Afriqiyah Airbus 330 Crash

[737Jock]

Blind pew you seem to be an old fart that doesn't realise that nose forward and full thrust have led to some very frightening situations. Such as not being able to unstall the aircraft, secondary stalls etc etc.
Which is also the reason why people might reduce the rhrust to idle -> it provides an immediate nose-down effect.

Was this correct in the AF situation, I sincerely doubt it but I don't fly A340 nor have been trained by AF. Was it horrible? No they were in normal law.

And blind pew talking about airmanship/skills etc etc to defend your argument for your suggested stall recovery (which is outdated)....... But then I wonder: Why did this person even stall if those qualities are so greatly developed???

[blind pew]

Jock - old fart?

Of course that goes without saying.
But I guess that you have never flown DC8s which had a huge pitch - power coupling. Nor got bored with teaching aerobatics and mountain flying.
Then I would also guess that your knowledge of physics isn't the best.
The stall/ terrain equation is about managing energy.
Hydrocarbons need to be converted to potential and kinetic energy.
A stalled aero foil is way on the backside of the drag curve - one needs to get energy into the equation - either from potential - IE throw away altitude or by converting HC to thrust.
The most critical phase is close to terrain so the obvious solution is pitch down and full power - the later takes TIME which you might not have enough of. If the pitching couple is too great then you can always reduce it.
But if you had flown something like a DC8 or a 707 you would know how critical the trim is and you would be winding it forward at the same time as you push the stick and throttles forward.
At altitude the power pitch couple is far less (back to physics again) and you have more time anyway.
Then we have time for the niceties of configuration and limits.

The A340? Story about shutting an an engine down is NOT true.(from a senior airbus pilot yesterday - although his reply was rather more colourful).

Those readers of my generation would remember the huge wheels with a white mark and a klaxon which drew your attention whenever they spun. The memory drill to inhibit their movement in the event of a runaway because of the (true) stories of what could and did happen.
Sensible use and observation of the trim was part of airmanship that old farts of my generation were taught.
But then again it took me 300 hours and two years to get into the RHS which the powers that be considered to be marginally enough experience (quite rightly so) and that was on a three crew airliner.
But then again we was pilots and play station hadn't been thought of

[Capn Bloggs]

Stick fully forward and apply full thrust? No, that's from the guys that think everything flies the same or havn't had the benefit of up to date training/test experience, or accident/incident investigation, in modern jet aircraft.

deptrai listed the correct procedure.

No for all types, he didn't. That's only a template (obviously biased for "modern" underslung engine types) and is not the correct procedure in the many cases where the engines are on same level as the C of G.

[BOAC]

What is this modern fad for making all flying into a 'corn-flake packet cut-out' kiddies' template?

Firstly, 99% of all airline 'stalls' are not stalls but stall warnings, because that is where you 'recover' in the sim and I'll wager most pilots will for real.

Secondly, as Pew knows, if you are 20kts below Vref at 100ft and you have a stall warning, lowering the nose, levelling the wings and thinking then about applying power will guarantee a touchdown earlier than you hoped and probably not too good.

All this froth came about because silly trainers got in their minds to INSIST on minimum height loss in stall recovery, including at high altitude. There is no such thing as a 'standard' stall recovery - you do what is needed. If the wing is STALLED you MUST reduce AoA regardless. If it is power you need at low altitude you apply it, in a sensible amount, ready to reduce it if you have the 'underslung' looping tendency, but power you will need. If you are at altitude, you can trade height for speed. As with many other facets of 'committing aviation', some understanding and realisation of the situation is needed rather than a blanket response.

[737Jock]

Hmm blind pew, you are the one suggesting one recipe for every situation. Which really suggest that you have a very limited idea of physics!

No I had the pleasure of flying 737's which has a huge pitch power coupling...

I'm not impressed with your CV, sorry buddy! But I have met guys with loads of experience, in various areas including fast jets, who are absolute crap!

Again the name of the game is to not get anywhere close to a stall, once you are in a stall in a commercial airliner you ****** up big time! Its no use to start fending with airmanship or manual flying skills at that stage, cause you just proved their not all that!

In the airframce case they weren't close to a stall. But due to the aerodynamic build of the aircraft the horizontal tail of the aircraft is actually a bit too small. Like an MD-11!
Smaller tailplane is more efficiency, and this is no problem under normal circumstances. However it also means that you might not have enough pitch authority at low speeds, to counter the pitch up effect of underslung engines at full T/O thrust.

Which is why the current manufacturer procedure is to break the stall with pitch, and gently add energy through the engines. So yes you might loose a bit more in recovery, but not nearly as much as you would lose in a secondary stall. And if you happen to find yourself in this situation at 100ft, well pray to god and and add thrust as quickly as possible. But personally I have never seen a stall recovery from a full stall in a jet in less then 100ft with full t/o thrust!
Did you happen to ask the senior airbus guy about this manufacturer procedure as well? Or did selective memory trouble you? Or maybe the guy is a figment of your imagination?

Sorry buddy, but I told you the A340 story about shutting an engine down was hearsay. So the colourful response aside, you are really barking up the wrong tree!

[blind pew]

Jock - twaddle
But due to the aerodynamic build of the aircraft the horizontal tail of the aircraft is actually a bit too small. Like an MD-11!
So the frogs and the yanks certify aircraft with "tails" that are too small?
Gosh you obviously know as much about aerodynamics as you do physics.

[737Jock]

Stall Recovery
Applicable to: ALL
As soon as any stall indication (could be aural warning, buffet...) is recognized, apply the immediate actions:

NOSE DOWN PITCH CONTROL APPLY
This will reduce angle of attack

Note:
In case of lack of pitch down authority, reducing thrust may be necessary.

BANK WINGS*LEVEL

When out of stall (no longer stall indications) :
THRUST INCREASE*SMOOTHLY*AS*NEEDED

Note:
In case of one engine inoperative, progressively compensate the thrust asymmetry with rudder.

SPEEDBRAKES CHECK*RETRACTED
FLIGHT PATH RECOVER*SMOOTHLY

If in clean configuration and below 20*000*ft:
FLAP 1 SELECT

Note:
If a risk of ground contact exists, once clearly out of stall (no longer stall indications), establish smoothly a positive climb gradient.

My bold, this is directly from the A320 QRH. Clearly they considered terrain impact.

Take it up with the manufacturer blind pew... Or the senior airbus guy
Obviously they should talk to you!
But any crew who allows their aircraft to stall, had better follow the manufacturer procedure or they will be hung, quartered and drawn.

TOO small may be overstated, but there certainly isn't any slack in modern aircraft design. And insufficient pitch authority is not unheard of unfortunately.

[BOAC]

In the airframce case they weren't close to a stall.

- yes, jock - twaddle. What do you call 40 degrees AoA?

[blind pew]

BOAC - obviously secondary effect of too small a Horizontal tail

[737Jock]

40 degree aoa?

http://www.bea.aero/docspa/2012/f-zu...f-zu120313.pdf

Aren't you thinking of AF447?

The A340 incident reached a pitch of 26 degrees and an IAS of 130kts... Thats not a stall! And they never went below 2000ft!

Lets not let that sort of detail or actually reading what is being discussed get in the way of a good trashing however!

Maybe you guys should date... something like this would/could never happen to you I guess.

Unfortunately you are retired, so aviation is left with mere mortals. And therefore the manufacturers had to change the stall procedures...

[BOAC]

Yup - misread your posts- sorry.

[737Jock]

Thanks BOAC.

[blind pew]

Know rather a lot about incorrect and foolish stall training as it became a personal interest after my best mate died in Britain's worst stall accident.
Ill thought out proceedures, incorrect training, maintenance, back dated paperwork, apparent amnesia at the inquiry...the list goes on and YET some of the practices continued for another 14 years.
Witnessed a couple of transient stall warnings which were put down as false but turned out otherwise after the FDRs had been downloaded.
Then I taught stalling and spinning for 15 years including Occasional demos below 1000ft.
And last month I booked up for a course to stall my paraglider - over a lake with a rescue boat and medics - just incase I get it wrong.
So whilst I might be an old fart I do have a little bit of experience and still believe that you teach one basic automatic recovery - stick forward and full power followed by the niceties and evaluation.
I was taught that in 1970 and the following year found myself upside down in a Baron with my nav kit on the ceiling following a clean 1G stall - worked perfectly.

[tubby linton]

Jazzhands, the A343aircraft was only on Flap 2 and was around 163kt before the pitch up. The speed to me sounds about right for F speed but obviously it varies with weight. F in approach config is 1.3 *VS1g which gives a stall speed of 125kt but the g may have been slightly higher as the aircraft rapidly pitched up.
Jock you have quoted the stall recovery procedure but as the A343 was in normal law it would of course have gone into alphaprot so your procedure would not have been applicable.
The report seems to lack a lot of detail. I could find no time scale only a distance from the threshold.There is also sparse information about the AP/Athr modes at specific times. I wonder what happened to the crew involved?

[737Jock]

Wow you stalled a baron, and a paraglider...
And you had a mate who died in the worst stall accident... AND you taught stalling and spinning in piston aircraft...

Obviously you are the expert on stalling a 300ton jet! Please contact airbus and Boeing ASAP I'm sure they need your expert consultancy on the matter!

[737Jock]

So whilst I might be an old fart I do have a little bit of experience and still believe that you teach one basic automatic recovery - stick forward and full power followed by the niceties and evaluation.

Exactly what they did in the G-THOF 737 incident.
Turned out that stick forward was not enough! They required extra trim nose down as the elevators do not give enough pitch authority to counter the pitch-up effect from underslung engines.
On top of that because maximum thrust was asked, full power as you say, combined with a cold day: the delivered thrust exceeded the rated thrust.
This excess can be too large for the designed pitch authority.

And they started recovery before the stall warning! Thus airflow over the tail was greater then what would have been the case during a stall.

There is no single recipe for recovering from a stall in a jet. You need to be very careful with thrust during recovery.

[737Jock]

You also might want to read this report on the airbus accident in Perpignan:

http://www.bea.aero/docspa/2008/d-la...a081127.en.pdf

2.1.5 Loss of control
When the stall warning sounded, the Captain reacted by placing the thrust levers in the TO/GA detent and by pitching the aeroplane down, in accordance with procedures.
The nose-down input was not however sufficient for the automatic compensation system to vary the position of the horizontal stabilizer, which had been progressively deflected to the pitch-up stop by this system during the deceleration. The Captain controlled a left roll movement, caused by the stall. The aeroplane’s high angle of attack and the roll movements generated asymmetry, and a speed variation between ADR 1 and 2 appeared. This increasing divergence caused a rejection of the three ADRs by the FAC then the ELAC. The flight control system then passed into direct law. It is likely that the crew did not notice this due to the emergency situation and the aural stall warning that covered the warning of a change of flight control laws. The Air New Zealand pilot, by saying “alpha floor, we’re in manual” likely considered that the alpha floor function had triggered and that in fact the autopilot had disconnected.
The aeroplane rapidly regained speed under the dual effect of the increase in thrust and the pitch-down attitude. Under the combined effect of the thrust increase , the increasing speed and the horizontal stabilizer still at the pitch-up stop, the aeroplane was subject to pitch-up moment that the Captain could not manage to counter, even with the sidestick at the nose-down stop. The exchanges between the pilots at this time show that they did not understand the behaviour of the aeroplane. In particular, the aeroplane’s lack of reaction to the nose-down control input did not draw their attention to the position of the horizontal stabilizer and the loss of the auto-trim function.
The aeroplane attitude increased sharply and its speed dropped to the point that rendered it practically uncontrollable, the flight control surfaces becoming ineffective due to the low speed and the high angle of attack. The aeroplane stalled again, this time irrecoverably, bearing in mind the aeroplane’s altitude and without any crew inputs on the trim wheel and the thrust levers.
The loss of control was thus caused by a thrust increase performed with a full pitch-up horizontal stabilizer position. This position and the engine thrust made pitch down control impossible. It should be noted that the PF made no inputs on the horizontal stabilizer nor reduced the thrust and that the PNF did not intervene. This seems to indicate that none of them were aware that the automatic trim system, which relieves the pilot of any actions to trim the aeroplane, was no longer available. In the absence of preparation and anticipation of the phenomenon, the habit of having the automatic trim system available made it difficult to return to flying with manual trimming of the aeroplane.
It should be noted that even though, from a regulatory perspective, the limitations on duty time and flying time were respected, the length of time that the two XL Airways Germany pilots had been up, since waking before 4h30 for positioning, until the accident at 15 h 46, may have altered their performance during the flight, especially during the approach phase.

Due to the position of the stabilizer at full pitch-up and the pitch-up moment generated by the engines at maximum thrust, the crew lost control of the aeroplane during the increase in thrust.

And one of the recommendations that led to our new stall recovery procedures:

4.4 Approach-to-Stall Recovery Technique and Procedure
When the stall warning sounded, the crew reacted in accordance with the procedure for recovering from an approach to stall by applying full thrust to the engines and by trying to decrease the pitch angle. The moment generated by the application of full thrust to the engines and the pitch-up position of the stabilizer made it impossible for the crew to be aware of the situation and to recover control of the aeroplane. In addition, the manual use of pitch trim, which is not included as a reminder in the approach-to-stall procedures, only occurs very rarely in operation and occasionally in training. Several investigations undertaken following accidents and incidents (including that mentioned in 2.4) tend to call into question the procedures relating to approach-to-stall techniques for all types of modern aeroplane. Studies are currently under way with a view to improving these procedures.
Consequently, the BEA takes into account these elements and also recommends:
€ That EASA, in cooperation with manufacturers, improve training exercises and techniques relating to approach-to-stall to ensure control of the aeroplane in the pitch axis.

[lederhosen]

Come on 737Jock play the ball and not the man. You can read Blind Pew's book (easily findable with the search function) which tells us plenty about his credentials to comment, Trident, VC10, DC10 etc.

Your information in the two later posts is interesting. The Perpignan accident was of course a test flight where the aircraft did strange stuff for multiple reasons. The Icelandair 757 go-around in Oslo some years ago is another example of gyrations on go-around with a normal aircraft.

I raised the issue of the AF flight because of its parallels to Afriqiyah: wide body airbus, early morning arrival, misflown approach, confusion during the go-around. Its fine to disagree but lets treat fellow professionals as we would wish to be treated and get back on thread.

[blind pew]

Thanks lederhosen

Jock if you had read my post re stall recovery and what I was taught to do you would have discovered that elevator trim position was part of the scan and that if the beast doesn't do what you want it to do then you use other means such as trimming forward, reducing thrust, changing configuration.
Mate witnessed a mid air between a glider and a free fall parachutist...(another inquiry where false statements were made).
The glider pilots could not get out due to high G loads after wing tip sheared off.
In desperation they tried everything including airbrakes which altered the spiral dive and survived bailing out at 400ft.
The stall my mate got killed in had many causes - the principal was suppressing previous events, followed by incorrect stall recovery teachings, lack of understanding, general incompetence, fear of the aircraft and bullying.
A recent discussion with someone far better qualified than I am who had witnessed simulator crashes when "thrust as required" was not enough and too late said the new proceedure was the result of lawyer influence. He also insinuated that no one had the gonads to speak out.
Back to the old ways of everything is pilot error.
And as general interest re a couple of the stall warnings that I witnessed they were on the Trident which approached well on the backside of the drag curve at a higher speed than most aircraft of the era - we burst lots of dunlops as well - it was also due to a sluggish early autothrottle which we were not allowed to take out except in the event of an engine failure and probably in severe turb such as Heraklion or Gib with a southerly gale.

[deptrai]

said the new proceedure was the result of lawyer influence

interesting rumour. I don't have any inside knowledge. What I see is that manufacturers reacted to multiple wake-up calls, after incidents and accidents which we have all read about, by revising their procedures, and the FAA bases their guidance on collective industry knowledge. Boeing states:

"Most approach to stall incidents have occurred where there was altitude available for recovery. The incidents that progressed into accidents often occurred because the crew failed to make a positive recovery when the stall warning occurred, the condition progressed to a full stall, and the airplane impacted the ground in a stalled condition. For this reason, emphasis has shifted from a recovery with minimum loss of altitude to reducing the angle of attack below the wing stalling angle to complete a positive and efficient recovery."

IFALPA also revised their best practices guide. I don't think it's a lawyer conspiracy.

For me, "thrust as needed" translates into "apply airmanship here", and all common sense precautions apply, such as when approaching a stall, don't forget to monitor altitude, and don't fly into the ground (which is conveniently repeated multiple times in the FCOM). There is never going to be any one-size-fits-all-aircraft-and-situations-procedure, FAA guidance is biased towards modern large transport jets, and a majority of incidents, and I am sure in some particular situations aggressive increase in thrust will be needed.

Fact remains that for swept-wing aircraft there is generally a tendency to increase AoA when stalled. Stall starts at the trailing edge of the the wingtip, and as it progresses back up the wing, the aerodynamic center is moved forward, raising the AoA. The angle of the aerodynamic force shifts aft, resulting in rise in induced drag, further increaseing AoA (this is nothing new, and there are lots of details in the still excellent "Aerodynamics for Naval Aviators" ). Since all pilots learned recovery procedures during basic training in a very different aircraft, some may not be fully aware of the characteristics of their current aircraft, particularly in unusual situations. And when they then agressively increase thrust, with the engines below CG, there can be a significant pitch effect, and they may just worsen the AoA problem. Which makes particularly little sense when there is ample altitude available. Getting this information out seems sensible to me.