E28 HOOK--re: Key West NAS

[RICHARD5]

Please shed some light on how the hook system works. On Google Earth I didn't see any shadows (indirect evidence of absence of structure) for any arresting gear. What I saw on Google Earth looked like painted runway markings about 1,500' fromt he thresholds. Would these be alignment marks for temporary arresting gear and aiming points for aircrew? I confess to zero knowlege yet 100% curiosity.

 

[JDean3204]

I made a few trips as a maintainer to key west for the sole reason of FCLP's. I am pretty sure they actually have functioning arresting gear at KNQX ( obviously need to be rigged prior to any situation needed). I was stationed at KNGU and I know they had arresting gear there, I witnessed them actually use it twice. They would notify field ops and could rig it within 20 minutes for a recovery. KNQX was a well known spot to conduct FCLP's because of the markings on the field, they also have several indications on the field that replicate carrier landings ( not sure if they had an ACLS transmitter or not). I never complained about going there as Duval Street was a good place to burn our per diem!!

here is an Airnav link that states what RW's and distance from TH those wires will be rigged if needed.

http://www.airnav.com/airport/KNQX

 

[RICHARD5]

JDean, thanks. Your mention of Field Carrier Landing Practice got me curious. So back to Google Earth to look at Lemoore NAS (KNLC) where once when VFR transiting the area I did listen to and watch a recovery of a flamed out Hornet with live ord. Anyway, I see NLC has the same runway markings as NQX. I also noticed the NLC has what appears to be FCLP markings painted on the rwy in addition to the E28 markings.

I remain curious but ignorant of the E28 markings.

BTW: I would love to do a break at 70 AOB at 300 kts but that's a different subject.

 

[///AMG]

I was just down at key west flying for a couple weeks, and yes, they have both short field (approach end) and long field (departure end) E-28 gear at all corners of the field. I can't remember if they had the duty runway short field gear de-rigged for non-Hornet departures, but either way, the stuff is there at both ends of all three runways. Navy fields have a big lighted sign, similar to the ft remaining markers, that has just a big yellow circle on it, directly next to the gear on either side.

 

[RICHARD5]

Thanks, AMG. I guess my questions boils down to the painted markings specifically. What is the purpose of the markings? The markings extend across the rwy and feature a solid black line overlaid by a series of yellow circles of approx 8' diameter. The markings are approx 1,500' from the threshold. Actually the airport diagram for NQX (as shown on AirNav) show most markings are 1,500' but in some cases are as short as 1,135'.

 

[BobDDuck]

That's where the cable goes. Many military airfields have them rigged and across the runway at all times. They are raised slightly by what looks like big Rollerblade wheels every few feet along the cable. They are safe to taxi and land over (we do all the time in the CRJ at Eglin). My understanding is that some jet like the F16 have an emergency hook that they can pneumatically deploy in the event of a break failure or high speed reject and catch the departure end cable.

 

[MikeD]

Most military and joint-use runways have two separate aircraft stopping systems: arresting gear, and aircraft barriers.

Arresting gear is designed to be engaged by tailhook-equipped aircraft and consists of a wire strung across the runway at various points and either supported by rubber "donuts" designed to keep the wire about 2 inches above the runway surface (that's the case with BAK-6/9/12 and 13 or E-27/E-28 at USN/USMC bases), or recessed in a slot on the runway and raised by remote control by the tower controller as needed (BAK-14). When engaged by an aircraft, the wires run out and are connected at each end to a box on both sides of the runway that contains the stopping mechanism. The stopping mechanism consists of brake pads on a caliper that engage a rotor at a certain rate, stopping the aircraft; or a hydraulic "water squeezer" (on BAK-6) that engages a piston pushing against water inside a tube for "hydraulic" stopping ability. On the airport diagram, the arresting gear is depicted as a one-or two-way arrows near the approach, center, and/or departure ends of the runway. One-way arrows indicate single-direction arrestment, two-way arrows indicate bi-directional arrestment ability. To see on an actual runway where these systems are located, they're marked by painted yellow circles across the runway at the cable location, as well as a lighted sign abeam each side of the system which is a lighted yellow circle on a black background, in normal airport-signage presentation.

Aircraft barriers are located at the departure ends of the runway and are designed to either "catch" the aircraft's wings, or it's main landing gear. Older systems, such as the MA-1A, consist of a approximately 6 inch high wire hooked to a 2-foot recessed net that lays flat on the runway. As the aircraft passes into the overrun, it's nosewheel runs over the 6-inch high wire causing the 2 foot high net to spring-up and engage the main landing gear of the aircraft, bringing it to a stop in the overrun. Newer barriers, such as the BAK-15/61IISQ, are raised by remote control from the tower and consist of a 23 foot high net supported by stanchions on each side of the runway, similiar to those emergency barriers aboard aircraft carriers, that catch the aircraft's wings as the aircraft passes through it, and stops the aircraft in the overrun. On the airport diagram, the barriers are depicted as a "vvvv" looking symbol at the end of the runway.

Some military aircraft, such as the F-4, F-117, B-52, and some foreign versions of the F-16, still utilize drag chutes that are deployed on landing in order to shorten landing roll in normal ops, and as an abort aid for takeoff emergencies.

 

[RICHARD5]

Dyno-mite! Mike, thank you for the time to type that up. Thank you too BobD.

I suspect the primary purpose of the painted markings are visual aids for the inbound aircrew. However, this leads to an add-on question. If my suspicions are correct about the purpose of the markings, does that mean there are special tasks operationally or procedurally for the aircrew for an emergency recovery? I mean, there are already the usual rwy markings and signage. Why the "extra" markings? (yellow circles)

 

[MikeD]

I suspect the primary purpose of the painted markings are visual aids for the inbound aircrew. However, this leads to an add-on question. If my suspicions are correct about the purpose of the markings, does that mean there are special tasks operationally or procedurally for the aircrew for an emergency recovery? I mean, there are already the usual rwy markings and signage. Why the "extra" markings? (yellow circles)

It's just so they can stand out. So the edge signs don't get lost amongst the distance remaining signs. Special procedures are for those using the equipment is to land prior to them and engage them as close to center as possible. Additionally, for approach end gear thats in battery, many aircraft that don't use the arresting gear.....some aircraft with gear doors or low sitting aircraft, often civilian....will try to land beyond the approach end gear in order that they don't have to run over the wire while still high speed (N/A with a BAK-14 system).

 

[RICHARD5]

I hadn't thought some aircraft types may want to land beyond the gear. Would tis be the long field gear AMG mentioned?

FYI: The recovery at NLC I listened to was quite curious. Aside from the fact that they communicated on VHF, I thought it interesting that intially tower asked the pilot if he wanted "the net". Pilot responded in the negative. At that point a different, more authoritive voice came on freq to pretty much command the pilot that yes, the net will be deployed. That voice, who I thought to be a TWR supervisor, reiterated the live ord condition.

I held the impression that recovery is in the realm of ground ops/CFR and aircrew is not part of the decision tree. Keep all informed and in the loop, yes, but aircrew is not in a command role at that point.

 

[BobDDuck]

I hadn't thought some aircraft types may want to land beyond the gear. Would tis be the long field gear AMG mentioned?

We try to land past it in the RJ, and exit the runway before the departure end cable. They are fine to run over but they make a REALLY loud thumping noise when you do and it tends startle the passengers. Mostly our instructions from tower are "line up and wait, runway XX. Taxi past the cable approved." And, we normally have data for Runway XX CBL-CBL.

 

[dasleben]

We try to land past it in the RJ, and exit the runway before the departure end cable. They are fine to run over but they make a REALLY loud thumping noise when you do and it tends startle the passengers. Mostly our instructions from tower are "line up and wait, runway XX. Taxi past the cable approved." And, we normally have data for Runway XX CBL-CBL.

Yeah, we even try to not land on the cable in the 76, though sometimes it can't be avoided. The airplane isn't particularly graceful on touchdown normally, so hitting the 3 wire with the gear makes it even less so.

Takeoffs are just done over the wire; you can feel and hear the nose wheel go over it, but I haven't felt/heard anything with the mains.

 

[MikeD]

I hadn't thought some aircraft types may want to land beyond the gear. Would tis be the long field gear AMG mentioned?

No. It's the short field gear he's talking about. Long field is at the departure end.

Approach end of runway = Short Field gear (USN/USMC) / Approach End gear (USAF)
Departure end of runway = Long Field gear (USN/USMC) / Departure End gear (USAF)

FYI: The recovery at NLC I listened to was quite curious. Aside from the fact that they communicated on VHF, I thought it interesting that intially tower asked the pilot if he wanted "the net". Pilot responded in the negative. At that point a different, more authoritive voice came on freq to pretty much command the pilot that yes, the net will be deployed. That voice, who I thought to be a TWR supervisor, reiterated the live ord condition.

Depends what the SOP is for the particular emergency, for the particular airfield.

I held the impression that recovery is in the realm of ground ops/CFR and aircrew is not part of the decision tree. Keep all informed and in the loop, yes, but aircrew is not in a command role at that point.

Aircrew advises what they have and any special needs they may have. Response happens based on what they have/report.

 

[MikeD]

We try to land past it in the RJ, and exit the runway before the departure end cable. They are fine to run over but they make a REALLY loud thumping noise when you do and it tends startle the passengers. Mostly our instructions from tower are "line up and wait, runway XX. Taxi past the cable approved." And, we normally have data for Runway XX CBL-CBL.

Yes. 767 or RJ, running over the cable is no big deal; however as you say, it is a startling noise if you're not expecting it, such as a pax. Aircraft like an early Citation or something, or low sitting aircraft with ventral protrusions from the fuselage, generally try to avoid rolling over the cable at high speeds.

Alot of airfields, if you decide to taxi past the arresting gear, tower will give you the "....XXXX' remaining" if you're not familiar of how much runway there is past the gear.

 

[///AMG]

I hadn't thought some aircraft types may want to land beyond the gear. Would tis be the long field gear AMG mentioned?

FYI: The recovery at NLC I listened to was quite curious. Aside from the fact that they communicated on VHF, I thought it interesting that intially tower asked the pilot if he wanted "the net". Pilot responded in the negative. At that point a different, more authoritive voice came on freq to pretty much command the pilot that yes, the net will be deployed. That voice, who I thought to be a TWR supervisor, reiterated the live ord condition.

I held the impression that recovery is in the realm of ground ops/CFR and aircrew is not part of the decision tree. Keep all informed and in the loop, yes, but aircrew is not in a command role at that point.

I've never been to a Navy field where the tower has the authority to tell a pilot how to deal with an emergency. It could very well have been that someone else was on the freq as well, like a wingman/lead flying overhead or with the guy.....maybe the CO or something. In an emergency it is not uncommon for guys to switch up to their company/squadron base freq in the back/aux radio for troubleshooting and emergency procedure reading.....you only have so much brain power in a single seat jet when you are struggling to fly a broken aircraft, so it is extremely common for guys to get the help of a flight member or someone on the ground. That could have been part of what you heard. I've also never heard of anyone taking a "net" at the field, but maybe it is a Lemoore thing.....I've only flown there a couple of times before. That said, there isn't any procedure in the Hornet that calls for a barricade arrestment at the field (just at the boat).

 

[Nark]

I have some expertise in this realm.

As far as what goes on in the emergency, the "recovery team" would gather as much information as possible via ATC. Weight and engagement speed of the aircraft, any ordinance etc... They would ensure the gear is ready (in battery) and stand by.

The aircraft may either roll in, (land 100-500+Prior) and take the gear, or they may chose to fly-in (utilize the FLOLS or other optical guidance, much like a PAPI)
The E28 is fat ,dumb and happy. It doesn't care what aircraft, weight or speed. The older M-5 you would dial in stuff. Today the -28's and (mobile) M31 you just make sure it's in battery. ( and in boots)

When the aircraft catches the wire, it pulls out a tape (imagine a yo-yo on its side) That tape is connected on top of a drum filled with fluid (water/anti-freeze). As the tape is pulled out it rotates several stator vanes submerged in the water/glycol mix) that hydraulic resistance creates the friction needed to slow down the aircraft. Eventually rolling out around 800'.

Those giant markings indicate to the pilots where the gear is, much like what was said earlier.

Landing directly on the cable will mess it up. They have durability, but eventually they will break. dasleben fantastic landings in the 76 would certainly do that.

Clear as mud now?

 

[C-182 flyer]

I have some expertise in this realm.

As far as what goes on in the emergency, the "recovery team" would gather as much information as possible via ATC. Weight and engagement speed of the aircraft, any ordinance etc... They would ensure the gear is ready (in battery) and stand by.

The aircraft may either roll in, (land 100-500+Prior) and take the gear, or they may chose to fly-in (utilize the FLOLS or other optical guidance, much like a PAPI)
The E28 is fat ,dumb and happy. It doesn't care what aircraft, weight or speed. The older M-5 you would dial in stuff. Today the -28's and (mobile) M31 you just make sure it's in battery. ( and in boots)

When the aircraft catches the wire, it pulls out a tape (imagine a yo-yo on its side) That tape is connected on top of a drum filled with fluid (water/anti-freeze). As the tape is pulled out it rotates several stator vanes submerged in the water/glycol mix) that hydraulic resistance creates the friction needed to slow down the aircraft. Eventually rolling out around 800'.

Those giant markings indicate to the pilots where the gear is, much like what was said earlier.

Landing directly on the cable will mess it up. They have durability, but eventually they will break. dasleben fantastic landings in the 76 would certainly do that.

Clear as mud now?

Just a little clarification:

For the Super Hornet, the max engagement speed of the E-28 gear is 170 kts on landing for gross weights up to 50,600 pounds. On aborted takeoff, the max engagement speed varies depending on weight from as low as 130 kts at 66,000 pounds to 158 kts at 55,000 pounds. there is also a limit of 40 feet off of centerline. Exceeding these limits may "2 block" the gear and require lots of maintenance to repair it.

As far as roll in or fly in, if you have a controllability problem, you need to fly into the gear, otherwise you would just land normally and roll into the gear. For a fly in, a LSO is preferred since the lens is rarely co-located with the gear, but usually about 1,500 feet from the approach end of the runway, since having it located next to the gear would cause problems during FCLPs by having so landings on top of it and probably knocking it out of battery. If no LSO is available and you have a good INS, the best technique is to put the velocity vector just prior to the gear, and you will nearly fly into it.

After you trap, you will pass the engagement speed and weight to the tower for their records, I have never passed that info while airborne prior to trapping. I too have never heard of a "net" at the field. Field traps are not that rare, any brake, hydraulic, or controlability issues may warrant one, as well as deep standing water on the runway. As they say, "field traps are free," so you may as well take one if you have any doubts.

 

[JDean3204]

that is interesting to know they have barricades as well on land, any reason to use a barricade on land with an A/C? I just dont see the reason to potentially damage the A/C any further when there is a long runway for them to land on. especially if they are equipped with a tail hook to catch the wire.

 

[MikeD]

Just a little clarification:

For the Super Hornet, the max engagement speed is 170 kts on landing for gross weights up to 50,600 pounds. On aborted takeoff, the max engagement speed varies depending on weight from as low as 130 kts at 66,000 pounds to 158 kts at 55,000 pounds. there is also a limit of 40 feet off of centerline. Exceeding these limits may "2 block" the gear and require lots of maintenance to repair it.

Similarly, there are minimum engagement speeds for some systems too. The aforementioned MA-1A barrier at the departure end, rolling over it below 60 knots may result in the system not activating correctly.

After you trap, you will pass the engagement speed and weight to the tower for their records, I have never passed that info while airborne prior to trapping. I too have never heard of a "net" at the field. Field traps are not that rare, any brake, hydraulic, or controlability issues may warrant one, as well as deep standing water on the runway. As they say, "field traps are free," so you may as well take one if you have any doubts.

Ive never seen the BAK-15/61QSII system at any runway end of a NAS or MCAS; only at AFBs.

 

[MikeD]

that is interesting to know they have barricades as well on land, any reason to use a barricade on land with an A/C? I just dont see the reason to potentially damage the A/C any further when there is a long runway for them to land on. especially if they are equipped with a tail hook to catch the wire.

Like I mentioned before, aircraft barriers are designed for non-tailhook equipped aircraft. OR for tailhook equipped aircraft who have aborted, for example, but had a hook skip over the arresting cables or missed them completely or didn't have time to drop the hook. Remember, aircraft barriers are ONLY located in the departure end overrun, and are uni-directional.....they can only be utilized in one direction of travel.

Catching the BAK-15 barrier net will result in some aircraft damage. But the MA-1A barrier, especially in conjunction with a BAK-9 cable right before it (known as a MA-1A MOD), results in no aircraft damage pending everything operates correctly. In some aircraft, ground jettison of low-hanging external stores is required prior to rolling into this system. Picture is a MA-1A MOD post-activation, with barrier net activated following the aircraft nosewheel rolling over the BAK-9 cable portion: