Qantas A330 Emergency Landing in Learmonth

[ampclamp]

to old fella

Thanks OF.
Being inside the tent I have heard absolutely nothing from alaea guys or lame's on the job regarding blaming this event on any maintenance issues either internal or external.Not even heresay let alone anything official
The reports saying these things frankly are crap imho or have been made by some crank without a clue shooting from the hip.
That privilege of course is reserved for us here

[Capn Bloggs]

ampan,

Computers either work, or crash.

The only work properly if they are programmed correctly. In this case, how on earth could one dud ADIRU cause such a dangerous incident? It seems to me because the system ie the other computers hadn't been programmed sufficiently well to cope with a dicky ADIRU. That's not the machine's fault, that's the fault of the human programmers.

[404 Titan]

Funny thing is I had an ADIRU fault on one of our flights to London the other night without a problem. I suspect there is more to this fault than meets the eye and word from our company, "CX" via internal e-mail is that there will be some amendments to the MEL and additional OEB's coming from Airbus is the very near future.

[4PW's]

"It seems almost certain that circuit breakers were pulled prior to the incident when, in conjunction with Maintenance, the pilots were attempting to address an ECAM."

I'll not quote the source.

Just please tell me this isn't so....

[Short_Circuit]

circuit breakers were pulled prior to the incident when

Now there is a realistic scenario at last. I Bet you are correct.

[OhSpareMe]

Errr yeah, really?

The only problem with that is the lack of any 'circuit breakers' on the flight deck of the A330. They were most likely attempting to 'reset' computers.

[404 Titan]

4PW's

Yep as OhSpareMe has stated. Not possible in the A330/340. There are only resest switches on the flight deck. All circuit breakers are in the avionics bay and are strictly not accessable in flight.

[skol]

Maybe the rest of us couldn't have done it.

Ex-fighter pilot saved plunging flight - New Zealand's source for World News on Stuff.co.nz

[peuce]

In a FBW aircraft such as the A330, can the pilot ever select "full" manual control ... or are his inpurts always "vetted" by the flight control computers?

[404 Titan]

peuce

Yes. If the pilot wants to fly the aircraft in "Direct Law" they can after pushing three buttons.

[peuce]

Thanks 404 Titan.

I was wondering how the pilots got the beast under control if erroneous data was continuing to be fed to the flight control computers.

[captaintunedog777]

Heard the same about the conflicting data. Fantastic job done by the crew involved.

[4PW's]

Fair enough, no CB's to hand. I'll ask the fellow again. He's a Boeing pilot, after all. It's a bloody good job they're all alive. Well done to the pilot(s). Just read this report: AAIB Bulletin No: 6/2001 Ref: EW/C2000/10/2 Category: 1.1. Seems to me a little knowledge is dangerous, and I have only a little knowledge of Airbus aircraft and systems logic, so perhaps 404 or someone with the good oil might briefly explain how the A/P can simply disengage because of an overspeed, then climb to lose the airspeed excursion. Did I interpret the report on that correctly, and is there a similarity with QF's A330 incident, or was it human induced? Don't get testy, Keg, et al. This is a valid question. Two major events in a short period of time, the near hull loss of a B744 and a jet upset in an A330, are points in the history of any airline to pay attention to.

[Capn Bloggs]

From 4PWs,

"It seems almost certain that circuit breakers were pulled prior to the incident when, in conjunction with Maintenance, the pilots were attempting to address an ECAM."

I'll not quote the source.

Just please tell me this isn't so....

How about we try to verify that what we are posting is not total nonsense before we post? Or at least ask the question "is it possible to pul CBs in the A330" instead of implying the crew were doing so by saying "please tell me this isn't so".

[4PW's]

Whatever you say, Captain.

[Teal]

New angle....

Base&squo;s signals may have caused plane&squo;s computer glitch caused Qantas plunge | PerthNow

Ironically, the claims may have come from pprune posts refering to the high-powered VLF transmissions from the Harold E. Holt Naval Communication Station north of Exmouth.

[allthecoolnamesarego]

briefly explain how the A/P can simply disengage because of an overspeed, then climb to lose the airspeed excursion

As the Bus is a FBW aircraft, it is controlled by computers (obviously). The FBW technology means that there are effectively a few layers. Firstly, the control surface deflections are all computer controlled,. The aircraft has auto-trim (put the stick in a position, let it go and the aircraft will hold that attitude). The FBW is almost (simplistically) a dumb autopilot - it sets and hold control surface positions. It also has an ability (a bit smarter than dumb) to realise when things aren't right, and change control surface deflections to 'fix' the problem.

This FBW technology allows the aircraft to have a series of protections, one being an overspeed protection. When an overspeed is detected, the control surfaces are deflected by the flight computers to change the attitude and prevent an overspeed, just as a pilot would...

The autopilot is a layer above the FBW (the smart side of the aircraft). This operates like any autopilot, tracking, height conntrol etc etc.

When something is amiss (ie overspeed) the autopilot will drop out and the the FBW protections will kick in, to fix/control the problem.

So basically, the FBW is a 'basic' control, and the autopilot is a level above.

Hope this makes sense

[Old Fella]

Overspeed protection

allthecoolnamesarego. Your statement "When an over-speed is detected, the flight control surfaces are deflected by the flight computers to change the attitude and prevent an over-speed, just as a pilot would" seems to imply that no reduction in thrust is automatically made. As an older F/E I really do not have any in-depth knowledge of the intricacies of FBW aircraft system operations and as you make no mention of what happens to thrust settings in the event of an over-speed I ask, "does the crew have any control of thrust, in a case such as happened with QF72, without reverting to what is known as Direct Law mode"?

[4PW's]

Thanks for the reply, Names, but I don't understand why that'd be so in a Bus. That is probably because I've only ever driven pistons, turbo props and Boeing's.

In such simple airframes, if an overspeed was about to occur or had occurred the idea is to retard the thrust levers with the autothrottle engaged by either manually pulling the levers back to the stop or intervening in the engaged autothrottle mode.

Not to start a competition between manufacturers, but the autopilot is not disconnected to regain airspeed in anything I know of that resembles an airplane.

With all due respect, is that really what the Airbus would do?

[Capn Bloggs]

Thread drift, but for those of you interested in what an Airbus can get up to in an overspeed scenario, read this (from the Rumours and News thread). Don't cruise directly above an Airbus?