Braking seems fine, going by the skid marks left behind. Seems like the loss of directional control. Not sure why it wasn’t slowing, clearly had anti-skid issues. They had quite a bit of runway left.
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DHL Panama.
Their 757s have Pratt & Whitney engines. Unclear from the video, given that it was filmed from the left side, if they were using the Right Engine Reverser during the landing rollout. Does not look like that they used the Left Engine Reverser. Not very familiar with this engines. Can see as plausible cause that they might have used the Right Reverser, and did not stow it as the aircraft slowed down to slower airspeeds. Can see that as a plausible reason to explain the loss of directional control the way they did. |
On a dry runway there is zero issue with using one reverser and directional control. It’s done all the time in normal ops with a reverser locked out. Unless they lost both left and right hydraulic systems braking will be normal. I can’t remember which ones but some spoilers are inop and if I recall you land flaps 20. Easy to float if your not careful. It did not appear either reverser was deployed but stopping should still not be a issue.
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I just had this exact scenario at my yearly checkride. Loss of the left Hydraulic system, run a few checklists, land straight ahead, asymmetric reverser, but a non-event. No nosewheel steering so you’ll need a tow from the runway.
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There is or was an item in B757 QRH for loss of left hydraulics that stated: DO NOT USE AUTOBRAKES. Not saying that is the case here but if they did it can seriously impair directional control as A/B can only give symmetrical braking.. A B757 left the runway in LGW (Gatwick) many years ago as a direct result of this, Airtours I think. Basically with asymmetric reverse any yawing moment can be exacerbated by brakes on one side releasing due to increased lift on one wing and this just multiplies, especially if any crosswind (which appears not the case here) and also if for any reason speed brake not rapidly deployed.
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Originally Posted by Terrey
(Post 11212260)
Landed with a 10kt tailwind, partial flap (Hyd Sys L) , 3000’ elevation and heavy weight. Not surprising they were running out of runway. Landed Rwy07, wind 250/10. Only circling approach available Rwy25 with a displaced threshold. Probably should have looked at going somewhere else.
Is there reliable information that this aircraft was at a heavy weight? Thanks. |
Originally Posted by andrasz
(Post 11212326)
They had another 1000m of surfaced area ahead, more likely it was a loss of directional control. Rudder was deflected left throughout the landing roll.
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Originally Posted by Starbear
(Post 11212493)
There is or was an item in B757 QRH for loss of left hydraulics that stated: DO NOT USE AUTOBRAKES. Not saying that is the case here but if they did it can seriously impair directional control as A/B can only give symmetrical braking.. A B757 left the runway in LGW (Gatwick) many years ago as a direct result of this, Airtours I think. Basically with asymmetric reverse any yawing moment can be exacerbated by brakes on one side releasing due to increased lift on one wing and this just multiplies, especially if any crosswind (which appears not the case here) and also if for any reason speed brake not rapidly deployed.
In the video, you can see the speedbrakes extended but obviouly not all of them due to the Hydraulic failure |
Correct. In fact the speedbrake requirement was in force for the LGW event but that airline omitted that very important point in their own company modified QRH
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Originally Posted by Terrey
(Post 11212260)
Landed with a 10kt tailwind, partial flap (Hyd Sys L) , 3000’ elevation and heavy weight. Not surprising they were running out of runway. Landed Rwy07, wind 250/10. Only circling approach available Rwy25 with a displaced threshold. Probably should have looked at going somewhere else.
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Originally Posted by Sailvi767
(Post 11212532)
If the rudder was left throughout the landing roll it is possible the loss of the Left system caused a NWS issue with a drift to the right. At higher speeds the rudder could compensate but below 80 knots would be ineffective leaving only differential braking.
the nosewheel steering is inop with loss of left hydraulics, so even if rudder trim is used, I’m pretty sure it won’t affect nosewheel steering at all. |
Perhaps the answer lies with why the loss of left hyd sys. Maybe whatever took out the left hyd sys also caused a loss of integrity to the right hyd sys or even the right or left bogie's brakes. It's been a while since I worked the 757. My knowledge is a bit rusty.
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Whatever happened, if it wasn't for these treacherous 5m. terrain level differences within less than 50m from the high-speed exit taxiway, there would only have been a pretty much intact 757 standing in the mud.
If this would have been a high-speed RTO full of pax, veering off the rwy, these 'slopes' could have killed a lot of people... |
Originally Posted by Chiefttp
(Post 11212634)
Sailvi767,
the nosewheel steering is inop with loss of left hydraulics, so even if rudder trim is used, I’m pretty sure it won’t affect nosewheel steering at all. As mentioned earlier, the B757 incident at London Gatwick some years ago, where the operator thought they knew better than Boeing and modified their QRH for Left HYD system failure, meant that the ABS was incorrectly selected for landing. The aircraft lost control directionally when THR RVR was selected and the aircraft departed the paved surface then regained it after a while. It appears similar to this event (no ditches at the side of Gatwick’s runway!). |
Originally Posted by Chiefttp
(Post 11212634)
Sailvi767,
the nosewheel steering is inop with loss of left hydraulics, so even if rudder trim is used, I’m pretty sure it won’t affect nosewheel steering at all. |
Several more videos in AmuDarya’s linked Reddit page above.
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Originally Posted by Cuillin Hills
(Post 11212702)
Not necessarily - I have had a Left Hydraulic fail on a B757 and retained about 14% HYD in the Left system due to the standpipe. This 14% was enough to retain full control of the NWS and taxi clear of the runway.
As mentioned earlier, the B757 incident at London Gatwick some years ago, where the operator thought they knew better than Boeing and modified their QRH for Left HYD system failure, meant that the ABS was incorrectly selected for landing. The aircraft lost control directionally when THR RVR was selected and the aircraft departed the paved surface then regained it after a while. It appears similar to this event (no ditches at the side of Gatwick’s runway!). |
Originally Posted by punkalouver
(Post 11212804)
Anybody have a link to a report on the Gatwick incident?
with an interesting comment on nationwide QRH custom. |
Originally Posted by Sailvi767
(Post 11212532)
If the rudder was left throughout the landing roll it is possible the loss of the Left system caused a NWS issue with a drift to the right. At higher speeds the rudder could compensate but below 80 knots would be ineffective leaving only differential braking.
andrasz too after the stop the rudder is still deflected left, also interesting too see the complete wrinkle/harmonica visible both before and aft of the wing, which may point to the production break locations, and ripping the fuselage open in the middle of the aft section, could point to wingtip touching ground first (ac pivoting on the NLG) causing the wrinkles, and ripping occurring when the horizontal stabiliser hit the ground, I wonder, quite a big dip there, |
Wasn’t there a 757 accident in Guyana two or three years ago where there was a hydraulic problem. Could be an interesting comparison if someone has details.
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