. Subsequent examination by the NTSB’s Materials Laboratory determined that the seatback collapse was due to the fracture of a jack nut that was part of a jackscrew assembly. The jack nut fractured in overstress due to loads that exceeded its load-bearing capacity.
The accident airplane model was certificated in December 1967, and the first officer’s seat was manufactured in September 1984. The seat complied with Technical Standard Order (TSO)-C39A, which was issued in February 1972. The TSO required the seat to meet a static load requirement of 9 G forward and 6 G downward. The loads that the first officer’s seat sustained during the ditching could not be determined from the available evidence for this investigation.
Newer seating systems are required to meet higher loads during certification. Specifically, crewmembers and passenger seating systems certificated under Title 14 Code of Federal Regulations Part 25 must currently meet, among other criteria, a dynamic requirement of 16 G forward and 14 G downward. These dynamic requirements apply to newly designed airplanes certificated after 1988 and all Part 25 airplanes manufactured after 2009, except for those that do not carry passengers for hire (including cargo-only airplanes, such as the accident airplane). According to the Federal Aviation Administration (FAA), four cargo 737-200 airplanes were registered in the United States as of November 2022, but the available evidence for this investigation did not indicate whether those airplanes were in active use.
- Probable Cause: The flight crewmembers’ misidentification of the damaged engine (after leveling off the airplane and reducing thrust) and their use of only the damaged engine for thrust during the remainder of the flight, resulting in an unintentional descent and forced ditching in the Pacific Ocean. Contributing to the accident were the flight crew’s ineffective crew resource management, high workload, and stress.
- Report:
- Docket:
NTSB Docket - Docket Management System
There was a lot of holes in that swiss cheese!
CoffeeIcePapers
Well-Hung Member
Yikes
Boris Badenov
Fortis Leader
Hmm. Guess we should just expect a certain number of parts to fall out every once in a while.
BEEF SUPREME
Well-Known Member
It’s called the pilots airplane for a reason…
Sent from my iPhone using Tapatalk
NovemberEcho
Dergs favorite member
Is it hard to identify which engine dies on airliners? I feel like the remaining engine is the one brought to idle way too often.
Wardogg
Meat Popsicle
Me thinks someone needs to learn 2 borescope.
I assume this was on some engine program. Were they just pencil whipping the inspections?
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No. The FO identified the correct engine initially, but then either forgot or got distracted, and the correct engine got mis-identified.
This particular bird had very old school JT8D-9s on it. We were running -15 versions of the same engine, and during a removal for inspection of one of them that was regularly running hotter than the other, found all kinds of worn blades deep down. And the -15s were considered old engines, never mind the -9s.
arkflyr
Well-Known Member
Rhoades doesn't believe in engine programs, they just send it.
Back when I was at ACT flying MU-2s we had an ex-Rhoades pilot, he described that place as so bad it made us look like United. And he himself was a truly feral freight dog, lived in an RV with his Filipino wife, his type ratings were in the L-188 and the CV240/340/440, and what ever the turbine versions were as he had flown both.
KLB
Well-Known Member
Even still. I have to go back and re-read. But the good engine was still running right? They never shut it down and secured it. With that being said, would you rather go down with one "good" (we know that misidentified which engine was good) engine or would you rather keep it flying with one could engine and one bad engine? If the "bad" engine is running and not secured...I'm using it along with the good engine until it quits if it comes to me maintaining level flight or going down.
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Yeah, they never finished the checklist, or really got it started for that matter.
Fly both throttles until it can be reconfirmed which one is bad, and I agree….if the bad engine is producing some thrust, that’s better than nothing.
Bad part is the Capt wanted to do an immediate return, which I agree with, but had been chastised by training officer for having done so last time and come right back around for a landing without having completed all checklists. Had that chastise not occurred, the Capt likely would’ve elected to simply enter a wide downwind and take the visual approach that ATC had cleared him for and successfully landed. Rather than drive out to sea for no reason other than to accomplish a checklist.
CoffeeIcePapers
Well-Hung Member
That’s a problem in the 121 world for sure.
Cherokee_Cruiser
Bronteroc
Cherokee_Cruiser
Bronteroc
SurferLucas
Southern Gentleman
I’m going to Flaps 2 even harder now
Roger Roger
Bottom of the list
The people going “SEE 121 DOES DUMB THINGS TOO” are the ones who’d post on social media about how their uncle only survived because he wasn’t wearing a seatbelt and was thrown clear of the wreck