Posts about: "CVR" [Posts: 256 Pages: 13]

Y'all are killing me.
If the intent is malicious, then if you know how the system works then you know how to try and confuse the investigation afterwards so that your family doesn't have to deal with you being the devil who did this. Read the entire of MH 370 if you doubt me.
Yeah.

I had the "opportunity" to investigate more than one fatal crash/mishap, and we dove down into the rat-hole of knobology and switch-ology. I read with some care the posts of one of our more sensible members, PJ2, as regards switches.

I'll leave the CVR extracts to those who want to run down that rat-hole, but WHO was flying and WHO was (doing all else) begins to matter.
Do any of you actually know who was PF and who was PM?
If you know that, how do you know that?

!!!! me, this thread is already going off the rails.

The Preliminary Report clearly states that the co-pilot was the Pilot Flying (PF).

*sigh*

Let's take the sketchy CVR extract as a given for the moment.

So there's this hard working FO doing the takeoff. He wants to do a good job and impress favorably the Training Captain.

For (reasons that I cannot fathom) the training captain On Takeoff On A Revenue Flight chops the fuel before they get to 400 feet AGL.

Yes, that makes no freaking sense. None. Zero. Zip. Nada.

The natural response from PF to the PM (who is the training captain) is some version of "WTF with the fuel switches?"

And the response is "Uh, no, I didn't do that."

Think about this for a moment.

How many "WTF?" things erupt in your brain if that was the sequence of events?

Full Disclosure: I was in charge of the CRM training for the Navy (all of it) for a couple of years (and yes, that was a couple of decades ago). We got our CRM stuff, mostly, From The Commercial Airline Industry.

But, honestly, that reported back and forth between PF and PM has me smacking my forehead in disbelief... given the advanced state of CRM training in today's airline industry.

I confess to you all: I am more confused by this report than I was by the first two days of "data" eruption after the crash.

This is pure speculation but I can envision the following sequence of events that would match the timeline and the little we know from the CVR and sequence of events.
- While PF is concentrated on flying the airplane, PNF moves the switches from RUN to CUTOFF in quick succession (for whatever reason).
- PF doesn't notice that the switches have been moved (again, he is concentrated on flying) but soon perceives the loss of thrust and sees a message on EICAS.
- PF looks down to check throttle position. It takes him a couple seconds to realize that the switches are in CUTOFF position.
- PF asks PNF (and his superior) "Why did you cut off the engines?" (or something similar). PNF anwers that he didn't (a lie, but we don't know if deliberate or just confusion / mental breakdown)
- PF realizes that PNF is in a wrong mental state, and attempts to restart the engines. It takes him a couple of seconds to move both switches because his other hand is on the yoke trying to stabilize the airplane.
- By then the airplane has lost too much energy for a successful recovery. One of the pilots calls MAYDAY because he knows that they are about to crash.
This sequence would match the timeline between the initial fuel cutoff, and when the switches were moved back to run position, and would actually indicate great presence of mind and quick decision from the PF.
Again, this is pure speculation but it would match well with the little information we have.

Sorry, stop right there.
What reason would any 787 Training Captain have for doing that at rotation, or slightly after rotation?
Really. Think about that. It makes Zero Sense.

@tdracers's point about the startle effect is at least plausible.

Thanks for your comment. Agreed, but why did the report make mention of the Stabiliser fault on the previous sector? If this is completely irrelevant, why was it mentioned at all? There a quite a few specifics that are missing from this initial report, such as specific CVR information (what was actually said by the pilots and which pilot said what)? The report also says "...The EAFR data downloaded from forward EAFR is being analyzed in detail..." This indicates that more is known than is in the report. I suspect that the initial report was put out to meet the "30 day rule" and there will be further interim reports before the final.
Fly Safe
PJ88

yes this is the part that has been bugging me also the more I\x92ve thought about it

It\x92s a little annoying that we don\x92t know who spoke the and who denied about the cutoffs but it\x92s kind of the secondary issue.

The 787 has HUDs, PF is looking straight ahead and \x91up\x92 (as the U in HUD suggests), the cutoff toggles are not at all in his field of view , quite similar for the PM

the CVR transcript will have to reveal a lot more because the current sequence of events doesn\x92t really answer that much other than to rule out a few other theories

The fact is that the switches were found in Run position. Everything else is derived from the recorders, and they record electrical signals not physical/visual reality.
As of now we still have no evidence that the switches were - ever - physically in an OFF position. We can surmise from the CVR record that whoever asked the question visually observed their physical position - but it could be that he just read a message.

Pls prove me wrong that we still have no evidence of the actual physical position of the switch toggles during the flight.

It's established fact both fuel control switches moved to CUTOFF 4 seconds after Vr, a deliberate guarded action, not easily done accidentally.
The CVR records one pilot asking “Why did you cut off?”, the other replies “I didn’t”. Then a bland Mayday attributed to the Captain “engine failure, returning” in the middle of the crisis.

The language, if reported correctly, feels strangely detached. No confusion, no urgency, no clear troubleshooting. Not drawing conclusions, but does anyone else see signs of performative behaviour, that is saying the right things outwardly, while being at odds with the underlying cause?

I appreciate that both crew members lost their lives, however if we avoid discussing uncomfortable patterns, we miss the point of investigation and learning.

​​​You might be technically correct here but this line of thinking doesn't fit with the rest of the events. If they weren't physically and observably set to CUTOFF, setting aside the spoken comment, then how were they subsequently reverted to RUN? You would be saying that some invisible systems fault produced a temporary 10 second condition, starting to apply to both switches 1 second apart and ceasing to apply 4 seconds apart. Even within a very low probability scenario, it doesn't seem plausible - this was all physical, for reasons unknown.

Really? It suggests to me and I would imagine the vast majority of us who have flown modern Boeings that they were physically moved, by one of the crew, one at a time, the question is why.

From the report it is clear that the switches were selected to cut off, we will likely NEVER know why, maybe the CVR gives a few more clues but we will never know if it was an intentional or accidental act. What is clear is that during rotation you are never fiddling with bags etc.

Why do investigative bodies insist on publishing "transcripts" of recordings - CVR, ATC, Centre etc - rather than the actual recording? I've seen "transcripts" that, on any interpretation whatsoever that is open to anyone reading it, disclose errors by at least one person, which errors don't feature in the report.

Simple example of a "transcript" of CVR audio from a Centre transmission in an actual investigation report: "Visibility 999". What does that "transcript" tell us about what was actually said by Centre? Was it: "nine hundred and ninety nine"? Was it: "nine nine nine"? Was it: "niner niner niner"? If any of those alternatives were true, it would surely follow that an error was made on the part of Centre.

Or maybe there's an error in the purported transcription of the recording. Maybe Centre said: "niner niner niner niner". Or maybe Centre said: "in excess of 10 kilometres".

Solving the mystery of this tragedy depends on what was actually said in the cockpit - the actual words used - by whom - precisely - and exactly when. Yet we still don't even have a published recording of the radio calls between the aircraft and ATC.

I still think it should be possible to identify the voices from the CVR. During taxi out with P2 as pilot flying the exchanges between them should be obvious as to who is speaking. Thus the identity of the pilot asking about cut off would become clear.

That will be easily answered when investigators play CVR recordings to colleagues, family and friends who can recognise and identify the voices.

They probably know that answer but it is omitted from preliminary report.

in that fraught moment of engines not functioning very close to the ground, the last thing to do at this critical moment when you don\x92t really known what has happened is communicate a MayDay. With the buildings looming up fast, the action required is to attempt to restart, as seems to have been done by a pilot putting the fuel switch to \x93run\x94, but too late to rescue aircraft. I think the timing of the MayDay call is strange given that the scenario called for Aviate, Navigate\x85 then Communicate.

This is a Professional Pilot's Forum. Nonsense and bizzaredness doesn't live here.

And the CVR? "why did you cutoff?" ... "I didn't, the ipad did!".

​​​​​​​

Too many people not wanting to acknowledge what is staring them in the face.

The switches were physically moved to cut off. The report says so, they will have heard them on the CVR.

The switches don\x92t move unless you intend to move them. You can give me all the worn mechanism, SAIB, phone/ipad theories you like. You\x92re clutching at straws.

If you had a massive brain fart and moved one to cutoff by mistake, you would realise instantly. These switches are distinctive in sound and feel. You would know what you had done before you had even released it in the cut off position.

Almost instantly you would get aural warnings and pages of EICAS Warnings and advisory\x92s. You\x92d get a massive clunk and momentary blanking of screens as power transferred.

if it was a mistake, you would instantly move it back to run\x85..you sure as hell wouldn\x92t double down and do the second engine.

it\x92s very sad, but I fear it is staring us in the face.

I've been on record in the past advocating for this, but not as the means for intervention. - in the kind of instance we may have seen here, that likely wouldn't have helped anyway - but as a moderating influence on a crew member who may have been contemplating wayward actions. Being observed is often a powerful influence in behavioural extremes.

On edit: and No, I doubt the preliminary report was written to avoid the risk of copycat actions or delay public reaction. The investigatory team are not at all likely to be considering that kind of audience in what is essentially a finding of fact. An altercation would have been caught on the CVR... and reported upon.

With all due respect I disagree I think the prelim report was very sanitised to achieve the aim of a prelim report (are there any urgent safety actions relevant to this accident to be addressed?) whilst avoiding 1) Extreme public reaction 2) Addressing potential criminal behaviour - which the AAIBs are not experts in, nor the correct investigatory authority.
Your final sentence similarly I doubt - I suspect the CVR does reveal a lot more - certainly the timings of the reported interactions. It's just sensitive information... The report was written at 4AM ish Indian time and released shortly afterwards, and I surmise most of the delay was not "what to include" but "what NOT to include" to (only) achieve the aims of a prelim report.
I am not trying to be disrespectful, just put forward a different point of view, and you may well be right...