HeyEng
Well-Known Member
We deployed it on the C-5 during flight test. I recall that they are pretty noisy inside the airplane but couldn't tell you if it was that loud outside or if you could hear it over the engines.
Air India plane crash
- Thread starter ASpilot2be
- Start date
I can only imagine what it was like in the early days of the EFB what was found when some of the oldsters started retiring!
ChasenSFO
hen teaser
The fact they even have to tell you that...
CoffeeIcePapers
Well-Hung Member
At my regional, they told us "we know that you kill hookers and don't care. Unless you kill them on a layover in your hotel room, in which case, we will turn you in."
Cherokee_Cruiser
Bronteroc
What happened had nothing to do with any avoiding of any urban area. This airplane was nose up and increasing more nose up as it fell. No way did they see what they hit at the end.
Pilot Fighter
Well-Known Member
At a certain point, we need to break out our wallets. If I were handicapping this horse race, I would box A and B for the Exacta.
A. Bonehead piloting
B. Bonehead piloting + survivable MX
C. Unsurvivable MX
Cherokee_Cruiser
Bronteroc
I have a feeling if it was C, we would have heard by now. Just a guess. Time will tell.
Skåning
Well-Known Member
Pilots are the dumbest smart people…
///AMG
Well-Known Member
Someone already knows (i.e. someone in Boeing PNW). You're probably right, it would have leaked onto SM by now if there were anything significant. Not exactly proof, but I'd be pretty surprised if someone didn't blab onto FB/reddit/whatever......they sure did (across both parties) in the immediate aftermath of 1282.
BEEF SUPREME
Well-Known Member
I'm sure someone has plugged the FDR into a computer already and a bunch of people are watching an animation of the entire flight. With little hand icons that move all the controls.
It's just a matter of time now....
It's just a matter of time now....
Air India latest: Black box to be sent to US for analysis after ‘heavy damage’
Indian aviation regulator finds no major safety flaws in Air India Dreamliners but flags maintenance and coordination issues
www.independent.co.uk
Boris Badenov
Fortis Leader
"MX delays and coordination issues" but nothing grounded sure makes it sound like deferred or just unperformed maintenance, and "emergency power" certainly sounds like the RAT did deploy. But what sort of mx screwup would cause both engines to fail at exactly the same time? The nose didn't even wiggle, AFAICT.
Cherokee_Cruiser
Bronteroc
I’m still leaning towards some automation mismanagement leading to thrust rolling back to idle, construed as double engine failure and some sort of memory items started that included deploying a RAT.
Nishmaster
Well-Known Member
Per reports today, no data has been extracted from the the FDR yet, so the talk of it being impossible to be an equipment failure (due to planes not being grounded or other actions taken) may be, unfortunately, premature. Reportedly it is being shipped to the NTSB, due to the facility in India being unable to read the unit with the current level of external physical damage.
Murdoughnut
Well sized member
One of the few educated ideas I've seen put out there:
Posted by @HeyFixThis on youtube
"I believe the cause was a combination of Fuel Shutoff Valve (FSOV) activation due to an cascading electrical system failure. It’s not the first time a 787 has experienced electrical cascade system failure during the first minutes in flight and required RAT deployment. Let me explain my reasoning:
On the Boeing 787, the engines will keep running even if all hydraulic systems fail. Each engine has its own FADEC (Full Authority Digital Engine Control), powered by a Permanent Magnet Alternator (PMA) that’s driven by the engine itself. Once the engine is spinning, the FADEC operates independently — controlling fuel, thrust, and safety — with no need for aircraft hydraulics or external electrical power. A simultaneous FADEC failure is extremely unlikely.
So, why did the engines shut down if they are supposed to be so resilient? There is one important component that can override the FADEC: the FSOV. This spring-loaded fuel shutoff valve is not powered by the PMA, but instead by the aircraft's electrical DC system. If power is lost, the spring closes the valve instantly, cutting off fuel to the engine. FSOVs are a fail-safe, designed to protect the airframe, not the engine. In Boeing’s logic, it's safer for the engine to shut down than to keep feeding fuel into a potential fire.
In the video footage, the truck tilt actuator is in the forward position (toes down). This movement requires a hydraulic system force to overcome the wind and gravity. This forward position only happens when the landing gear retracted sequence is initiated by the pilots.
The strange thing is that it is only the second step of the main gear retraction sequence to tilt the wheel truck forward. The first step is to open the doors, and if the doors are fully open, the next step is to tilt the wheel truck. It’s unclear why the doors are closed but the truck already tilted forward.
Most likely the pilot selected “gear up,” which triggered the retraction sequence. The truck tilt was initiated as step 2, but the doors didn’t open due to power or hydraulic failure, or the sequence froze mid-process. The aircraft lost main power (hence the RAT), and the sequence halted with the gear in a partially commanded state: truck tilted, doors closed, gear extended.
That gear retraction moment may have been the exact point when the whole system collapsed just 3-4 seconds after takeoff.(there was a positive climb rate at 600ft AMSL and 174kt ) The engines kept running briefly (3seconds), powered by the remaining fuel in the lines before flaming out.
The main landing gear hydraulics are powered by an electric-hydraulic system — if there’s no electricity, there’s no hydraulic pressure. In contrast, other hydraulic systems on the aircraft are supplied by engine-driven mechanical pumps. (20-30kw power needed to retract gear)
Since the aircraft remained stable in flight, it's likely that both engines flamed out simultaneously. Flaps, fly-by-wire, landing gear, and other systems likely froze for a moment and possibly regained functionality after the RAT deployed. The +-15kW RAT powers the electric motors on the blue hydraulic lines of a 787. This controls the key flight-control actuators for the rudder, elevators, and primary ailerons. It appears that the pilot slightly increased the nose attitude during the final phase of the flight. (landing gear retraction is not possible with a RAT)
For both FSOVs to close, the aircraft would have to lose both AC buses, both DC essential buses, and the battery backups. That requires a massive electrical failure to overcome all possible redundancy layers. This is a possibility because there are known cases where a 787 and a 777 experienced a total electrical cascading failure of most systems. So it is possible.
All signs point to fuel cutoff via the FSOVs. The big question is why did they fail? This is hard to say but as said electrical failure is a very plausible cause.
The RAT was automatically deployed. This means there is a total loss of AC electrical power.
I suspect a scenario where a partially working or unstable electrical system triggers RAT deployment amid a power transition event. This could escalate into a full-blown electrical disruption, possibly interfering with the DC essential buses and battery backup. When switching power sources (from main buses to RAT), the system can behave unpredictably — especially if one source is competing with the RAT or is unstable.
In such a power chaos, RAT deployment might introduce transients or delays in power restoration, which could make power delivery unstable and possibly affect the digital managed power to the FSOVs. If they lose power, all fuel will be cut off.
On the 787, FSOVs don’t have guaranteed dedicated or hot battery backup, unlike the Airbus A320, which powers them directly from the battery. The 787’s battery backup supports the entire DC bus, and power management software prioritizes flight-critical systems. If power is limited or loads are erratic, less critical systems like FSOVs can be deprioritized. This is a very complex system with a lot of software rules.
This also reflects Boeing's design philosophy: in a severe power failure, airframe survivability and flight control take precedence over engine continuity. Their assumption is that it’s safer to shut off fuel than risk uncontrolled flow in to an engine on fire.
The whole idea of the posibility of losing both engines at 400 ft during takeoff feels inherently unsafe. From a thrust continuity perspective, this design approach is a vulnerability and may have played a role in Flight AI171’s dual-engine flameout.
To date, there are no documented cases of a modern Boeing experiencing a engine flameout from FSOV closure due to an electrical glitch. The 787 and other Boeing models have a history of similar electrical issues.
In 2024 an Atlantic Boeing 787 flight, VS105 during climb-out, the crew experienced a major electrical failure— engine generators dropped off-line. In response, the RAT automatically deployed to provide emergency power.
In 2015, Boeing and the FAA discovered a critical software bug in the 787’s Generator Control Units (GCUs). If left powered for 248 consecutive days, an internal counter could overflow — shutting down all four GCUs and cutting AC power entirely. The FAA issued Emergency AD 2015-08-51, requiring operators to reboot 787s every 8 months to avoid in-flight total power loss.
Two separate incidents—in Boston (JAL) and Takomatsu (ANA)—involved battery overheating and fire in the aircraft’s APU lithium-ion batteries
In December 2018, LATAM Flight LA8084, a Boeing 777-300ER, suffered a complete electrical meltdown en route from São Paulo to London. The RAT deployed to provide emergency power. Once the engines were shut down on the ground, power suddenly returned — confirming a fault in the electrical distribution system (likely a bus contactor or converter failure). The event was a textbook cascading failure: generator power was available, but a chain reaction of breaker and converter failures disconnected all major buses, including those powered by the APU and engines.
The 787 relies heavily on software-based power management, so if the root cause turns out to be a software flaw in a extremely complex electrical system, the entire fleet could soon be grounded pending investigation.
Posted by @HeyFixThis on youtube
"I believe the cause was a combination of Fuel Shutoff Valve (FSOV) activation due to an cascading electrical system failure. It’s not the first time a 787 has experienced electrical cascade system failure during the first minutes in flight and required RAT deployment. Let me explain my reasoning:
On the Boeing 787, the engines will keep running even if all hydraulic systems fail. Each engine has its own FADEC (Full Authority Digital Engine Control), powered by a Permanent Magnet Alternator (PMA) that’s driven by the engine itself. Once the engine is spinning, the FADEC operates independently — controlling fuel, thrust, and safety — with no need for aircraft hydraulics or external electrical power. A simultaneous FADEC failure is extremely unlikely.
So, why did the engines shut down if they are supposed to be so resilient? There is one important component that can override the FADEC: the FSOV. This spring-loaded fuel shutoff valve is not powered by the PMA, but instead by the aircraft's electrical DC system. If power is lost, the spring closes the valve instantly, cutting off fuel to the engine. FSOVs are a fail-safe, designed to protect the airframe, not the engine. In Boeing’s logic, it's safer for the engine to shut down than to keep feeding fuel into a potential fire.
In the video footage, the truck tilt actuator is in the forward position (toes down). This movement requires a hydraulic system force to overcome the wind and gravity. This forward position only happens when the landing gear retracted sequence is initiated by the pilots.
The strange thing is that it is only the second step of the main gear retraction sequence to tilt the wheel truck forward. The first step is to open the doors, and if the doors are fully open, the next step is to tilt the wheel truck. It’s unclear why the doors are closed but the truck already tilted forward.
Most likely the pilot selected “gear up,” which triggered the retraction sequence. The truck tilt was initiated as step 2, but the doors didn’t open due to power or hydraulic failure, or the sequence froze mid-process. The aircraft lost main power (hence the RAT), and the sequence halted with the gear in a partially commanded state: truck tilted, doors closed, gear extended.
That gear retraction moment may have been the exact point when the whole system collapsed just 3-4 seconds after takeoff.(there was a positive climb rate at 600ft AMSL and 174kt ) The engines kept running briefly (3seconds), powered by the remaining fuel in the lines before flaming out.
The main landing gear hydraulics are powered by an electric-hydraulic system — if there’s no electricity, there’s no hydraulic pressure. In contrast, other hydraulic systems on the aircraft are supplied by engine-driven mechanical pumps. (20-30kw power needed to retract gear)
Since the aircraft remained stable in flight, it's likely that both engines flamed out simultaneously. Flaps, fly-by-wire, landing gear, and other systems likely froze for a moment and possibly regained functionality after the RAT deployed. The +-15kW RAT powers the electric motors on the blue hydraulic lines of a 787. This controls the key flight-control actuators for the rudder, elevators, and primary ailerons. It appears that the pilot slightly increased the nose attitude during the final phase of the flight. (landing gear retraction is not possible with a RAT)
For both FSOVs to close, the aircraft would have to lose both AC buses, both DC essential buses, and the battery backups. That requires a massive electrical failure to overcome all possible redundancy layers. This is a possibility because there are known cases where a 787 and a 777 experienced a total electrical cascading failure of most systems. So it is possible.
All signs point to fuel cutoff via the FSOVs. The big question is why did they fail? This is hard to say but as said electrical failure is a very plausible cause.
The RAT was automatically deployed. This means there is a total loss of AC electrical power.
I suspect a scenario where a partially working or unstable electrical system triggers RAT deployment amid a power transition event. This could escalate into a full-blown electrical disruption, possibly interfering with the DC essential buses and battery backup. When switching power sources (from main buses to RAT), the system can behave unpredictably — especially if one source is competing with the RAT or is unstable.
In such a power chaos, RAT deployment might introduce transients or delays in power restoration, which could make power delivery unstable and possibly affect the digital managed power to the FSOVs. If they lose power, all fuel will be cut off.
On the 787, FSOVs don’t have guaranteed dedicated or hot battery backup, unlike the Airbus A320, which powers them directly from the battery. The 787’s battery backup supports the entire DC bus, and power management software prioritizes flight-critical systems. If power is limited or loads are erratic, less critical systems like FSOVs can be deprioritized. This is a very complex system with a lot of software rules.
This also reflects Boeing's design philosophy: in a severe power failure, airframe survivability and flight control take precedence over engine continuity. Their assumption is that it’s safer to shut off fuel than risk uncontrolled flow in to an engine on fire.
The whole idea of the posibility of losing both engines at 400 ft during takeoff feels inherently unsafe. From a thrust continuity perspective, this design approach is a vulnerability and may have played a role in Flight AI171’s dual-engine flameout.
To date, there are no documented cases of a modern Boeing experiencing a engine flameout from FSOV closure due to an electrical glitch. The 787 and other Boeing models have a history of similar electrical issues.
In 2024 an Atlantic Boeing 787 flight, VS105 during climb-out, the crew experienced a major electrical failure— engine generators dropped off-line. In response, the RAT automatically deployed to provide emergency power.
In 2015, Boeing and the FAA discovered a critical software bug in the 787’s Generator Control Units (GCUs). If left powered for 248 consecutive days, an internal counter could overflow — shutting down all four GCUs and cutting AC power entirely. The FAA issued Emergency AD 2015-08-51, requiring operators to reboot 787s every 8 months to avoid in-flight total power loss.
Two separate incidents—in Boston (JAL) and Takomatsu (ANA)—involved battery overheating and fire in the aircraft’s APU lithium-ion batteries
In December 2018, LATAM Flight LA8084, a Boeing 777-300ER, suffered a complete electrical meltdown en route from São Paulo to London. The RAT deployed to provide emergency power. Once the engines were shut down on the ground, power suddenly returned — confirming a fault in the electrical distribution system (likely a bus contactor or converter failure). The event was a textbook cascading failure: generator power was available, but a chain reaction of breaker and converter failures disconnected all major buses, including those powered by the APU and engines.
The 787 relies heavily on software-based power management, so if the root cause turns out to be a software flaw in a extremely complex electrical system, the entire fleet could soon be grounded pending investigation.