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AF 447 Search to resume (part2)

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AF 447 Search to resume (part2)

Old 20th May 2011, 09:58
  #1901 (permalink)  
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when humans are confronted by a computer that is either not working, or working in a regime they are not intimately familiar with, they freeze - they go into brain lock

One of the interesting things about pilots (at least pilots from 30-40 years ago) is the tendency NOT to give up in the face of adversity. Furthermore, pilots of that age and earlier were philosophically inclined to press the big "OFF" button and revert to traditional I/F stick and rudder.

I am reminded of an older pilot colleague who, in his 50s, undertook his first heavy jet command endorsement (although he had flown Meteors in Korea). He was finding it all a bit heavy going until a mid-way through sim session involving limited panel type flying .. he emerged with a grin from ear to ear .. "it's just like a real aeroplane, mate !" Needless to say, having observed that it (DC9) was not much different to a DC3 .. he had, thereafter, no problems.

It may not be the case these days with the emphasis on button pressing .. but a freeze response certainly wasn't endemic in past times.
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Old 20th May 2011, 10:04
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Originally Posted by takata
Beside, there is few differences between combat aircraft flight envelope and airliners ones, as far as pure "flying abilities" are concerned.
Originally Posted by Nick L
Ultimately the Airbus aircraft are aerodynamically conventional, so they should be stable and well within a pilot's ability to fly, even without computer compensation.
+1.
Let's no get confused : some military aircrafts (fighters, like F-16, M2000... but also bombers like the F-117 & B-2A) use the FBW and are inherently unstable aerodynamically.
- This instability prevents the flight without the assistance of computers.
- This instability is chosen for various factors : better hard turn performance (fighters), better stealth (B-2 : flying wing, no VS)
On the other hand, and AFAIK, civilian aircrafts (for pax) MUST be stable aerodynamically (certification). Which means that sould the computers not being available, the pilots are able to fly without them. That's the purpose of the other-than-normal-laws of the Airbus FBW, isn't it ?

I stand to be corrected, should I have forgot/misunderstood some important point.
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Old 20th May 2011, 10:15
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Hi JT,

All very true.

In the past we were familiar with the way conventional aircraft "felt" with the autopilot out. We knew how to trim precisely for speed and power changes. But there is less familiarity with FBW aircraft. The only time I've "felt" Alternate or Direct Law is in the simulator. When the computers get false air speed inputs, and the FBW logic downgrades, the best time to practice is not in the middle of a thunderstorm.
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Old 20th May 2011, 10:17
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Plasmech,
The captain, whose body was recovered in June 2009, is thought to have not been in the cockpit.

Three of the four seats in the cockpit were retrieved; captain's seat. co-pilot's seat (that is how the BEA identifies the seat), and "fourth occupant's seat". The fourth occupant's seat is a jump seat. The main jump seat is the third occupant's seat, which apparently was not recovered (yet).

It is presumed that the two bodies recovered were sitting in two of those three recovered seats.

The Le Figaro article used the French word "sécurité" with respect to Air France procedures. As has been subsequently learned by non-native speakers of French, sécurité can be translated as either safety or security. Similarly, the French word "sûreté" can be translated as either safety or security.

I have seen sûreté and sécurité used in the same sentence, so the French must distinguish between the two with respect to meaning. French is not my native tongue by a long shot, but based on the following from Les Aeroports Francais, sûreté is used on the ground before boarding, and sécurité is used when in the air.

Sûreté

Soumettez-vous de bonne grâce aux contrôles de sûreté : il y va de votre propre intérêt ! Ces contrôles sont effectués avant l’arrivée en salle d’embarquement. Les bagages à mains doivent passer dans un appareil de contrôle radioscopique. Sur un écran, l’agent de sûreté visualise leur contenu. Vos bagages à main peuvent également faire l’objet d’une inspection visuelle ou d’une visite manuelle.
Sécurité

A bord de l’appareil, des instructions concernant les mesures de sécurité vous seront exposées par le personnel navigant commercial (hôtesses et «stewards») au moment du décollage, conformément aux obligations édictées par la réglementation internationale : renseignements sur l’usage des ceintures de sécurité, des gilets de sauvetage, des masques à oxygène et l’emplacement des sorties d’urgence. Ces instructions sont reproduites sur un feuillet placé dans la pochette située devant votre siège.
A lesson from Egyptair 990 was never leave a single pilot alone in the cockpit.
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Old 20th May 2011, 10:22
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When I read instinct, I'm reminded of what Wolfgang Langewiesche calls "seat of the pants" flying. I think it is largely accepted to be irrelevant in modern day piloting.
Sullenberger - US Airways Flight 1549

Burkill - BA Flight 38

Didn't both these captains "instincts" have a result in the outcome of their plights.
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Old 20th May 2011, 10:34
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- let's not go there, shall we ? Nice lasses but not appropriate for the thread .. JT -
however in-appropriate, it may be extremely relevant to this thread!

perhaps it would be better to suggest that there is a video on stupidvideos.com of a air france cabin crew doing a bit of a moulin rouge in the cockpit for the benefit if the flight deck. And let other decide if they want to look at it. You want something to take your eyes off the weather radar, that will do it!
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Old 20th May 2011, 10:59
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DJ77,
Of course I have no doubt that all the software was carefully studied and checked in all possible ways but sh*t happens. I agree this may be far-fetched and stand ready to be guillotined.
Do you still have your head attached to your neck ?

Probably not as you'd have all by yourself and svarin proven how and why that airplane plunged to the depths of the South Atlantic Ocean.

mm43's post and link should have given you some consolation.
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Old 20th May 2011, 11:07
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Matelo,
Sullenberger - US Airways Flight 1549
Let's not confuse different aspects of flying here, shall we ?
What Captain Sullenberger demonstrated was superior airmanship, decisive and quick decision making and an outstandingly good knowledge of his aircraft, down to the peculiarities of the final attitude with a Flap 2 configuration.

If you go to "the seat of the pants flying" aspect, he could have probably done better in his final speed management. I'm certainly not going to criticize any aspect of his situation management, but that aspect of the incident is, if anything , proof that old fashioned *butt cheek instinctive flying* is dead.
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Old 20th May 2011, 11:37
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Lemurian,

Your illuminating clear-sightedness really enlightens this thread, thank you.
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Old 20th May 2011, 11:46
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JT
Beg to disagree with your remark of 30 yrs ago.

Papa India - stick push went off three times but was dumped because it was not believed.

No one did a basic aircraft configuration check and the Trident hit the deck with the droop still retracted.

It all comes down to pilot ability and training.
We were trained to not trust the pusher and dump it.

Pitot/static failure training was also ignored.

A BAC 111 had a multiple failure which was caused by water trapped in the static/pitot lines resulting in simultaneous overspeed and stall warnings.

A fighter was scrambled to fly the approach with the aircraft whilst the skipper flew pitch power which wasn't trained in the company at the time.
Management accused him of mis reading the instruments (and being a idiot) until the source was found.

In my opinion the training department and management were to blame - again lack of ability and training.

ITCZ - I operated some of the first europe RIO direct flights.

We had a double crew - six pilots and two engineers.

No captain in their right mind (poss FO as well) would have left the flight deck for the transit through the nasty part.

It could last 1/2 hour or four hours.

Weather radar quality varied between good and absolute cr@p.

Radar turbulence detection worked on amount of water in the cloud - I have had severe turbulence in a relatively dry part of a CB.

Our transits were always in the early hours of the morning when we were dog tired and should have been sleeping.

Whether or not, and I suspect not, the crew were trained and in current practice of flying an aircraft manually in turbulence with instrument failures they faced a monumental task.

If this was the scenario and it is still not sure then why do we have two crew operation?

Why do we not have satellite radar imagery?

Why do we not have full time communications?

Why do we not have wing tip collision avoidance systems?

Cheapskates and industry leaders who put profit before moral responsibility.

I leave open the debate about substandard aircraft systems and sensors until we (if) eventually find the truth.
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Old 20th May 2011, 12:01
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Allow me to go to the very basics.
There are only two things that can change the speed of an airplane. "Nose" and Thrust.

If you have indication of over (or under) speed and your engine settings (EPR, N2, whatever) are within parameters, something is "wrong" with your "nose".

The attitude indicators will show clearly if the "nose" is up or down, no big deal.

Still talking basics, if your power settings are OK, AoA OK, but airspeed indicator goes crazy it is easy to any pilot to realize he is having a wrong airspeed indication.

Now, allow me to scape from basics. The computer is flying the airplane, receives a "wrong" airspeed indication. Is the computer capable to do this simple cross-check (Power settings x pitch) before reacting?
To what I understand, the computer will react immediatly and possible wiil make a wrong input, if he got a wrong airspeed indication.

Here is where a "Human Pilot" can beat a computer logic, and thats why he should be able to shut down the computer in a split second.

Combine all this inside a CB, again the pilot knows that if the nose is up, it is probably going down shortly. Thats why he is trained not to "fight" the airplane in turbulence. On the other hand, the computer is "trained" to "flight" the turbulence to the extreme of his capacity, and then handle the airplane "upside down" to the pilot.

If in the early days CBs had to be avoided, nowadays they should be specially
avoided.
Human Pilots can handle a CB, computers can't...
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Old 20th May 2011, 12:07
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Your illuminating clear-sightedness really enlightens this thread, thank you.
Better than agenda-charged malicious theories on total loss of control in case of an ADIRU failure, isn't it ?
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Old 20th May 2011, 12:26
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Lemurian, I never said they were "the seat of the pants flying", I said instinctive actions aided their plight.
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Old 20th May 2011, 12:28
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We Still Need Exceptional People.

The first error is trying to define human error.
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Old 20th May 2011, 12:28
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Still talking basics, if your power settings are OK, AoA OK, but airspeed indicator goes crazy it is easy to any pilot to realize he is having a wrong airspeed indication.
Rob, I think that part of the concern is that the pilot in the A330 does not have an AoA display as part of instrument display. (That is my understanding based upon a number of posts and explanations on how AoA figures into the FBW and protections features in various Airbus, and Boeing) airliners.
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Old 20th May 2011, 12:39
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MATELO,
I never said they were "the seat of the pants flying", I said instinctive actions aided their plight.
In this case, I apologize, but still, if we opened a thread on Capt Sullenberger's actions on that day, we'd discover that they were the results of an exceptionally disciplined mind.
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Old 20th May 2011, 12:45
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SaturnV
The Le Figaro article used the French word "sécurité" with respect to Air France procedures. As has been subsequently learned by non-native speakers of French, sécurité can be translated as either safety or security. Similarly, the French word "sûreté" can be translated as either safety or security.

I have seen sûreté and sécurité used in the same sentence, so the French must distinguish between the two with respect to meaning. French is not my native tongue by a long shot, but based on the following from Les Aeroports Francais, sûreté is used on the ground before boarding, and sécurité is used when in the air.
Just my two (euro-)cents as a french native: the term "sûreté" generally addresses matters of deliberate jeopardy: theaves, enemies of state, terr¤rists and so on. This is illustrated by the term "sûreté de l'Etat", that translates to "State security". Generally again, the term "sécurité" addresses dangers not resulting from deliberate action: we use the term "ceintures de sécurité" in cars and planes ("safety belts").
Thus, most often, "sécurité" translates to "safety" and "sûreté" translates to "security", but it's true that both terms are interchangeable to some degree: e.g. the established term "Autorité de sûreté nucléaire" (nuclear safety Authority), which primarily addresses nuclear accidents, not deliberate attacks against nuclear plants.
Espère ceci aide.
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Old 20th May 2011, 13:01
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JP:

At least Engligh and French share, from their Latin roots, ambiguitatem. We are linguistic third cousins twice removed, are we not?
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Old 20th May 2011, 13:04
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BEA posted this summary of the sea search operations on Monday already, but I haven't seen it mentioned here before:
http://www.bea.aero/fr/enquetes/vol....16.05.2011.pdf

Most interesting in my opinion are fig.5 and fig. 6. One is a diagram of nine marker buoys and their drift paths, from an experiment made in June 2010. Look at those crazy loops! I guess that is what persuaded them to abandon any predictions about the crash site based on the location of floating debris.

The other is a map used for planning phase 4 of the search, indicating the most likely places to find the wreck. It is based on the assumption that most (but not all) areas already covered by sidescan sonar need not be searched again, and (in contrast to phase 3) that the pingers were probably just not working.
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Old 20th May 2011, 13:05
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Lemurian, Sully's successful actions were not solely the result of a disciplined mind (though I agree that was key) but also the outcome of he and his copilot being experienced pilots.

I think "instincts" is being used to apply to both understanding, practice, and experience in flying. Sort of like the way an experienced golfer selects a particular chip or pitch shot in the region near the green. Without a lot of experience and practice of what would or would not work, the choice may not fit the situation of trying to get the ball into, or near, the hole.
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