Posts about: "Flaps vs Gear" [Posts: 61 Pages: 4]

It obviously got off the ground before the runway end and apparently reached 635ft, at which point you'd expect gear up, flaps down, but the opposite has happened.

No speculation as to what caused the crash, but a couple of points. If there was an inadvertent retraction of flaps instead of gear, this could potentially be remedied by reselecting flaps promptly once recognised. Whether the startle factor would allow it is another thing.

If the RAT is indeed out and there was some sort of powerplant issue, ie. double engine failure, I don't think I would be in a hurry to retract the gear either. In fact it may well have been put down again in that scenario.

Regardless, awful footage to watch. RIP.

Personally I think take off flaps are extended. It's a grainy video but if you compare it to a normal 787 take off, you can see the profile is similar. The 787 has a sleek wing, even with take off flap deployed.

The 787 screams blue murder at you if you take off without flap. I think selecting flaps up instead of gear up is also unlikely.

The gear not being retracted could be due to confusion in the cockpit/workload.

I'm thinking perhaps a take off performance mis-calculation and/or power issue.

https://www.flightglobal.com/probe-d...121461.article

No idea what happens to a Dreamliner, but the A320 series can handle flaps instead of gear retraction

The loss of lift would begin immediately.

It looks like they used up an awful lot of runway so potentially incorrect performance and thrust setting, incorrect flap setting, chuck in a temperature inversion or changing winds too if you like and mistakenly retracting flaps instead of the gear could well be the last orifice of the Emmental.

A mayday call will normally contain information about the nature of the emergency.
The flaps instead of gear is based on the landing gear being down throughout the whole emergency. It\x92s just weird. I get that it may be overlooked in a stressful situation, but when they had time for a mayday call?
So, someone said the 747 will have an early thrust reduction if you retract flaps too early, is this also the case with the 787?

hasn\x92t every jet had a take off configuration warning for about 30 years now? Surely the 787 has something far more advanced than that (electronic checklists) as well as airlines having various SOPs to catch that. Retracting flaps instead of gear is plausible (but as I said above doesn\x92t really align with the apparent mayday call they got out) but taking off with zero flaps would be unthinkable for anything as modern as a Dreamliner surely

Mayday call could just be a panicked reaction to not having a clue what was happening.

Except here it's 40\xb0C SAT

Agree 10000% this is what I feel the most likely thing is. No indication of engine failure, no indication of bird strike, no indication of Ram Air deployed (would it even have time to deploy? The plane crashed like 30 seconds after take off) The take off run was way long, low power/flaps misconfig. I think we will find the reason out very quickly.

It looks like an action slip to me as the timing looks right ie \x93positive rate \x93 \x93gear up\x94 (someone raises the flaps instead of the gear) PF is looking through the HUD so just sees someone move their hand rather than the hand moving the correct lever

It\x92s then taking off heavy weight with 35c and the flaps have been raised and the gear is still down.

As nobody realised the flaps had been raised instead of the gear when it happened they automatically think it\x92s some other issue as the aircraft loses lift and the amber band rapidly rises and the aircraft runs out of lift.

could be something else like fuel or 2 engine failure but seems possible it\x92s an action slip also.

I didn\x92t see the RAT deployed but saw the gear down still and an aircraft fall out of the sky with what sounded like engines running still.

In the high-def photo of the wing post-crash that has been posted in this thread, the flaps are visibly extended.

Also, unless we are all watching very different videos, I don't quite understand how anyone cannot hear the propeller buzzing in the video of the plane passing overhead. It's quite distinct. Though of course in this new age of AI we should take any and all audio/video with a grain of salt - which is exactly why confidence that the flaps are or aren't retracted based on such low-quality footage is a bit silly to me.

I think it may be a simple case of inaccurate takeoff performance data, or inadvertent retraction of flaps instead of gear (this can happen and does happen).

I'm no expert and open to discussion, but it looks to me like the slats are somewhat extended but the flaps weren't, or at least not from the angles we have seen so far. The autogap system on the B787 will automatically extend the slats if they are already in the middle position (i.e Flaps 1) with KIAS <225. Perhaps, either the inaccurate input for takeoff performance produced figures that allowed a Flaps 1 departure, leading to a longer takeoff roll and then once out of ground effect, insufficient climb gradient and a pilot induced stall. Alternatively, at the point where you would likely ask for gear up, the PM has inadvertently selected Flaps 1 from Flaps 5 leading to the same effect. Pilots experienced startle and shock, declared a Mayday as they knew they were descending when they shouldn't be and didn't have time to appropriately react.

Dual engine failure is obviously a possibilty however rare it might be. but it doesn't look like any catastrophic failure from the video. Clearly a sad day for all in aviation and looking forward to the official investigation and results, hopefully something we can all learn from.

This was my thought. tf were they doing making a radio call in that situation.

My money is on hot, heavy, engine failure and PNF raises flaps instead of gear for now

Having experience of many crash sites over a long career, taking off without flaps with the config horn/ warning blaring (or not if u/s) is a possibility Also selecting flaps up, instead of gear up at the positive rate of climb call, is also not unheard of and has happened. Both engines failing/ losing power at rotation/ initial climb out would be extremely rare, but not impossible. With the descent and lack of climb clear, unless a mistake of retracting flaps instead of gear, why wasn't the gear selected up as dragging that around is only going to end one way.
he sound from the well documented video would suggest the engines were running, but were certainly not selected to TOGA/ full power which you might expect when faced with high buildings growing larger in the windshield.
Due to the tail section being relatively intact, the CVR/ DFDR will be downloaded very soon, if not already, so we will all know shortly....

The speculation that the pilot monitoring retracted the flaps instead of the gear is a valid one. There are a few incidents off the top of my head that I can think of. The BEA trident in Staines that stalled and crashed had had its droops retracted early, the Nepal ATR on approach, the PF called for flaps 30 and the PM pulled the props to feather and more recently when the BA 777 pilot at Gatwick pulled the power back instead of pulling on the yoke at Vr. As they say, if it can happen, it will happen.

I am curious how this can happen? The handle for the gear is on a completely different place in the cockpit that the flaps handle.
Possibly a B787 pilot could give us an idea?

What is nearby the flaps handle are the switches for the "fuel control".

BOEING, AIRBUS, MD, it doesn't matter, handles for Gear, Flaps different places, different shape. But it has happened and it will happen.....

Ive seen it happen in a previous (ground based) life fairly frequently (in relative terms) but exclusively during descent/approach. Usually the context would be expecting a flap call but when the gear call is made the flap handle is moved and quickly returned to the previous gated position followed immediately by gear selection, confirmed upon review of the data. To happen on takeoff would be most unusual, and although the CCTV footage is indicative of it being highly plausible, neither pieces of footage really show anything to draw any conclusions on. Certainly there may be numerous aspects to this, perhaps there was some catastrophic electrical failure that wasn\x92t of itself an immediate threat to the flight but the startle effect in the flight deck prompted other reactions. It\x92s impossible to know based off the information available. The human element will form a significant part of the investigation regardless of root cause(s).

Regarding the comments about who should be allowed to comment on such threads. I like the fact the mods have taken a pragmatic view of this. Theres a reason many in the accident investigation field come from an engineering background. Whilst highly experienced pilots are clearly crucial on an SME level, there can be a tendency for iwouldnthavedoneitthatway-itis. This can at times hinder investigations where an open mind free from confirmation bias is essential.