American Airlines jet goes off runway in Jackson Hole, Wyoming

[protectthehornet]

WINO makes a fine point. I wonder if the landing touchdown was ultra smooth? and didn't compress the gear struts.

something simliar with a different type at little rock...on all landings the spoilers should be checked as deployed...not that this deserves reading the CVR, but it would be an interesting listen

[Smoketrails]

I still reckon he touches down at 0.24(1st thump) and you see the papi's flash by at 0.27(2nd thump as nosewheel touches down!?)?

[Checkboard]

Failure of the air/ground sensor will cause an exact duplicate of the video...

In the 737, the reversers can be deployed from 10' radio altitude and below - no ground sensor input required.

Is the 757 (both Boeing products) that different?

[con-pilot]

In the 727 you can deploy the TRs anytime you want. I was under the impression it was the same for the 757.

[Spooky 2]

You need to be on the ground or at least the MLG needs to be on the ground.

[SKS777FLYER]

On 757, main landing gear needs to be compressed for thrust reverse to actuate with throttles against the idle stop, same for ground spoilers to deploy. Reverse thrust is modulated manually, but there occurs every now and then the refusal of the engine to actually go into reverse thrust, causing the pilot to try to coax the reverse levers out of their lock detents. In the event the ground spoilers don't deploy automatically (AA SOP is spoilers armed for every landing) the PNF calls out "NO SPOILERS" and if the Captain is flying, he moves his hands from the throttles and quickly manually deploys the ground spoilers. If the FO is flying, the Captain announces "No Spoilers" and the Captain manually actuates them. If auto-brakes are armed and come on at wheel spin-up, at settings of 4 or MAX, the nose will come down rapidly. I did not detect in the video, the near instant settling/compressing, (maybe 18-24" ?) of struts that occur on touchdown with weight transferred to wheels that spoiler deployment causes. Also did not detect the quick almost nose-slam to the runway that hi level auto-brake causes.
I don't think the pilots would fail to arm spoilers or auto brakes particularly at JAC with it's high elevation, short pavement, frequently slippery far end and maybe a jet near max landing weight (ferry fuel?) as well as usually a full load of pax and equipment for the slopes.

[con-pilot]

Okay, I was under the wrong impression, thanks to both of you.

Now, any chance of contamination (ice) of the WOW/squat switches being iced up from inclement weather at the departure airport, then giving a false reading? That has happened to me in the past a few times in different types of aircraft.

[SKS777FLYER]

Smoketrails;
I think you are probably right about the touchdown prior to the PAPI. At just shy of 28 seconds, I got the video to stop, and there is a clear frame of the orange windsock.

[protectthehornet]

I guess about 17 years ago or so, an F100 landed at ORD. It couldn't stop...they went off the last turnoff at highspeed skidding around the turn onto the taxiway...finally the copilot reached up and turned OFF the anti skid and they got normal (without anti skid) braking and stopped.

the plane didn't recognize it was on the ground, so no reverse, no spoilers, no anti skid brake.

ALL planes should have a nice big button that says: AIRPLANE YOU ARE ON THE GROUND< ACT LIKE IT.

I so respect planes like the 727 and the DC9...granted, you had to have enough sense to not deploy reversers in flight or ground spoilers in flight...but if you had to, you could!

[repulo]

SKS,

I think you are close to what might have happened, just one minor comment:
The nose won´t slam down if braking action is between medium and poor, regardless of AB setting. And those are the friction co. they probably have encountered. If there is hardly any braking action, then there is no force opposite to flight direction below the CG that will cause an acc. along the lateral axis.
Regards

repulo

[BOAC]

Still puzzled by the early small opening of the sleeve as spotted by Cough - what particular function/malfunction could cause that? Also are the 757 techies saying that unlike the 737, the 757 must have WoW set?

[Cough]

BOAC -

QRH for the 757 says in the landing gear section, WOW failure in air mode will cause-

1.No rev thrust on 1 or 2 engines.
2.Auto speedbrake inop
3.Autobrake inop.

However, we have no evidence of items 2 or 3 as yet.

** Just for reference, the above items came from a 757 QRH with a different engine fit than the AA aircraft**

The NTSB prelim report seems to indicate that there was a reasonable payload on board.

[BOAC]

Thanks Cough- I've just located the 'tech' info too. A possible lead, but still I cannot understand the initial movement of the sleeve.

[misd-agin]

The video link has been removed.

[411A]

but still I cannot understand the initial movement of the sleeve.

In the end, I believe it will be called...an American Airlines crew ****-up.

[Out Of Trim]

Did a search for the link on YouTube and found another version with Commentary from AvWeb..

YouTube - 757 Jackson Hole Runway Overrun Wednesday December 29, 2010

[bearfoil]

On the plus side, excellent maintenance of Directional Control, nobody hurt, and someone remembered their catechism, as evidenced by the prayer when the tuff old bird started bouncing along the toboggan trail.

Thought I heard some German, and let's remember that this was a destination resort with excellent skiing and amenities, the a/c was full of tourists, skis, snowboards, and luggage. 181 SOB, no spoilers, late thrustR, early touch, etc. Good outcome. 6500 feet? 757?? Any 1011 pilots have some input??

[kappa]

We have already had input from 1011 pilot 411A, i.e., the usual AA bashing - nothing of value.

[Pilot DAR]

I believe it will be called...an American Airlines crew ****-up

We obviously have a variety of posters here, whose opinions span the full range of attitude, and skill/experience. I have no role whatever in assigning or speculating upon responsibiliy here, so I will not. In the absence of other authoritative information, I will maintain my confidence that the crew were applying their skill and training to the best of their ability, under the circumstances.

By the way, while I think of it at the moment, a hearty thanks, and well done for all those pilots recently who have accomplished a safe landing, regardless of the circumstances!

There was a problem, our industry gets better because we fix problems, not blame...

[Bealzebub]

The A/G sensing system on the 757 comprises tilt sensors on the main landing gear trucks, and strut compression sensors on the nose landing gear only. The later is only used for stall warning and portions of the warning/caution system.

Thrust reversers utilize the main gear tilt sensors, and can be deployed once the gear is untilted irrespective of the nose gear being on the ground.

Provided the speedbrake lever is in the armed position and the thrust levers are at idle, all 12 spoiler panels should extend as soon as the main gear untilts on the ground. Nomally, a failure in the automatic speedbrake system would result in both an Eicas advisory message and a caution light. In those circumstances the speedbrakes would (normally) be deployed manually after landing. If the speedbrake lever was not armed (in the down position,) there would be no caution or advisory message. If this were to be done intentionally or unintentionally, the spoilers would have to be activated manually on the ground.

Irrespective of the position of the speedbrake lever, as soon as the first thrust lever is moved to the reverse idle detent, the spoiler panels will fully extend and the lever will move to the up position.

This isn't to add any speculation to what might or might not have happened in this incident, but to clarify the system on the 757, that may well differ from some other aircraft types.