Posts by user "MR8" [Posts: 9 Total up-votes: 0 Pages: 1]

Even though there is no point speculating about the cause of this accident, it is the nature of the beast to have questions. As pilots (most of us at least), we do have an inquiring mindset.

My initial thoughts were an inadvertent flap retraction. But with the ‘evidence’ that has been presented over the last 48 hours, I think we can safely discard that option.

What we think we know is:
- RAT was deployed (highly possible)
- Gear was selected up, but did not operate (bogey tilted, doors remained closed)
- APU was ‘on’ (APU door open on after crash pictures)
- Flight path

Any of these observations, alone, would mean very little. However, in combination, they all point to a dual engine flameout just at/after the rotation. The aircaft has enough kinetic energy to reach roughly 150ft altitude, and then starts a shallow descent at ‘alpha max’ into the buildings ahead. The RAT deployed, APU attempted auto-start, gear was unable to retract.

I only wonder why the engines spooled down. Bird strike seems to be out of the question, so that leaves us with only a very few options, which include a software bug or a suicidal pilot (not a popular option, I understand, but we have to take all options into account).

What I don’t believe is incorrect FCU selections, since that would not explain the high AOA on impact. It also would not explain the RAT, no gear retraction or the APU inlet flap open. Another thing that is highly unlikely is any switching done by the pilots, especially RAT etc.. The airborne time is just too little, pilots usually don’t take any action below approximately 400ft, and these switches are so ‘underused’ that a pilot would not find them instantaneously in a high stress situation.

For me, a dual engine flameout seems the only possible explanation, now we only have to wait for its cause.

You might want to rethink that.
It's approximately 1km glide from where the aircraft was at roughly 200ft, not 2 km. 1km equals about 3000ft, so that is a glide ratio of 15. Taking into account a bit of excess speed to bleed off before reaching alpha max, this sounds very feasible to me.

Who says the aircraft was not in ground mode when that happened? If that glitch happened just before rotation, it would give the aircraft enough energy for the flight path it had imho. Even when the engines are shut off, at that regime, they will still provide some thrust for a few seconds.
My guess is that the glitch occurred during the transition from ground to air mode for some reason...

No, an apparent symmetrical loss of engine thrust can not be explained by FOD. Also, even though the videos are not the highest quality, it is evident that the engines don't seem damaged. There is no smoke, flames or apparent engine stalls (audible) on the video.

No, they did not climb that high. Latest FR24 ADS-B report was indeed 625 ft, but that is based on 1013 (STD). With the local QNH being 1000, that 625ft becomes roughly 300ft MSL. Corrected for airport elevation, this is just above 100ft. The last recorded altitude of the aircraft was roughly 100ft AGL, which does not mean it didn\x92t climb a bit higher, but the aircraft reaching 400ft is pure speculation.

I would take that with a pinch of salt.. Did a 'government official' say that, or is it an official announcement by the government? Big difference..
Additionally, ADS-B data and the triangulation of the video showing the takeoff would lead you to a different conclusion.

Regarding the 'pack issue'.
As mentioned before, the packs are electrical.
What might have happened is that during the engine start sequence, the packs are not working, similar to a conventional bleed system. In an environment of 40˚C, a full cabin heats up very quickly and will take some time to cool down again. This might be conceived by passengers as "the airco isn't working".
I am not a 787 driver, so this is just an educated guess based on my own experience operating in hot temperatures. Any 787 drivers in the know, please back me up or shoot me down if I'm talking nonsense.

Fuel temperature is not the issue. Max Fuel temperature on our Airbus is 53˚C, the B787 will have a similar limitation. Summer in the Middle East is hotter than this without any issue.

Language:

Having lived in the Middle East for over 20 years, I am somewhat used to the Indian use of the English language. Therefore, I wouldn't look too closely at the usage of "transitioned"; it simply means moving from one condition to another.

The conversation of the pilots, on the other hand, will be very interesting. It should be analysed in the language they were speaking, considering whether this was their native language to start with. I assume that the conversation was in Hindi, translated to English for the report. In that case alone, a lot of nuance might have been lost in translation. That's without even considering the tone, volume etc. of the conversation.


Procedure:

I am an Airbus driver, so I am not familiar with the B787 EICAS. On the Bus, the ECAM would generate an ENG FAIL, followed shortly thereafter by an ENG ALL ENGINE FAILURE. I assume the B787 would have a similar event on the EICAS. Now, considering the time frame of how quickly things happened, there is absolutely no reason for the pilots to assume something was wrong with both engine cutoffs, unless they were physically switched off by someone. We are not trained to consider a fuel cutoff switch as the main reason for an engine failure, especially on the takeoff roll.


Question?

When I was a young F/O, some of the captains I flew with had the (annoying) habit of resting their hands just behind the thrust levers on their PM (PNF) sectors to 'be ready' to reject the takeoff. This would put the hands in the vicinity of the Fuel Cutoffs, which would, in turn, increase the chances of an unintended action on these switches. Is this a possibility, or am I way off?