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-   -   AF 447 Thread No. 10 (https://www.pprune.org/tech-log/493472-af-447-thread-no-10-a.html)

roulishollandais 22nd Aug 2012 20:31

@PJ2
What were you used to do with sended ACARS ? Were they all printed in the cockpit ?
Whith the warnings could we listen the printer at 2h10m ?
@ Some AF pilot
What was AF requirement about printing ACARS in the cockpit ?


Originally Posted by PJ2 #1363 thread 9 AF447 16.aug 2012
rh;


Originally Posted by PJ2 #1363 thread 9 AF447 16.aug 2012



Originally Posted by rh
You confirm the ACARS printer was just before the eyes of Marc DUBOIS when he came back in the cockpit... the first thing he could see !

I'm not sure of the point being made here but just to be careful about drawing any conclusions from "the first thing he could see", there would not have been any ACARS printouts as a result of any of the generated maintenance messages or anything else, at that point.






Messages ACARS envoyés à Paris à 2h11m49s (BEA #1)


1.16.2.4 Analyse des messages reçus le 1


er juin à partir de 2 h 10

Les messages reçus le 1


er juin à partir de 2 h 10 ont transité par un même

satellite (Atlantic Ocean West, exploité par la société Inmarsat) et par le réseau
ACARS de la SITA. Les vingt-quatre messages de maintenance bruts sont listés
dans ce tableau :
Heure de
réception


(17) Message


02:10:10


- .1/WRN/WN0906010210 221002006AUTO FLT AP OFF


02:10:16


- .1/WRN/WN0906010210 226201006AUTO FLT REAC W/S DET FAULT


02:10:23


- .1/WRN/WN0906010210 279100506F/CTL ALTN LAW


02:10:29


- .1/WRN/WN0906010210 228300206FLAG ON CAPT PFD SPD LIMIT


02:10:41


- .1/WRN/WN0906010210 228301206FLAG ON F/O PFD SPD LIMIT


02:10:47


- .1/WRN/WN0906010210 223002506AUTO FLT A/THR OFF


02:10:54


- .1/WRN/WN0906010210 344300506NAV TCAS FAULT


02:11:00


- .1/WRN/WN0906010210 228300106FLAG ON CAPT PFD FD


02:11:15


- .1/WRN/WN0906010210 228301106FLAG ON F/O PFD FD


02:11:21


- .1/WRN/WN0906010210 272302006F/CTL RUD TRV LIM FAULT


02:11:27


- .1/WRN/WN0906010210 279045506MAINTENANCE STATUS EFCS 2


02:11:42


- .1/WRN/WN0906010210 279045006MAINTENANCE STATUS EFCS 1


02:11:49
- .1/FLR/FR0906010210 34111506EFCS2 1,EFCS1,AFS,,,,,PROBE-PITOT 1X2 / 2X3 /
1X3 (9DA),HARD
02:11:55
- .1/FLR/FR0906010210 27933406EFCS1 X2,EFCS2X,,,,,,FCPC2 (2CE2) /
WRG:ADIRU1 BUS ADR1-2 TO FCPC2,HARD
02:12:10


- .1/WRN/WN0906010211 341200106FLAG ON CAPT PFD FPV


02:12:16


- .1/WRN/WN0906010211 341201106FLAG ON F/O PFD FPV


02:12:51


- .1/WRN/WN0906010212 341040006NAV ADR DISAGREE


02:13:08
- .1/FLR/FR0906010211 34220006ISIS 1,,,,,,,ISIS(22FN-10FC) SPEED OR MACH
FUNCTION,HARD
02:13:14


- .1/FLR/FR0906010211 34123406IR2 1,EFCS1X,IR1,IR3,,,,ADIRU2 (1FP2),HARD


02:13:45


- .1/WRN/WN0906010213 279002506F/CTL PRIM 1 FAULT


02:13:51


- .1/WRN/WN0906010213 279004006F/CTL SEC 1 FAULT


02:14:14


- .1/WRN/WN0906010214 341036006MAINTENANCE STATUS ADR 2


02:14:20


- .1/FLR/FR0906010213 22833406AFS 1,,,,,,,FMGEC1(1CA1),INTERMITTENT
02:14:26 - .1/WRN/WN0906010214 213100206ADVISORY CABIN VERTICAL SPEED


Analyse du message ACARS concernant les PITOT (BEA#1) :


Analyse des messages


fault


Cinq messages fault ont été reçus par ACARS. Ils sont décrits dans l’ordre dans

lequel ils apparaissent au CFR.
PROBE PITOT 1+2 / 2+3 / 1+3 (9DA) (02 h 10)
ATA : 341115
Source : EFCS2
Identifiants : EFCS1, AFS
Classe 1, HARD
Ce message, émis par le EFCS2 (FCDC2), signifie que les FCPC (ou PRIM) ont
déclenché l’une des surveillances effectuées sur les vitesses : ils ont détecté
une diminution de plus de 30 kt en une seconde de la valeur de vitesse
« votée ». Les trois ADR étaient considérées comme valides par l’EFCS2 au
moment du déclenchement de la surveillance, car le rejet préalable d’une ADR
aurait généré un message fault de classe 2 et l’on aurait donc un astérisque
devant la source. Dans ce cas, la valeur « votée » est la valeur médiane.
Lors du déclenchement de cette surveillance, les FCPC ouvrent une fenêtre
au cours de laquelle ils fonctionnent en loi alternate 2 (voir schéma ci-après).
La fonction de limitation de débattement de la gouverne de direction est
également figée, mais l’alarme associée est inhibée. A la fin de la fenêtre, si
l’écart entre la valeur votée aux deux extrémités de cette fenêtre est de moins
de 50 kt, les FCPC se remettent à fonctionner en loi normale. Autrement, ils
poursuivent en loi alternate 2, la fonction de limitation de débattement de la
gouverne reste indisponible et l’alarme correspondante est générée.
Note : la loi de commande alternate 2 est une loi en facteur de charge en tangage et loi directe en roulis. Seule la protection en facteur de charge reste disponible. Dans certains cas, les stabilités haute et basse vitesses peuvent également être disponibles.





jcjeant 22nd Aug 2012 20:32

@Turbine_D
F-16 SS (from a NASA doc)

The prototype F-16 aircraft (General Dynamics Corporation, Ft. Worth, Texas) used a nonmoving
side stick, which was problematic, because it did not indicate when the maximum command had been
reached (ref. 3). The production F-16 aircraft uses a force-sensing stick with limited displacement
(approximately 1/8 in.). This limited amount of motion significantly improved the handling qualities
(ref. 4). Another fly-by-wire aircraft of the same era, the F-18 (The Boeing Company, St. Louis,
Missouri), uses a conventional center stick with a large range of motion. Although this stick is not
mechanically connected to the control surfaces (with the exception of a pitch reversion mode), it operates
much like a conventional center stick and is well liked by pilots.

TTex600 22nd Aug 2012 20:39


Originally Posted by Lyman
Garbage. Upon loss of Autopilot, PF took controls, and announced it. He then input in two axes, both needing handling, and both correct in direction.

Appears correct to me. Agreed.


Originally Posted by Lyman
From then on, things went South, But don't you dare try to envelop his initial actions into three years of spin...

Troll? That is a stretch.... For three years on, people have been spinning the accident into ever fanciful and flimsy conclusions of PE, whilst defending and lauding the airframe as perfection personified.....

If you're a troll, you and I aren't the only ones. I personally need the airplane to be safe and controllable. It isn't my aim to find the airframe guilty, and I hope and assume you are motivated in like manner. I do want to completely understand how the PF became "startled" and lost awareness, and I'll admit that his actions ended in disaster. PE answers some, if not most, questions, but IMHO, it doesn't answer all the questions. In that light, I appreciate your continual "nit picking".


Originally Posted by Lyman
Hamster wheel under construction, and with odious helpings of wannabe "pilots" waxing scholarly on things that will never be known.

You take the freaking cake. Presumption piled on assumption...

I hope I'm not waxing scholarly on anything. (Clandestino will be quick to point out the correctness of this statement). I do consider you to have actually waxed scholarly on many things. Thank You for doing so. I've learned a lot from you and many others on this forum.

TTex600 22nd Aug 2012 20:51


Originally Posted by DozyWannabe

Originally Posted by TTex600
Why weren't they aware of the continuous trim motion?

They should have been - continuous trim motion in the FBW Airbus design is a given in Normal and Alternate laws.


Originally Posted by TTex600
Why no "trim in motion" claxon, or other indication?

Because the trim is more-or-less constantly in motion, it would quickly become a nuisance. A warning that the trim is exceeding a certain value, on the other hand, would be a viable proposition.

Continuous trim motion is not a design given. Being continuously in trim is.

A warning that trim has exceeded a certain value could be of some value, but an indication of continuous (run away, even if by incorrect stick inputs) would be worth more.

DozyWannabe 22nd Aug 2012 21:03


Originally Posted by TTex600 (Post 7373503)
Continuous trim motion is not a design given. Being continuously in trim is.

I just want to make sure we're not misunderstanding each other here. By "continuous", I don't mean continually moving in one direction, I mean "changing regularly". The way the system works in pitch (as I'm sure you know) in Normal and Alternate is that the pilot (human or auto) commands a flightpath, the elevators move to the required setting to achieve that flightpath, and the autotrim then relieves the elevators. This kind of banal repetitive action is what computers are naturally good at, and because of this the system is constantly correcting itself. Somewhat different from traditional use of trim, but certainly effective.

A warning noise that sounds during "trim in motion" is therefore a bad fit for this design.


A warning that trim has exceeded a certain value could be of some value, but an indication of continuous (run away, even if by incorrect stick inputs) would be worth more.
A warning predicated on limits would be simpler (less complexity = less chance of error) to implement.

mm43 22nd Aug 2012 21:09

DozyWannabe re Trim Wheel

AF447-Thread No.6, Post#120 by RetiredF4 deals with the same subject, and asks a question at the end, to which there appears to be no documented answer.

DozyWannabe 22nd Aug 2012 21:16

@mm43


Originally Posted by GarageYears, Thread 5, post 1796
Manual trim overrides autotrim (micro-switches disconnect the auto-drive if I remember correctly) for the duration of manual input... hold the trim wheel or move it and that prevents autotrim - the computers monitor the trim state during manual trim and on manual 'release', the computer reacquires control from where the manual inputs left off.

(My bold)

Turbine D 22nd Aug 2012 21:59

jcjeant,
Re: F-16 sidestick:
Thanks for the information! :ok:

PJ2 22nd Aug 2012 22:06

Lyman;

Thanks for your comments. With equal respect, may I re-iterate what has been a consistent and largely unchallenged theme since the first few days after the recordings were made public last year and stated by the BEA: - that standard cockpit discipline broke down, SOPs were not executed and CRM was essentially non-existent. Taking control of the aircraft and announcing that, is in itself not a sign of continuing required actions but it is a good start. What immediately ensured however was anything but standard or expected.

At the risk of repeating these things for others, the industry's long-term experience and fundamental principles place these qualities at the very top of airline transport operations as conducted by airlines and their pilots. There is no equivocating on this point - recognizing human factors very early on, these principles are in very large measure what has made this industry so safe over the past three decades.

"By the book" is precisely how airliners are flown, regardless of flight regime, emergency or abnormal. The captain is always free to deviate from such principles and standard procedures but there must be very clear reasons for doing so and only after such deviation is communicated to the other pilot(s) so that everyone knows and can assist.

The only exceptions to this process are extreme emergencies and over the years such circumstances have been well thought out and written into the Emergency and Abnormal SOPs, Memory items and QRH checklists. The rejected takeoff, the GPWS response, the stall warning are a few examples. Most other emergencies must be done "with dispatch" but not haste. The rapid depressurization and emergency descent is one such emergency.

Within very narrow boundaries, the processes are the same throughout the industry: First, ensure the stability and control of the aircraft, ensure the flight path is safe and communicate with other crew members your commands and intentions. Then call for the drills, ECAM actions, EICAS drill or abnormal checklist as the case may be. Fly the airplane while the PM does the work; confirm all non-reversible drill or checklist items before actioning.

So serious is this last item considered to be that in many companies, merely lifting a switch-guard on a switch which controls an irreversible change to aircraft systems, (eg generator disconnect, hydraulic pump shut-down), before confirming that switch with the other pilot, usually ends in the ride being assessed as a failure.

While perfection in SOPs and CRM ops cannot be expected especially under time compression or duress, these procedures are in place to ensure that the threat to the aircraft is minimized, that situational awareness is heightened, that crew coordination is enhanced and problem-solving behaviours thereby, and that actions are taken in a measured and therefore hopefully accurate manner.

None of this behaviour is demonstrated in the recordings. This isn't criticizing the crew...it is what it is and you can't put a blush on it. The PF launched on his own without announcing what the problem was, what he was doing and why, nor calling for any drills or ECAM actions. The PM tried to intervene and read the ECAM but made a mess of it while the PF continued his own course of action. When the PM used the take-over button and began flying the airplane the PF took control right back, neither announcing their actions but just doing it.

There are all manner of reasons, some which demand serious enquiry and response concerning why this kind of scenario unfolded as it did vice the expected procedures that airline transport pilots are trained to execute but that does not alter what actually went on in the first 40 seconds or so. The key in this accident is not determining what the THS did or did not do. Finding out why the crew acted as it did is the key to preventing future LOC and CFIT accidents. As I have offered, this is a performance accident.

Example of Emergency or Abnormal event crew response SOPs:

General Guidance - Standard Emergency and Abnormal Procedures

1. Initial Pilot Actions
A crew member detecting an existing or impending emergency or abnormal condition will immediately inform the other crew members.

Aural warnings will be silenced, and the master warning and/or master caution lights re-armed as soon as the cause has been determined.

Crew members should check circuit breakers and test lights when appropriate. Checking circuit breakers and testing lights is normal crew action and is not listed in the procedure unless there is a specific requirement.

2. Memorized Action Drills
The pilot not flying (PM) will complete from memory the items as directed by the AOM/QRH. In flight, before actuating a switch or control that could result in an irreversible action the PM must first indicate the switch or control and receive confirmation from the PF that the switch or control is the correct one.

On departure, the pilot flying (PF) will call for the appropriate drill at a minimum altitude of 400’ AGL, except as directed by the AOM/QRH.

On approach, the pilot flying (PF) will call for the appropriate drill. The drill should be completed by 1,000’ AGL, or as directed by the AOM/QRH.

Notwithstanding the two preceding paragraphs, prudent airmanship and good judgement will always be the guiding factors for the safest course of action.

3. Checklist Procedures
After the memorized drills have been completed and at a convenient time, the PF will call for the Checklist and Function, i.e. “CHECKLIST - ENGINE FIRE.”

The PM will read aloud all items on the applicable checklist and will call the action as it is checked or completed.

Upon completion of a checklist, the crewmember reading will announce “CHECKLIST COMPLETE”.



SHARING WORKLOAD DURING EMERGENCIES AND ABNORMALS

The general task sharing shown below applies to all procedures.

The pilot flying remains pilot flying throughout the procedure.

The PF (pilot flying) is responsible for:
– Thrust levers
– Control of flight path and airspeed
– Aircraft configuration (request configuration change)
– Navigation
– Communications

The PM (pilot monitoring) is responsible for:
– Monitoring and reading aloud the ECAM and checklists
– Performing required actions, or actions requested by the PF, if applicable,
– Using engine master switches, IR and guarded switches, with PF's confirmation.

REQUIRED MEMORY DRILL ITEMS

Pilots are expected to operate and execute their duties accurately and effectively in accordance with airline approved documents. Any deviation must take place only in the interest of safety and only if and when unusual circumstances dictate.

All pilots are expected to understand all policies, procedures, aircraft systems and operational requirements. In cases where these are identified in the AOM as a ‘Drill’, or in cases where these are not identified as such and are of a time-critical nature, the pilot must have the knowledge and apply the procedure without reference to any publication or material.

INITIATION OF EMERGENCY OR ABNORMAL PROCEDURES

Procedures are initiated on the pilot flying's command.

No action is taken (apart from cancelling audio warnings through the MASTER WARN light) until:
– the appropriate flight path is established,
– the aircraft is at least 400 feet above the runway if a failure occurs during take-off, approach or go-around.

In some emergency cases, provided the appropriate flight path is established, the pilot flying may initiate actions before this height.

INITIAL FAILURE INDICATION
When a failure initially occurs, the ECAM should be applied first.

This includes both the procedure and the entire STATUS review. Only after announcing "ECAM ACTIONS COMPLETED" should the PM refer to the corresponding QRH summary.



roullishollandais;

The way this system works is, these ACARS messages are not printed out on board the aircraft at the time they occur. They are transmitted to the airline's maintenance department in real time (timings as per early discussions on these messages), but are held in memory on the aircraft until the aircraft is parked at the gate, at which time a post-flight print-out occurs, which could and likely would include such ACARS messages. I have seen this many times.

Turbine D 22nd Aug 2012 22:18


Original Post by Lyman
PF took control, and announced it, his inputs were consistent with handling required

Originally Posted by TTex600
Appears correct to me. Agreed.
Hmm, could we compromise by saying: Upon loss of AP. PF took control and announced it.

The rest of the sentence is highly debatable based on outcome...

OK465 22nd Aug 2012 22:48

May I offer a little good natured input about this trim business.....

"Dave?"

"Yes HAL."

"Are you holding the trim wheel Dave?"

"Why do you ask HAL?"

"Just 'checking' Dave."

"Why HAL?"

"Ah yes I feel it now, you have a very gentle touch Dave."

"Thank you HAL."

"I would ask you to please let go of the trim wheel Dave."

"I can't do that HAL."

"I certainly don't want to have do this Dave, but if you continue to hold that wheel I will CUT OFF your Prims, one Prim at a time."

THS movement does not necessarily require an SS movement, NOR will an SS movement necessarily command THS movement!

"Dave...Dave...what are you doing?"

PJ2 22nd Aug 2012 22:59

OK465...during our training, one guy clever with (the really early!) computers rigged up an A340 lesson with, "Daaiiisy, Daaiisy....Give Me Your Answer, Do...I'm half crazy...", etc. Kind of took the edge off the dark, quiet CBT room...

DozyWannabe 22nd Aug 2012 23:01

If I may be permitted a nerdy aside, the level of technology in modern FBW airliners is closer to that of ELIZA than HAL... :}

gums 22nd Aug 2012 23:10

Primitive FBW systems
 
@ Doze and JC:

I beg your pardons, sirs.

The Hornet ( aka YF-17) had a conventional hydraulic control system whereby stick inputs moved valves and the hydraulics moved the control surfaces - same as we had since early 1950's with the F-100, F-101, F-102, F-104, F-105, F-106, F-4, F-111, F-15 and many British and French designs.

Electronic systems "helped" with dampers and such, but the basic control systems were same as those of old.

The Viper was a radical change. Not only was the jet unstable below 0.95 mach, but there were zero mechanical connections to anything hydraulic - no valves, no nothing. Even the gear handle was an electric switch. Only mechanical connection was/is pneumatic bowdown bottle for nose gear and the throttle linkage to an electronic fuel control system ( more electronics) except in BUC ( back up control), when the motor was like the one in the T-33..

To the best of my knowledge, the Hornet still has hydraulic valves that can be controlled by the stick/rudder, with no required FBW inputs when the electrons go FUBAR. The electronics provide some "protections" and such, but just watch a Blue Angel solo pilot yank up at the end of the runway at extreme AoA and pitch rate. That maneuver shows that the FBW is not fully in control. Further, the Hornet is extremely stable in pitch. All my firends that flew the later version as well as the YF-17 say the same thing.

My point is that you can have a great FBW design that can provide "conventional" feel regardless of the aerodynamic stability, or lack thereof, of the platform.

I may be mistaken, but the crew of AF447 learned to fly with basic planes that did not have tons of electronic augmentation or "protections". Kinda like most of us here, ya think? Our cadre in the Viper was very concerned about the newbies that cam right outta pilot training. Turned out that it wsn't a problem. We showed them the limits ("protections") and they did just fine when returning to "conventional" jets. The Viper also had zero cosmic autopilot functions and such. Backup modes were very clear and simple.

all for now....

DozyWannabe 22nd Aug 2012 23:20


Originally Posted by gums (Post 7373707)
My point is that you can have a great FBW design that can provide "conventional" feel regardless of the aerodynamic stability, or lack thereof, of the platform.
...
I may be mistaken, but the crew of AF447 learned to fly with basic planes that did not have tons of electronic augmentation or "protections". Kinda like most of us here, ya think?

But "conventional" feel is only a de facto snapshot in time - it doesn't automatically follow that what's considered conventional now will be conventional in a few decades.

The idea that the airliner flight deck layout that grew out of the postwar years is somehow a natural piloting nirvana is rather limiting in scope, and not supported by the evidence at hand.

gums 23rd Aug 2012 00:15

Conventional now and in the future
 
Good-frigging grief, Doze!


But "conventional" feel is only a de facto snapshot in time - it doesn't automatically follow that what's considered conventional now will be conventional in a few decades.
[Editorial comment: Cockpit layout something for another thread, IMHO. My friend was the captain of the Cali disaster, and the stoopid FMS had duplicate designations for a fix. The two of them realized that somethig was awry when the coupled-autopilot turned the wrong way, but continued their descent after correcting their course. Can talk about that tragedy someplace else.]

Conventional "feel" is what airplanes let you know when the pilot or "system" commands a change in flight path or rate of descent or.....

The basic laws of aerodynamics dictate the response of any disturbance from the trimmed condition. Too fast, then jet wants to climb. Too slow, then jet wants to nose over. It's an AoA function unless the FBW system laws get in the way.

As Doze has reminded me in finitum, our primitive FBW system in the Viper was just that - primitive, simple, etc. It also was a mix of AoA and gee command ( uncorrected for pitch attitude). Control law reversion was really simple - if air data went FUBAR, then the "standby gains" were used and the system used one of two values for control surface deflection and some body rates. AoA still ruled. We never had "direct law" unless in the "deep stall". We never had THS, but the jet tried to get to the trimmed gee if we relaxed pressure on the stick. If the trimmed gee got us to the AoA limit, then the thing followed the AoA limit until airspeed was high enough to get back to the gee command.

The biggest thing for we pilots was that the thing "felt" like what we all had flown for years. Slow, then the thing wanted to nose down. Fast, then it wanted to nose up. We had no change in stick force, but relaxing pressure showed you where the jet wanted to go, and holding a stoopid back stick pressure when at a high pitch attitude and slowing down fast resulted in what happened to AF447.

jcjeant 23rd Aug 2012 00:15


As I have offered, this is a performance accident.
I think we will all agree ..
And on the other hand .. we have the chief pilot of Air France says:
" There was pilots in the cockpit with a maximum skill "
This is indicative of the culture of Air France to not admit that this maximum of "Air France" skill is not enough to cope with such an event of AF447
When we examine the other cases where Air France is involved .. may have thought that those who are out except .. have done with a lot of luck and not by their maximum skill (no respect for memory items or alarms .. etc. ..)

DozyWannabe 23rd Aug 2012 00:37


Originally Posted by gums (Post 7373770)
[Editorial comment: Cockpit layout something for another thread, IMHO. My friend was the captain of the Cali disaster, and the stoopid FMS had duplicate designations for a fix. The two of them realized that somethig was awry when the coupled-autopilot turned the wrong way, but continued their descent after correcting their course. Can talk about that tragedy someplace else.]

As I understand it, it was the paper map that was in error, listing Rozo (the correct waypoint) as "R", when it should have been "ROZO". What the AA965 crew did was type in "R", which brough up a list of matching waypoints, then simply hit "EXEC" twice, which sent them to the Romeo beacon near Bogota. The correct sequence was "R-O-Z-O-[EXEC]".


Conventional "feel" is what airplanes let you know when the pilot or "system" commands a change in flight path or rate of descent or.....
Agreed, but the basic tenet of the FBW Airbus design is that flight deck layout and feel should be common to all aircraft across the range, from the A318 to the A380. Traditional "feel" is an obstacle to that goal.


The biggest thing for we pilots was that the thing "felt" like what we all had flown for years.
Which is undoubtedly a good thing when you're talking about the first generation of a design. Boeing wisely made the 747 behave like a big Cessna, as it was the first airliner of that size.

But once the concept is proven, it makes sense to bring other parts of the technology a step forward. Based on experiments on a Concorde airframe (which was itself reliant on a primitive analogue FBW) with a spring-driven sidestick, Airbus elected to try the technology in a small narrowbody. The A320 airframe design was as conventional as they come (airliner airframe design having been mostly static for nearly four decades), but progression of the control system technology was the target.

While an ostensibly significant difference in flight deck layout, the design had pilot input from the get-go to make it feel relatively intuitive, and if pilot reaction to the control system had been negative, Airbus would have backtracked. Instead they were toe-to-toe with Boeing within a decade.

bubbers44 23rd Aug 2012 00:58

So AF thinks it is a good idea to take an airliner at FL350 and pull up 15 degrees if the autopilot fails???? All our American airliners will stall so we don't do that. I guess theirs do too.

DozyWannabe 23rd Aug 2012 01:07

Not exactly. "Skill" and "ability to cope with a crisis situation" are two very different traits.


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