Airasia Plane Missing?

[Kip Powick]

Even though much of the wreckage may have been "man-handled", during recovery it certainly doesn't look like it was a low speed impact with the ocean.

Thanks for the pics.

[Specs]

Final report here

http://kemhubri.dephub.go.id/knkt/ntsc_home/ntsc.htm

[Don Hudson]

The Airbus has a very clear procedure for resetting CBs which is set out in the QRH. If it isn't in the list and procedures on how exactly to re-cycle CBs, then it shouldn't be done in flight, period. One doesn't troubleshoot beyond the book in an electric airplane. I should think this goes for the Boeing as well, particularly the B787.

A corollary to that standard is, no CB reset procedure requires either pilot to get out of their seat.

That's why Airbus located most of the aircraft's CBs downstairs in the EE compartment, with only a few left on the rear overhead panel.

But once again, this is not an system or design accident, this is a performance accident. I haven't read the report thoroughly yet but at fourty-six years old the PF (right seat) only had 2000hrs - not a lot of time if it's only accumulated in normal ops; that's an outlier that needs to be examined.

I understand that the stall warning continued working despite CAS being below 60kts; some will recall that the stall warning stopped at 60kts IAS due NCD, (no computed data).

[Woody Pusher]

Don,

A basic maintenance problem that hadn't been followed through to source due its intermittent nature.

Compounded by stupid attempts to clear the problem in the air using "ground only" techniques.

Culminating in the FO adopting the AF447 mode, and seemingly unaware the aircraft had switched to Alternate Law, making those lovely Normal Law protections worthless.

The CVR transcripts appear to be extremely truncated, and I note the BEA isn't happy with that.

[Don Hudson]

Yes, noticed the obvious truncation/editing - true to form for the NTSC I think.

An MEL is a dispatch tool to get the airplane to where it can be repaired within the time frame specified; it isn't to be used as a planning tool but that's exactly what this looks like here as the snag was frequent and long.

Pilots are, at heart, "problem-solvers", and the message was, albeit innocent enough, a "problem", a nuisance and in some circumstances a serious distraction. I doubt if crews had the power to say, "fix it or give me another aircraft".

However, there is nothing in the pulling of the FAC CBs that should have resulted in what came next.

[boestar]

When I was working on the Global Express program at Bombardier several years ago I was facinated by the method used for Circuit breakers. The system is completely solid state and all the breakers are opened or closed by selecting them on a CDU on the console. Many were restricted as to how many times you could reset it. The system is very good but Transport still had some critical and primary systems limited to standard circuit breakers.

[Woody Pusher]

However, there is nothing in the pulling of the FAC CBs that should have resulted in what came next.

Couldn't agree more.

The root cause though, goes back to poor PCB design where board solder connections hadn't been encapsulated to prevent corrosion. The secondary cause was believing that either cycling the FAC CBs, or changing out the FAC(s) was fixing the problem. If a changed out FAC had been sent back to the manufacturer, their tests would have proved there was nothing wrong with it, and in this case the problem would lead to the RTLU and associated electronics.

None of that appears to have happened.

The failure of the Capt to switch OFF the overhead FAC switch before pulling the associated CB, led to him thinking that when he reset the CB the FAC would operate again, when in fact he needed to switch the FAC ON as its latching function caused it to turn OFF when the CB was pulled. He then pulled the second FAC CB, resulting in the aircraft going into Alternate Law.

The resulting loss of control, dual inputs, "pull" instead of "push" etc., is a sad repeat of other accidents.