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AF447 wreckage found

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AF447 wreckage found

Old 30th May 2011, 07:36
  #961 (permalink)  
 
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Ok, so now we are clear.
oh, it's been clear before, no problem with that!

however, every indicator other than the AoA gives you secondary information with respect to a stall condition. In a dire situation like this with a tsunami of information, warning, system errors, failing systems, unreliable systems etc rolling over your head, it can be very hard to correctly interpret secondary information. Having the root cause shown to you would shortcut through the cognitive dissonance and help gain correct situational awareness.
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Old 30th May 2011, 07:44
  #962 (permalink)  
 
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An experienced crew would know for their a/c:--

1/ what pitch attitude they must fly AND WHAT IS NOT NORMAL
2/ what thrust setting they must fly AND WHAT IS NOT NORMAL
3/ What noise levels constitute "normal" for their cruise speed
4/ That it is simply not possible to climb 3,000 feet at heavy weights at high altitude quickly ( 7000 fpm apparently ) without Stalling the damn plane
5/ That if they entered the area at a normal speed and power settings then all they had to do was keep the pitch attitude somewhere around 2 deg nose up ( lower wouldn't matter too much, but higher does ) and the thrust around 78 to 80% N1 and they would be ok.

6/ keep the wings level and BE SMOOTH ON THE SIDESTICK.
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Old 30th May 2011, 07:46
  #963 (permalink)  
 
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1. A/c enters cloud with high concentration of super-cooled droplets.
2. Faulty pitot ices over on PF side "freezing" dynamic pressure sent to ADC.
3. Sudden convective event induces a climb reducing static pressure to ADC.
4. PF responds to perceived Mmo excedence with stick back.
5. Static pressure reduces causing airspeed increase.
6. Auto-trim blindly complies with pilot input increasing nose up towards maximum.
7. Repeat steps 4 to 6 until stall....
8. Stall warning stops but comes back on if PF does the right thing.
9. Software has turned off auto trim with stab trim stuck 13 deg up.
10. Software has turned off the bird, just when it would has improved S.A.
11. Checkmate to the software....

In all error chains there's always a bit of man + a bit of machine. But once this kicked off, the man didn't really stand a chance, now did he?

Last edited by Pininstauld; 30th May 2011 at 08:02.
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Old 30th May 2011, 07:47
  #964 (permalink)  
 
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Cool

Hi,

They didn't need an AOA display on their PFD to fly the Aircraft.
I disagree ...
You can't be so affirmative.
Methink the AF447 case is enough to understand that some pilots or aircraft under certain condition need a AOA display.
So ... the solution is to go to the most safe side and have a AOA display
And also needed a stall alarm who sound with no interrupt when aircraft is in stall condition
Save lifes first .. with experienced or inexperienced pilot is a noble task
Foolproof .. as always.

Was in 2006
By Joelle Barthe
Flight Operations Engineer

Quote:
6 Conclusion
An unreliable speed situatio may be difficult to identify, due to the multiple scenarios that can lead to it. Therefore, training is a key element: indeed the flight crew's ability to rapid detected the abnormal situation, and to correctely handle it, is cricial.
In case of any doubt, the pilot should apply the pitch/thrust memory items, and then refer to the QRH to safely fly the aircraft, and to positively determine the faulty source(s) before eliminating it (them).
In addition, to further assit the pilot in detecting the failure and safely fly the aircraft, Airbus has developed the BUSS, which provides a safe flying range indication.
Finaly, to reduze the probally of experiencing unreliable speed situations, on-ground actions, such as comprehensive maintenance and through pre-flight exterior inspection, should be stressed.
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Old 30th May 2011, 07:50
  #965 (permalink)  
 
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well I think it reasonable to expect that this crew might have ignored that piece of information ( AOA display ) just like they ignored 3 fully serviceable BIG ATTITUDE INDICATORS right in front of their noses.
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Old 30th May 2011, 07:53
  #966 (permalink)  
 
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AOA

There is no AOA display in the A330.
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Old 30th May 2011, 07:56
  #967 (permalink)  
 
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Yes we know that thanks.

Actually if you have time ( they didn't ) you can call up AOA in the CMC maintenance pages.
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Old 30th May 2011, 07:56
  #968 (permalink)  
 
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@ Pininstauld: This scenario doesn't work in alternate law...
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Old 30th May 2011, 07:57
  #969 (permalink)  
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Absolutely with nitpcker. Until the BEA tell us WHY the aircraft was climbed so rapidly we are all 'groping in the dark'
Originally Posted by aston
This scenario doesn't work in alternate law
- which bit and why please?
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Old 30th May 2011, 07:57
  #970 (permalink)  
 
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Mainstream media coverage

TO ME IT IS WAY TOO EARLY TO SPECULATE ON A PROBABLE CAUSE BECAUSE ALL OF THESE DISCUSSIONS ARE BASED ON DATA THAT IS SELECTIVELY RELEASED. TOO MANY ISSUES ARE YET TO BE RESOLVED.

Pilot control versus Computer control. Flight into hazardous conditions. Simulator training. Pilot qualifications.

Too many questions. No conclusions.

Way too early for the public to be involved in hip-shot resolutions.
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Old 30th May 2011, 07:58
  #971 (permalink)  
 
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@nitpicker That would be the same as driving on the highway while looking down while shifting gear.
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Old 30th May 2011, 08:01
  #972 (permalink)  
 
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A side comment about AOA indication, valuable info for such operation:
a. It can be measured directly with a vane, but is subject to icing.
b. It can be calculated from INS measurements, generally it is the difference between flight path angle and fuselege pitch attitude.

Its absence was not a factor. A pilot can see the altitude dropping rapidly and the nose pointing up, which is sufficient information to deduct a very high AOA. A push of the sidestick forward would have been enough.

What to me is unacceptable, is an aircraft changing its response to my flight control inputs, due to some laws switching to and fro. In an ideal world it could be regarded advanced, but in the given circumstances it makes the pilot a deputy assistant to the autoflight system, as opposed to the pilot in command.
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Old 30th May 2011, 08:02
  #973 (permalink)  
 
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So in Cruise or other low activity times am I not allowed to look down to my right and use the CMC display on the centre CDU? You might as well remove it then!!

Please re read my post, i did say in brackets that they wouldn't have had time to check it.

Grrr
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Old 30th May 2011, 08:06
  #974 (permalink)  
 
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'Baby' pilot at controls

'Baby' pilot at controls of doomed Air France Airbus | The Australian

HE was one of Air France's "company babies": a dashing 32-year-old junior pilot - and a keen amateur yachtsman - who had been qualified to fly the airline's ultra-sophisticated Airbus A330 jet for barely a year.

Yet despite his inexperience, Pierre-Cedric Bonin found himself responsible for the lives of 228 passengers and crew members on June 1, 2009, when the cockpit of his $190 million aircraft lit up with terrifying and contradictory alarm signals en route from Rio de Janeiro to Paris.
Robert [sitting in the RH seat] shouted with increasing desperation for the captain...
Is this based on info officially provided by the BEA?

The question being asked in the industry is why, given that there was a 50,000ft thunderstorm near the plane's flight path, the youngest of the three pilots, with the least flying time, was at the controls.
“It seems as though they were just clueless,” says Mike Doerr, a former Airbus A320 captain who charters private jets in California. “The response to the invalid speed data doesn't make any sense unless they also had a Mach warning (that the plane was going faster than its mechanical limits).”

So far, there has been no such evidence. At night and in bad weather, however, there is also the possibility the pilots had become disoriented, or did not know which instruments to believe and therefore which warnings to prioritise.

“I don't have any more indications,”

“ Bonin is heard saying on the cockpit voice recorder, his voice still calm.

Doerr said he doubted that American pilots, who typically come from military backgrounds, would have been overwhelmed. “The European airlines select people with virtually no flight time at all and train them pretty much from the ground up,” he said.

“They are 'company babies' who rise up through the organisation. Whereas if you get your experience in the navy or air force, there's an emphasis on trial by fire.”
Thoughts?
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Old 30th May 2011, 08:07
  #975 (permalink)  
 
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AOA indication?

I don't understand the comments regarding the lack of AOA diplayed as being an issue: is it too complicated to substract Flight Path Angle from Pitch?
Pitch-Path=AOA

That is lesson 2 or 3 from any PPL training...
Am I missing something?
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Old 30th May 2011, 08:26
  #976 (permalink)  
 
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AOA

Guess what: The A330 has been retrofitted with a' backup speed scale' (BUSS) in case all three ADC's fail. The BUSS provides a coarse speed reference, based on AOA.
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Old 30th May 2011, 08:29
  #977 (permalink)  
 
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Guess what, to activate the BUSS you need to turn off all 3 ADR's P/B's
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Old 30th May 2011, 08:32
  #978 (permalink)  
 
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I believe that the stall warning alarm on the A330 is derived from some temperature probes (hot-wire flow rate type?) and control surface status? i.e. Incipient stall is calculated. Does the algorithm still work when the aircraft has gone so far out of normal flight conditions? Is it even possible to test it in anything like a real-life situation?
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Old 30th May 2011, 08:38
  #979 (permalink)  
 
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@BOAC

alternate law: I thought there was a line referring to an auto-correction to prevent overspeed. I can't find it anymore. IF the PF behaved that way, it looks like a plausible scenario.

I've been in several deep stall scenario's in normal law in the sim, when preparing training scenario's in different laws. Everytime the stall would be uncontrollable, the high THS setting (max) was the cause.

There is not much THS awareness among Airbus pilots.
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Old 30th May 2011, 08:39
  #980 (permalink)  
 
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@ Lemain. Stall warning on the A330 is based on angle of attack.
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