Posts by user "Sailvi767" [Posts: 57 Total up-votes: 0 Pages: 3]

Originally Posted by TURIN

May I ask where this information of load shedding comes from please
In my experience the APU supplies enough power to run all systems. Hydraulic pumps, fuel pumps etc

Originally Posted by MaybeItIs

Sorry, you missed the point I was trying to make. \xa7 25.903(b) does say that the fuel system must be able to operate in an isolated, two-sided mode (for a twin engined jet), such that nothing on one side, such as bad fuel, will adversely affect the other engine. Of course, during Takeoff, both sides drawing fuel from a Centre Tank containing a lot of contaminants (e.g. Fuel Bug matter, water) is a scenario that could bring down the plane. We are all aware of that. But the point I was trying to make is that although \xa7 25.903(b) requires "at least one configuration" that separates both systems entirely (such as Left engine drawing from Left Main Tank, and Right from Right) which can be configured, the Rule doesn't appear to make that compulsory for Takeoff.

A lot of other posters here have stated that according to FCOM instructions, the normal, accepted 787 Takeoff configuration is "Both sides draw from centre" if the Centre tanks have enough fuel in them. I think (maybe wrongly) that this (prior few posts) is the first time this exact point has been raised. I hope I'm correct there. If not, my humble apologies.

The great thing about this forum and sadly, this tragic accident, is that it's drawing a few previously little-known worms out of the woodwork.

Originally Posted by vilas

RAT doesn't help retracting the gear. Full conversation hasn't come out. First thing should have been positive rate but it appears engines started winding down as they got airborne so attention shifted to engines.

Originally Posted by Musician

Was the RAT deployed manually?
The report says, This was 5 seconds after the fuel was cut off.

It suggests to me that the RAT deployment was initiated while the engines were still above idle and generating electrical power. Obviously one of the pilots could have done it via depressing the switch, as it's a "dual engine failure/stall" memory item (see Air India Ahmedabad accident 12th June 2025 Part 2 ) that won't hurt anything.

Is there a way for the RAT to deploy while the engines are still above idle?

Originally Posted by AfricanSkies

10 seconds to respond is a long long time if you’ve just made a silly mistake, you’d have those switches back on in a second. The startle factor isn’t really a factor here, because you know what just happened.
What is also unusual to me is the 4 second gap between moving Eng 1 fuel switch from cutoff to run, and moving Eng 2 fuel switch from cutoff to run.

One would imagine that in this situation, speed of response would have been critical. Why the slow, deliberate ‘reaction’?

Originally Posted by jimtx

They don't have to be positively lifted if the detent rounded out due to wear or if the switch installed was one that the SAIB referenced with the locking feature disengaged. I can't discern a raised boss on the body of the left switch in Fig.13, page 10 of the AAIB report. I assume those switches have some internal over center locking mechanism also besides the spring on the lever that would not be needed if there was no detent. I do remember writing up a 767 switch a long time ago when the Captain noticed the detent was worn and he could shut down without lifting.

Originally Posted by JPI33600

I beg to differ: not from a pilot's point of view who didn't read the bulletin. Please see below about the recommended "tug".

Not a pilot, but electronics engineer here: I finally understood what's wrong with the "defective" switches: on such a switch, if you raise it up (to change its position) and you turn it slightly clockwise or counterclockwise before releasing it, it will operate normally, but the detents are now "crossing" the lock tab, and this one doesn't prevent a move-it-without-raising-it-first action anymore. As far as I can tell from the position of the switches, you have to extend your arm sideways and put some effort in your wrist to activate these switches: chances are that such a movement results in some amount of rotation.



Agreed, but this "test" won't tell you if the detents are aligned or misaligned with the lock tab.



If both switches are "defective" ones (remember, that doesn't mean they don't do their job, only that some specific action may put them in a state where protection against unwanted action is lost), the same action from the same pilot may well put both switches in the dangerous configuration.

By the way, I find that the "check" recommended in the bulletin for a switch suspected from being "defective" is incredibly misleading. It will possibly detect a switch where the cap has already been turned, resulting in a misalignment of the lock tab with the detents, but it won't detect a switch waiting for a turn to put it in the dangerous configuration. The "check" should be "pull on the cap to raise it, try to turn it clockwise or counterclockwise while raised: if it can be turned, it's defective".



On the contrary, according to the above scenario, anything interacting with the switches (which are close to each other) can move them unexpectedly (the "iPhone falling" case), and the CVR statement would reflect the surprise of a pilot who actually didn't do anything wrong.

May I add that I consider the probability of such a scenario as very very thin, but I wanted to emphasize the fact that we must keep our minds open, instead of jumping to conclusions too early.

Originally Posted by Alty7x7

My recollection is that the fire handle will be locked in this circumstance, unless the respective fuel control switch is at Cutoff. Engine fire procedure (and not before 400 ft AGL) is fuel control switch to Cutoff and then pull the fire handle (turn left for bottle 1, turn right for bottle 2).

Originally Posted by Herc708

Does the EAFR record the electrical / physical contact of the RUN / CUTOFF switch or, does it record a software 'EVENT' which has the same 'signature' as the RUN / CUTOFF switch being toggled. My thoughts are that the RUN / CUTOFF switch never moved but, the underlying software / hardware system mal-functioned triggering a scenario similar to both RUN / CUTOFF switches being triggered

Some Boeing SB's describe circuit board failures triggering all sorts of unexpected / unpredictable failures

Originally Posted by Tailspin Turtle

From the beginning, my impression looking at the final glide video was that they weren't sinking as fast as I would have expected with both engines failed completely. A rough analysis using 787 L/D data, revisited as more speed and altitude estimates became available, convinced me that it was very unlikely that they could have gotten that far in that configuration with not only no thrust, but the drag from that big windmilling front fan on each engine. The preliminary report states they got at least one engine turning, apparently fast enough to reduce that drag and therefore get them to the crash site. However, as tdracer opined, a few more seconds would not have allowed for enough thrust to develop to stop the descent before ground contact.

Originally Posted by AirScotia

Given the engines roaring, headphones etc. - would it have been possible for the PF to hear the switches being clicked?

Originally Posted by AirScotia

So why did they give so much space to a discussion of SAIB NM-18-33? It's obvious that the switches were not faulty, or they'd have said. If they couldn't tell if the switches were faulty, they'd have said. They do tell us that the throttle control module was swapped out and there's been no problem with the switches. So they don't need to mention it. It doesn't read to me as a logical part of the preliminary report, but as something they were under pressure to include to imply that there may have been a technical problem rather than pilot malfunction.

Originally Posted by OhForSure

I have not posted on here in many years, but I feel compelled to do so now. I am a current 787 pilot and I have previously flown most Boeing types and an Airbus too. I also have an extensive background and qualifications in human factors, training and assessment. Before anybody reads any further, perhaps acquaint yourself with the notion of Occam's razor. That is, the simplest explanation is the most likely explanation. I was certain that after the preliminary report was released the preposterous conspiracy theories would finally cease, but no! It's 2025 and humans can no longer help themselves. In my opinion the captain committed suicide here. Simple.

To those suggesting an electrical phantom turned the fuel control switches off without them moving: no. Ask yourselves this: what made one pilot (PF and F/O in my opinion) ask the other "why did you cut off?" Firstly, some context. The 787 fuel control switches make a VERY distinct metallic *CLICK* sound as they are operated. EVERY 787 pilot knows it and won't forget it. It is audible even at high thrust settings owing to the 787's exceptionally quiet engines and cockpit. After rotation the pilot flying is fixated on the HUD; rotating towards the TOGA reference line (~12 degrees pitch attitude) and putting the flight path vector over the flight guidance cue. One hand would be on the control column and the other on the thrust levers. Alternatively he could have had both hands on the control column. In either scenario, the pilot flying's (again, my opinion the F/O's) inboard arm would block his peripheral view (he's focused on the HUD, remember) of the center pedestal and the fuel control switches. HE WOULD NOT SEE THE PM TURN THE FUEL CONTROL SWITCHES OFF. Ipso facto. We know the F/O was PF from the report. If the F/O stopped flying the aircraft and reached down to move the FCS from cutoff to run the captain would've plainly seen the whole thing. I can't imagine "why did you cutoff?" would be his words of choice! More like "WTF ARE YOU DOING?!?" More to the point, if the PF (F/O) did stop flying and reach down to cut one engine off, the captain would have had time to either stop him flicking the second FCS off or at least quickly flick them both back to run and potentially save the day. This plainly did not happen. So it was almost certainly the PM (Capt) that moved the fuel control switches.

So what would make the PF ask the PM "why did you cut off?" if he couldn't see it happen? You would never assume with a loss of thrust that the switches had been turned off. Never. It's not a procedure. It's not a thing. Bird strike? Sure. Fuel Contam? Maybe. But the point is, in the heat of battle at 150 odd feet, you'd never jump to the conclusion that the fuel control switches were off. Never. So what triggered the PF asking the PM why he cutoff? Because he HEARD the fuel control switches move from run to cutoff, that is why. He heard those distinctive *CLICK* sounds (and yes, you can easily flick them both in less than a second FWIW) followed by the engines immediately rolling back. He would then have looked down at the switches and noticed they were in cutoff. The point to be made here is that the switches were moved by the captain. They made their distinct sound. There were no phantoms. They cannot move on their own. They didn't simultaneously fail. This drew the PF's attention away from flying and triggered the question "why did you cutoff"?

Inadvertent selection of the wrong switches? No. The PM was a training captain with thousands of hours experience on the jet. I asked one of our most experienced examiners how many times he'd seen that done. The answer was "zero". Even the stab switches next to them. They're red, guarded and are of a completely different shape and operation. Gear or flap? Come on. I think we're starting to stretch things a bit now. EVEN IF it was inadvertent switching. The INSTANT you'd made that error, you'd go "oh whoops", and flick them back to run. I know startle... I teach it. This is different. You don't flick the fuel control switches off, hear the engines roll back and sit there wondering what happened for 10 seconds AFTER THE F/O JUST ASKED YOU IF YOU CUTOFF! You did something that had an instant effect on the flight. The report indicates that "why did you cutoff" was asked just after both engines rolled back. But it took another 10 seconds to flick the FCS' back to run. If it was inadvertent, the instant the other pilot called out your error you'd correct it. The report makes it clear that there was 10 seconds between that happening. 10 seconds is a LIFETIME in that situation. The training captain knew what he was doing. He only switched the FCS' back to run once he knew it was moot.

So, why did he respond that he didn't move the switches? As per other input from people on here, when people are suicidal they often want to throw authorities off their trail. Or maybe he wanted to confuse the F/O so he didn't flick them back to run himself, or to just buy himself more time while the F/O tried to wrap his head around things? Maybe he didn't want the F/O to die knowing it was a suicide mission. Maybe we'll find out more in the final report or police investigation if things proceed that way. Maybe we'll never know.

I acknowledge that this is my opinion and of course there could be things we don't yet know about, but I must say I'm surprised that some of the theories on this professional pilot forum are no more coherent or logical than those being sprouted on social media.

Originally Posted by EDML

Totally wrong.

The TCMA shuts down one or more engines - but it doesn't move the switches to cut-off in any magical way. TCMA directly operates the fuel valves - but the switches stay on.
Of course there is no entry for the switches being operated on the EAFR when TCMA shuts down an engine!

Originally Posted by appruser

Apologies for the delay in responding to your posts. I see that you and others have stepped in, thanks.

I think for various reasons the ADSB data's absolute values are offset by some amount, for possibly all of the parameters. But there should be consistency in the deltas for the timestamp (by receiving station), the raw baro altitude, the Flightradar24 AGL values, and the airspeed. Flightradar24 themselves note that for altitude " ... the data is not above ground level, but it is consistent to itself."

08:08:46.55 ... 575ft ... 21ft ... 184kt
08:08:48.14 ... 600ft ... 46ft ... 179kt
08:08:48.61 ... 600ft ... 46ft ... 177kt
08:08:49.01 ... 600ft ... 46ft ... 177kt
08:08:49.46 ... 625ft ... 71ft ... 177kt
08:08:49.92 ... 625ft ... 71ft ... 174kt
08:08:50.39 ... 625ft ... 71ft ... 174kt
08:08:50.87 ... 625ft ... 71ft ... 172kt

From the Preliminary Report's airport cctv picture, the RAT was seen deployed at, by my estimate here , 150ft baro altitude, between 4-7 seconds after rotation. So the ADSB readings have to be prior to that.

What's interesting is that the ADSB data covers:
- 4-5 seconds of time (let's approximate 4 seconds from 46.55 to 50.55, ignoring the 0.32s for the moment)
- 50ft of altitude gain
- Declining airspeed from the 1st reading to the last in this final segment from the runway.

Big questions in my mind:
1. If the loss of ADSB corresponds to the E1/E2Fuel Cutoff switches being moved from RUN -> CUTOFF, why is the airspeed declining for the prior 4 seconds?
2. In 4 seconds, why is there only 50ft of altitude gain? that seems odd.
3. To account for only 50ft of alt gain, if we assume the 1st reading is on the runway just before rotation, the intermediate +25ft alt gain is at rotation (Nose up but MLG still on the runway), and the last 4 readings are in the air (nose up an additional 25ft), that means that 1 second or less after lift-off, ADSB was lost - this is before E1/E2 FCO RUN-> CUTOFF.

It's just weird .