PPRuNe Forums

PPRuNe Forums (https://www.pprune.org/)
-   Rumours & News (https://www.pprune.org/rumours-news-13/)
-   -   Qantas emergency landing (https://www.pprune.org/rumours-news/348803-qantas-emergency-landing.html)

ferris 7th Oct 2008 11:29

Not CAT
 
Police statement that it was a control failure
"Mr O'Callaghan said he understood the incident was caused by "some sort of systems failure".
from here
Dozens injured in Qantas mid-air incident - News - Travel - theage.com.au

ampclamp 7th Oct 2008 11:40

systems failure?
 
mmmm, who knows but sounds like CAT to me.
not sure how mr o'callahan would know that already.
maybe a crew member or pax said something like we had clear air turbulence and our systems didnt pick it up.Could be construed as a failure when it actually isnt.Just a thought.
its all just talk for now.I look fwd to hearing some facts from investigators or better still the bush telegraph when on duty next.:hmm:

man on the ground 7th Oct 2008 11:46


The police will have absolutely no role to play in this investigation, State or Federal. The Australian Transport Safety Bureau will be running this investigation from the beginning, as per Annex 13.
Let's not read too much into this aspect. The police DO have a role to play. When a Aerodrome Emergency Plan is activated, especially at a non-controlled aerodrome, the police take the coordinating role for the full 'ground response'. They will always 'report/investigate/wrap up any such "event" where they have a major role.

ATSB, who would have been notified by ATC long before the acft landed, will of course conduct the 'aviation investigation' of the actual occurrence itself.

andrasz 7th Oct 2008 11:57

It seems significant that now all news sources, however inaccurate they may be, consistently report 'a sudden change in altitude' and not turbulence. It seems that the event could be a pilot or systems induced upset similar to the China Airlines MD11 some years ago, rather than CAT.

Finn47 7th Oct 2008 12:16

"Plunging 8000 feet in ten seconds", passenger says. Is that credible?

Forced Qantas Airbus plane landing in Exmouth injures 30 passengers

MAN2YKF 7th Oct 2008 12:21

Those carts are leathal.
My wife suffered injuries during an airpocket incident last year on an A310.
Her and the cart were eye level pinned to the celicing at the rear, could of been worse, she had a lucky landing well falling back to the floor.

As for seat belts, the only time i take mine off is for the toilet, but you hear so many unclick as soon as fasten seatbelt sign is turned off.

2ndGen 7th Oct 2008 12:34

This is my relatively uneducated PPL level question so don't shoot me down but it seems to me to be more of a pan pan situation? Whats the dfferent criteria? I thought you pretty much had to be out of options before you declare a mayday?
Still as always its QF pilots doing very well in a tough situation.

sevenstrokeroll 7th Oct 2008 12:38

Well, good job for getting down in one piece.


I've heard that in mountain wave over the USA, a friend had an A320 (that's airbus three twenty) that the plane encountered some sort of overspeed and, instead of jeoparidizing the structure, the plane CLIMBED to reduce speed. Hmmm?

Does anyone know if the plane went UP or DOWN during the control malfunction?

I encourage pilots to monitor the OAT or Static air temp as it can be a harbinger of CAT. If the temp goes up, you go up to avoid cat. Temp goes down you go down.

TO ALL PASSENGERS, stay in your seats with the seatbelt fastened as much as humanly possible...of course using the lavatory or trying to avoid deep vein thrombosis is vital...but have a plan...IF I HIT BUMPS NOW< WHAT AM I GOING TO DO?

megle2 7th Oct 2008 12:42

RFDS WA website presently showing three aircraft enroute to Perth

RFDS Western Operations: Flight Tracking

Porrohman 7th Oct 2008 12:44

Finn47 asked;

"Plunging 8000 feet in ten seconds", passenger says. Is that credible?
When an airliner is cruising normally at say 37,000ft there is, in normal weather conditions, a sensible and safe margin between the aircraft's stall speed and it's critical mach number. It is theoretically possible that a sudden encounter with a jet stream when cruising at high altitude could cause a sudden and significant change in indicated airspeed resulting in either a stall or mach tuck. The higher an aircraft flies, the closer the stall speed gets to the critical mach number and the less safety margin an aircraft has between these limits. An extreme example of this was the U2 which would fly within 5kts of stall speed and 5 kts of the critical mach number when cruising at 70,000ft. It's said that if a U2 performed a tight turn at that altitude it could cause one wing to stall and the other to exceed the critical mach number.

Stalling or mach tuck at cruise altitude caused by a sudden and significant change in wind strength / direction could result in a departure from controlled flight and could cause a significant loss of altitude. I'm not suggesting that this is necessarily what happened to the Qantas A333, just pointing out some basic aerodynamic principles.

Does anyone know what altitude the A333 was cruising at and what the margin between stall speed and critical mach number would be at that altitude?

More info here; Coffin corner (aviation) - Wikipedia, the free encyclopedia

ampclamp 7th Oct 2008 12:49

pan or mayday?
 
If the crew thought they'd lost control mayday maybe the call.
when pax and crew are hurt I'm not sure of the SOP's, prob a mayday on that basis.Maybe flt crew injured , who knows ?

Any qantas drivers here?

ampclamp 7th Oct 2008 12:57

8000 ft in 10 secs
 
800 ft per second / 8000 in 10 secs, man that'd be interesting to say the least.I'd hazard a guess and say thats supersonic at altitude.
Gotta be a mistake.

G-BHEN 7th Oct 2008 12:57

Not sure of the procedures in Oz but I was taught that if you're not sure then declare a Mayday. You can always say after "Ah maybe I should've declared a Pan", but if you declare a Pan then ATC might not realise how serious the situation is.

ampclamp 7th Oct 2008 13:04

pan or mayday
 
I've been in several pan pan pan situations one where I thought we were spearing in.Stab control loss.So perhaps folks being hurt was the key?
Last thing qantas needs is another bent airframe on a big jet.

wiggy 7th Oct 2008 13:04

Multiple injuries, some possibly serious, probably an "entertaining" Cabin enviroment, might be airframe implications ....... FWIW I agree with G-BHEN - "Mayday" it, you can always downgrade to "Pan" and sort the paperwork out later.

Finn47 7th Oct 2008 14:46

This article says, the aircraft dropped 350 feet, according to "sources"...
which I find slightly more credible than the previous 8000 ft...

Qantas jet&squo;s nightmare plunge over Western Australia | Herald Sun

caveokay 7th Oct 2008 14:49


Stalling or mach tuck at cruise altitude caused by a sudden and significant change in wind strength / direction could result in a departure from controlled flight and could cause a significant loss of altitude. I'm not suggesting that this is necessarily what happened to the Qantas A333, just pointing out some basic aerodynamic principles.

Does anyone know what altitude the A333 was cruising at and what the margin between stall speed and critical mach number would be at that altitude?
at FL3xx , can't we take for sure that the acft was flown with both AP and ATR ON and that these systems on new generation acft like A330 are supposed to cope with CAT without ending up in a spin or a dive bombing run ?? if some part of these sytems was U/S or OFF, that's however another story to know how george is going to react :confused: :confused: (an A310 romanian crew had a very bad experience years ago on final to orly :uhoh: )
anyway great airmanship from crew :D and wishes of quick recovery to the roaring forties :* :*

ChristiaanJ 7th Oct 2008 15:45

Quote from BBC News:
"However, Western Australia Police Commissioner Karl O'Callaghan later told the Sydney Morning Herald that he understood the incident had been caused by "some sort of systems failure".
The ultimate expert has spoken. We can all go home now.

vaschandi 7th Oct 2008 16:31

Salut Caveokay
 
AP 1+2 on A330 can only be used in APProach mode (armed) and ILS (auto)tuned!

vanHorck 7th Oct 2008 16:52

as a humble MEP PPL and often SLC can I suggest the statement:
"for your comfort and safety please keep your seatbelts fastened during the flight even when the seatbelt sign is off"
is simply insufficient.

Most of your SLC have never heard of CAT and even if they have, most of them will not expect to end up against the ceiling, at worst they'll expect their cup of coffee in their laps like during normal moderate turbulence.
Some improved statement should explain the risks.

Also it is time that trolleys ran on tracks in the cabin, perhaps on the side of the aisle so that people can pass, because they are the hardest and sharp edged heavy items around and lethal in heavy turbulence.

Even that however will not prevent the painful Stewardess burns of the coffeee can which I once saw in a 737 in sudden turbulence. It can t be that hard to design quick latch/unlatch turbulence safe trolleys on tracks

ChristiaanJ 7th Oct 2008 17:14


Originally Posted by vaschandi
Salut Caveokay
AP 1+2 on A330 can only be used in APProach mode (armed) and ILS (auto)tuned!

I think you'll find caveokay was talking about having and an AP and an ATH engaged, not both APs.
Ah those traps in the English language...

But the reponse to CAT by the AP and ATH would be interesting, if somebody can give a reasoned description.

Never having experienced CAT apart from "cobblestones', never the full 'upset' ... can such an 'upset' be a brief and violent event (negative G and all that) after which you get to sort out the damage, or do you find yourself systematically 15,000 ft lower... with a little help from the AP?

CJ

Globaliser 7th Oct 2008 17:29


Originally Posted by bsieker (Post 4443934)
As long as the "please keep your seatbelts closed during flight" is just a friendly recommendation, some people will invariably unfasten theirs as soon as the sign goes off (some even earlier).

IIRC, the Qantas briefing uses the words "It is a Qantas requirement ..." The emphasis reflects that in the video soundtrack.

Not that it makes the blindest bit of difference. Too many SLF just ignore everything said on the video anyway.

loloflyer 7th Oct 2008 17:32

Why did the aircraft not continue to Perth where there are better medical facilities to treat crew/passenger injuries?

It seems crazy to land at a small town then have to fly some of the passengers on to Perth with the Flying Doctor Service.

In any case, best wishes to all involved.

lomapaseo 7th Oct 2008 17:47


Why did the aircraft not continue to Perth where there are better medical facilities to treat crew/passenger injuries?

It seems crazy to land at a small town then have to fly some of the passengers on to Perth with the Flying Doctor Service.
it's called triage.

Any way you look at it from the ground it's second guessing. Tough decision in the air as a commander who has to rely on info from the cabin.

Finn47 7th Oct 2008 18:27

Perth would have been some 1100 Km further south, which would have meant an hour and a half more for injured passengers without proper medical attention. Better get them on the ground & stabilized and transported later if needed, I guess.

glad rag 7th Oct 2008 18:48

Acceleration limits??
 
What would be the general consensus about positive/negative G figures encountered going from say mild turbulence to CAT??

mermoz92 7th Oct 2008 19:39

I had quite a similar case when flying from Bogota to Paris CDG: all at ounce, during 8-10 seconds, my A340 encountered really huge CAT.

I was Captain on this flight and my wife chief purser...:cool:

It was a night flight, weather forecast on route OK, but very far from my route, there was a heavy tornado.

I felt weather was too calm, when my chief purser told me that all passengers were eating, and then I switched fasten seat belts on, "just in case".

Then happened this incredible CAT I had never met during my 17000 flight hours.

Happily I had only three injured flight attendants.

If seat belts signs had not been swicthed on, I am quite sure I would have landed at Fort of France or Pointe à Pitre, with dozens of passengers very seriously wounded, or even worse.

Two of my three injured cabin crew lost their medic after that flight.

PPRuNe Towers 7th Oct 2008 19:44

Here at the Towers we'd urge very, very careful reading of the brief formal communications from both airline and investigating authority.

The wording is such that we suspect that the aircraft might have taken a cascading trip down through its control laws. Airbus people might want to revisit those quotes earlier in this thread and also the original statements from their primary sources.

Interesting to consider the potential effects of a multiple referencing failure rather than CAT.

Rob

sevenstrokeroll 7th Oct 2008 20:04

Dear Passengers:

You pay my salary, so thank you. But all this about seat belts, trolleys on tracks and that stuff...PUHLEASE:

I've seen PASSENGERS complain about keeping the seat belt sign illuminated. Some disobey the sign and go to the lavatory.

I know of one case in which a 737 hit CAT...the SEAT BELT sign was illuminated...one passenger got up, went to the Lavatory and was thrown violently around BECOMING A QUADREPLEGIC (sp?). GETTING out of your seat with the SEAT BELT sign illuminated also presents a DANGER to the crew and passengers.


Trolleys on tracks...hey great idea...I thought of it over 20 years ago and someone probably had the idea 20 years before that.

So, you want a flight like that...fine, let's triple the price of your ticket.

ON every airliner in the USA there is a sign in front of YOUR face saying to keep seat belt fastened while seated.

I've had FA's get on the PA after I had told the FA's to remain seated telling passengers to get back to their seat in violent turbulence.

PORROHMAN:(and sorry for the mistake earlier) thank you for posting the bit about coffin corner. I know ATP airline captains who really don't have a clue about this. I know airlines who , when given a choice between the 1.25g and 1.375g buffet margins, always tell pilots to go to the 1.25g so the plane can go higher and save fuel.

I have no problem with QANTAS, but I would like to know if there has been any change in buffet margin use and the like.

I am not at all surprised to see NO ONE IS commenting on the bit about watching outside air temps as a clue for CAT. Very few pilots know about...or I should say, MODERN and YOUNGER pilots.

manrow 7th Oct 2008 20:06

Good advice there Rob!

tubby linton 7th Oct 2008 20:14

It has been a while since I flew the A330 but there used to be a procedure that preset some of the flight controls if elevator redundancy was lost.I think it preset the ailerons upwards to counter the pitch up.The pitch up could be quite alarming when you had a subsequent failure.At high altitude you would rapidly be into a stall if you didn't react quickly enough.
I also remember an A340 I think it may have been an SQ one that did a similar manoeuvre when the crew switched off some of the hydraulic pumps when they were trying to balance the fuel!

mermoz92 7th Oct 2008 20:19

You cannot imagine how devastated can be the aircraft cabin with trolleys wine and food flying around.

Nothing to do with the aircraft type I am not so found of.

manrow 7th Oct 2008 20:30

In my experience flight crew pay more attention to the needs of cabin service rather than the less frequent need to restrain passenger movements, so sometimes we get bitten hard!

Modest Pilot 7th Oct 2008 20:40

QANTAS have their FMC's pinned at 1.3g.
You fly attitude in severe turbulance. (airspeed tape usually impossible to read in severe turbulance anyway)
I have never met a QANTAS pilot not aware of the temp drop crossing a jetstream and the implications entering from the cold to warm side we are always crossing them at close to 90 deg. due route structure. (have yet to find a way of 100% compliance of seat belt sign!)

mermoz92 7th Oct 2008 20:42

:ok:manrow, you are right.

But my wife executed my orders....Not like at home.:ouch:

tubby linton 7th Oct 2008 20:49

Trying to fly attitude in an Airbus fbw aircraft is very difficult in normal law as you are commanding a pitch rate.
If the crew had made a poor response the aircraft may have gone into this mode:



ABNORMAL ATTITUDE FLIGHT LAW
A completely different law emerges automatically when the aircraft is in an extreme upset as follows:
* pitch attitude > 50 deg nose up or > 30 deg nose down
* bank angle > 125 deg
* AOA > 30 deg or >-10 deg
* speed > 440 kts or < 60 kts
* mach > M0.96 or < M0.1
The abnormal attitude law is:
- PITCH ALTERNATE with no protection except LOAD FACTOR protection. No automatic pitch trim.
- ROLL DIRECT with full authority
- YAW ALTERNATE
After recovery the flight law reverts to:
- PITCH ALTERNATE law
- ROLL DIRECT law
- YAW ALTERNATE
The aircraft returns to a degraded mode (not normal law as usual) because there is a certain level of suspicion about its ability to control the aircraft (that is how could it have got to the extreme flight state in the first place? The protections should have intervened well before the pitch, bank, AOA, speed and mach limits above).


There was a similar incident in the North Atlantic a number of years ago when an A340 had a speed upset and rapidly departed its alloted level.

thekite 7th Oct 2008 21:05

Pan or Mayday?
 
I have "Mayday"ed twice; once because the smoke coming up the windscreen persuaded me that I was on fire, and the second when I saw so much smoke from a trawler below that it seemed to be on fire.
Technically I should have "Mayday"ed only in the first case as it was "my" aircraft that seemed to be in immediate danger.
The trawler justified only a "Pan", it seems. However the RAAF people were not censorious.
No fire; only smoke in both cases. But who knew?
thekite

sevenstrokeroll 7th Oct 2008 21:18

dear modest pilot:

thank you for that info...the only QANTAS pilot I know of is John Travolta...and I'm sure everyone at QANTAS is better than him.

I respect QANTAS and I'll bet you and I think alike.

When I mentioned the temp thing, I meant it for the other 90 percent of people on this website.

I have a feeling that the crew is not to blame and either a computer glitch or a real doosy of CAT.

ChristiaanJ 7th Oct 2008 21:21

mermoz92, thanks, you answered several of my questions, if only implicitly.

Originally Posted by sevenstrokeroll
Trolleys on tracks...hey great idea...I thought of it over 20 years ago and someone probably had the idea 20 years before that.
So, you want a flight like that...fine, let's triple the price of your ticket.

As an engineer, I don't think it would add that much weight, hence not that much to the price of your ticket.
Look at the seat rails, which IIRC already are supposed to take 15G?

Replace the underfloor stiffeners in the aisle(s) with trolley rails integrated in the structure. Would need new trolley wheels, probably in titanium to take the stress.

I doubt it'll happen, not because it can't be done, but the logistics of the changeover would be horrendous.

And CAT and flying trolleys and injured CC and SLF are (thank goodness) so rare that they still make the 'media' and even PPRuNE, which in itself signifies it's not exactly a common occurrence.... so nothing will be done about it.

Yes I'm a cynic, but also realistic....

Eboy 7th Oct 2008 21:36

"TO ALL PASSENGERS . . . have a plan...IF I HIT BUMPS NOW< WHAT AM I GOING TO DO?"

If a passenger is caught out of his or her seat during severe turbulence, the passenger should drop to the aisle floor, hook an arm through the framework of the nearest seat, and hold hands.

It would not hurt to toss that into the safety video as well.


All times are GMT. The time now is 10:29.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.