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Sailvi767
2025-06-12T23:16:00 permalink Post: 11899826 |
Takeoff roll and rotation looked normal. No tail clearance or any other issues to indicate anything abnormal until after the main gear left the runway and they were not retracted.
Subjects: Takeoff Roll 1 user liked this post. |
Sailvi767
2025-06-13T01:49:00 permalink Post: 11899917 |
Having read all the posts, watched the videos and with a 30 year background interest in air safety, I have a nagging feeling that the engine fuel cut off switches were pulled just after take-off. I am not saying this with the intention of idle speculation, it is just that to me nothing else seems to make sense. To anyone disagreeing with this, I really hope you are right and I am wrong.
Subjects: Fuel (All) Fuel Cut Off Switches Fuel Cutoff |
Sailvi767
2025-06-13T10:12:00 permalink Post: 11900289 |
Why would you lower the nose and violently slam the aircraft into ground. The crew flew the aircraft exactly like you should in that situation. They traded angle of attack for descent rate and put the aircraft on the ground with the best chance of survival. Unfortunately with at least 110,000 lbs of fuel and buildings on the decent path the outcome was never going to be good. Doing so also bought them time to try and resolve the engine malfunction.
Subjects: None 2 users liked this post. |
Sailvi767
2025-06-13T10:25:00 permalink Post: 11900309 |
Just as an example of how many misconceptions, mistruths, half truths and complete BS there is in this, and any accident, thread consider this\x85
I am very sure the only variant of the 757/767 that had a RAT was the 767-400, which was not in production in 1986. I flew the 767-200 and -300 with 3 different engine combinations (around 30-40 different airframes and 2 airlines) and none of them had a RAT. Happy to be corrected if this model 757 (or 767 as someone in a later post says) had a RAT. Subjects: RAT (All) 3 users liked this post. |
Sailvi767
2025-06-13T10:28:00 permalink Post: 11900313 |
I wondered that myself however the ground roll and initial takeoff all seem normal. In addition I can\x92t conceive of pilots that would not be pushing the thrust levers forward as hard as they could in this situation.
Subjects: None |
Sailvi767
2025-06-13T12:34:00 permalink Post: 11900458 |
If the fuel was cut off, how long would it take until the engines spooled down? How long would it take, given wind-milling etc, for that to result in a loss of power? I'd love to see a timeline of the flight with the fuel being cut off that is remotely compatible with the events we saw, because I don't think it's possible.
Last edited by Sailvi767; 13th Jun 2025 at 13:16 . Subjects: Fuel (All) Fuel Cutoff Fuel Pumps 1 user liked this post. |
Sailvi767
2025-06-13T21:42:00 permalink Post: 11900937 |
Nose down would be to get best glide - longest time in the air and max distance. Raising the nose up leads to a stall and brings the aircraft down faster than best glide. It's counter-intuitive, hence the tendency to pull the nose up in a stall or loss of power has to be trained out of pilots.
Subjects: Flaps (All) Flaps vs Gear 2 users liked this post. |
Sailvi767
2025-06-13T21:48:00 permalink Post: 11900942 |
The requirement to lift the cutoff switch out of the detent before moving it is an important point. However, those switches are close together and unless the the detent requires significant force I suggest that they could be operated together with one hand if that was an intentional action.
Subjects: None 1 user liked this post. |
Sailvi767
2025-06-13T21:53:00 permalink Post: 11900949 |
Retracting the flaps would put them at the back of the power curve where drag increases with decreasing speed, causing the speed to reduce further!
The trouble seems to start at the exact moment the gear should have been raised, putting the flaps up, iso the gear, would cause the kind of loss of lift you see in the video. From there on, being at the back of the power curve, only firewalling the thrust levers and extending the flaps again could have saved them. Subjects: Flap Retraction Flap Setting Flaps (All) 2 users liked this post. |
Sailvi767
2025-06-13T22:31:00 permalink Post: 11900968 |
Not at all unusual. Wind speeds just fifty feet above the ground are often higher than ground level.
Subjects: None 2 users liked this post. |
Sailvi767
2025-06-14T00:34:00 permalink Post: 11901030 |
RAT out? I think not. Sounds like aorflow changes as flaps retracted.
Flap lever quadrant has a gate preventing quick lever movement past F1 position. So if flap lever selected on first movement, the lever goes to F1 position, where only the trailing edge flaps retracted whereas the slats remained at takeoff setting. Hoping against hope it wasn\x92t a brain fart!😖 Subjects: Flap Retraction Flaps (All) RAT (All) 5 users liked this post. |
Sailvi767
2025-06-14T00:46:00 permalink Post: 11901037 |
Does the B787 have auto flap retract ? Possibly a fault in the system could cause the flaps to retract during the take off run which would not give a configuration warning at the start if they were set correctly. Aircraft uses more runway than normal which it seems to have done, crew become aware of the problem near rotation and miss retracting the landing gear while trying to work out what's going on.
Subjects: Gear Retraction |
Sailvi767
2025-06-14T00:55:00 permalink Post: 11901047 |
Default setup is left tank left engine, right tank right engine. Each engine also has two redundant pumps feeding it, meaning it can operate fully and normally on one operational engine fuel pump.
Furthermore, the engines cannot run from the center tank. There's no such thing. The center tank transfers to the outer tanks, when necessary or when running low or to resolve imbalances, either automatically or manually initated by the pilot for whatever reason. The engine fuel pumps only ever draw from their respective tank. It is as thus impossible for the center tank being empty to cause engine shutdown unless the main tanks were also empty, in which case we would: be in a lot of trouble, shouldn't be taking off, and wouldn't have a massive orange fireball. Subjects: Centre Tank Engine Failure (All) Engine Shutdown Fuel (All) Fuel Pumps 11 users liked this post. |
Sailvi767
2025-06-14T02:17:00 permalink Post: 11901081 |
![]() Flap/Slat Load Relief In the primary mode, the flap load relief system protects the flaps from excessive air loads. If flap airspeed placard limits are exceeded with the flaps in the 15 through 30 position, LOAD RELIEF is displayed and the flaps automatically retract to a safe position appropriate to the airspeed. Load relief retraction is limited to flaps 5. When airspeed is reduced, the flaps automatically re–extend as airspeed allows. Re–extension is limited to the commanded flap position. Subjects: Flap Setting Flaps (All) |
Sailvi767
2025-06-14T15:55:00 permalink Post: 11901596 |
Subjects: Fuel (All) Fuel Pumps Generators/Alternators 2 users liked this post. |
Sailvi767
2025-06-14T16:00:00 permalink Post: 11901602 |
Engine parameters are generally data linked in bursts. Usually every 30 minutes. If an engine parameter goes out of limits normally an alert will de sent immediately but in this case I doubt the alert would gave been sent before the power interruption. The black box will tell the story.
Subjects: Parameters 1 user liked this post. |
Sailvi767
2025-06-15T10:58:00 permalink Post: 11902355 |
This is probably a very stupid question, but what would happen if a BPCU fault (or other cause) led to VFSGs on opposite sides of the aircraft being connected to the same 230 VAC bus?
My understanding is that the left engine VFSGs are not synchronized in frequency or phase with the right engine VFSGs. Cross-connecting them, electrically, could be quite violent from both an electrical and mechanical perspective. Is it realistically possible that the torque shock from cross-connected VFSGs could damage their associated accessory drive trains to the extent that the associated FADEC alternators would no longer make power? In this situation, there would be a loss of aircraft electrical power due to the BPCU fault, no FADEC alternator power due to damage to the accessory drive train, and, therefore, no engine thrust. I presume each VFSG has a frangible link to protect the accessory drive train in the event the VFSG seizes up, which ought to make this loss-of-engine-thrust scenario impossible, but presumption is not knowledge, and this is a possible failure chain that doesn't involve stacking up multiple 10e-9 events. Subjects: FADEC Fuel (All) Fuel Pumps Generators/Alternators Hydraulic Failure (All) Hydraulic Pumps 3 users liked this post. |
Sailvi767
2025-06-16T00:11:00 permalink Post: 11902995 |
Experienced 777 driver. Have tried to solve the puzzle. Looked carefully at the video in this article many times - see below and use full screen.
I might see a small puff of smoke and a smoke-ring just before they pass the shed. Indications of en enginefailure. I also see the wings tilt briefly - a few degrees - towards left. Correct procedure after enginefailure is to tilt the wings about 3 degrees toward the engine that is still running. I also see them climb at a - it seems - too high angle for the actual conditions if engine has failed. That will kill the nescessary engineoutspeed in a few seconds and be hard to recover from. If - and I say if - they in this stressed situation managed to shot down the wrong engine following the engineout procedures the RAT would come out. That would probably preoccupy them so much they forget everything about gear and flaps.. It is a situation I believe most experienced 777 / 787 pilots would recognise as a possibility and would explain everything. But this is pure speculation. Lets wait and see what the investigation teams find out... https://www.aerotime.aero/articles/a...w-so-far-crash Subjects: Engine Failure (All) Flaps (All) Flaps vs Gear MLG Tilt RAT (All) Wrong Engine 4 users liked this post. |
Sailvi767
2025-06-16T00:11:00 permalink Post: 11903728 |
Experienced 777 driver. Have tried to solve the puzzle. Looked carefully at the video in this article many times - see below and use full screen.
I might see a small puff of smoke and a smoke-ring just before they pass the shed. Indications of en enginefailure. I also see the wings tilt briefly - a few degrees - towards left. Correct procedure after enginefailure is to tilt the wings about 3 degrees toward the engine that is still running. I also see them climb at a - it seems - too high angle for the actual conditions if engine has failed. That will kill the nescessary engineoutspeed in a few seconds and be hard to recover from. If - and I say if - they in this stressed situation managed to shot down the wrong engine following the engineout procedures the RAT would come out. That would probably preoccupy them so much they forget everything about gear and flaps.. It is a situation I believe most experienced 777 / 787 pilots would recognise as a possibility and would explain everything. But this is pure speculation. Lets wait and see what the investigation teams find out... https://www.aerotime.aero/articles/a...w-so-far-crash Subjects: Engine Failure (All) Flaps (All) Flaps vs Gear MLG Tilt RAT (All) Wrong Engine 1 user liked this post. |
Sailvi767
2025-06-17T22:28:00 permalink Post: 11904720 |
767 pilot here, on the 767 it would capture the altitude, but more importantly, it would freeze the airspeed at whatever speed the alt capture occurred at. So the thrust levers would retard to maintain the much slower speed at the point of capture. This could be a possible scenario, especially if the crew was slow to realize what happened, AND the 787 has a similar low altitude capture issue.
Subjects: None |