Originally Posted by
TJHarwood
Three A320 hull losses between 1988 and 1992, essentially because the flight crew and the aircraft were on a different "wavelength" i.e. unfamiliarity issues.
And Airbus changed their training and the FMC interface accordingly.
Notice any similarities between the Air Inter flight crew's discomfort with having to suddenly make a non-precision landing at Strasbourg and the AF447 F/Os discomfort at having to take manual control at FLT350 (no visual aid, not even moonlight)?
Not really - for a start the AF447 PF doesn't make any reference to discomfort until the roll oscillations start - there's no evidence that he's aware he's doing the wrong thing.
Secondly, while the main technical revision to come from the Strasbourg crash was making the Honeywell FMC display the difference between V/S and FPA select in a more obvious way (by the simple addition of illuminating two zeros to the right of the indicator in V/S mode), the background of the two incidents couldn't be any more different, particularly with regard to human factors. Air Inter dealt exclusively in very short flights with very quick turnarounds - very different to Air France's long-haul operations where the possibility of making up lost time is much easier. This is important because Air Inter in the '80s was placed in direct competition with SNCF's new TGV rail service and therefore the penalties for not making schedule were potentially severe.
In the case of the Strasbourg accident, both the Captain and F/O were experienced pilots, but both had less than 100 hours on the A320 - something which would not be allowed today. When Approach control told the Air Inter Captain that he could not use his preferred approach and would have to land on the reciprocal runway, the report says that his tone of voice on the CVR becomes increasingly agitated, possibly due to a combination of frustration at not making schedule and uneasiness with the fact he'd be making an NPA at night for the first time on this type.
Then we have the fact that ATC gave the crew an incorrect vector, putting them off-course laterally, the aforementioned bad interface design making it possible for them to set a 3300 ft/min descent rate as opposed to a FPA of 3.3 degrees and for the worst bit of luck, a random pocket of turbulence causing the A320 to descend even more rapidly.
What this adds up to was that the situation in the flight deck was tense, but they weren't aware of how severe their situation was until they were a few feet away from the mountain. Compare this to the AF447 case where they were well aware they had problems almost as soon as the PF began overcontrolling, but they did not or could not formulate or action a plan to correctly resolve the situation.
The other big difference is the fact that the Strasbourg A320 was in autoflight almost all the way down to the ground, whereas all evidence indicates that the AF447 A330 was manually controlled into trouble.
AF447 is so depressing because it is 17 years later, and we have another total disconnect between a flight crew and their aircraft.
I'd argue that the more pressing worry in the case of AF447 is the flight crew's disconnect from *each other*. They could see what the aircraft was doing and so unlike the Strasbourg crew they were not "behind the aircraft" as such except for one critical detail, and that was that the aircraft was stalled.
the A330 repeatedly told the pilots it was no longer stalled (and at a critical point for stall recovery at FLT 350 as the CDB re-entered the cockpit)
To be fair to the aircraft, it did tell them it was approaching stall, and then that it was stalled, for nearly a minute before the readings caused the stall warning to trip out. Why did they not respond accordingly, whether the Captain was there or not? Why did neither of the F/O's mention to the Captain that they'd had a minute of stall warning prior to his arrival?
I'm not saying that the stall warning logic doesn't need an overhaul, because it clearly does, but ultimately the warning was there and continued long enough for someone to take notice and do something about it (to say nothing of the oscillating bank angle, rollercoaster pitch changes and the rapidly unwinding altimeter)?
Commercial pressures? Non fici facio, vera prae ceteris - as Davies would say. Get it sorted. Thanks to automation, properly used, there has never been so little excuse for an air crash.....
Emphasis mine, and therein lies the rub!
[ Addition : Air Inter's usual practice, because of the unique way they used their aircraft, was to frequently bat their Caravelles around at 300KIAS+ below 10,000ft (sometimes considerably below!), which tended to play havoc with the GPWS hardware available at the time, and for this reason they received a special dispensation to not have GPWS fitted to their A320s, despite incoming regulations requiring it. Shortly after the accident, GPWS became mandatory and was retrofitted to their fleet. ]