Did you enjoy 60 Minutes last night?
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Fandangled,
I have never flown an Airbus, but can answer your question. The various protections offered by the flight control system require the computers and sensors to all be working normally.
When the computers are working normally, the system will be in "normal law". It is in this mode that all the protections work.
In the case of this accident however, because of errors in the airspeed sensing, the flight control logic had dropped back to "alternate law". Stall protection is not available in alternate law.
I have never flown an Airbus, but can answer your question. The various protections offered by the flight control system require the computers and sensors to all be working normally.
When the computers are working normally, the system will be in "normal law". It is in this mode that all the protections work.
In the case of this accident however, because of errors in the airspeed sensing, the flight control logic had dropped back to "alternate law". Stall protection is not available in alternate law.
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The computer protections were not available, as the aircraft have reverted, if I remember correctly, to 'direct law' when the computers lost the airspeed input. It basically said "I don't know what's going on - you have control"
If the pilot flying had just kept the thing straight & level it would have recovered after a short amout of time. A friend of mine had the same thing happen & that was the outcome.
It seems that, rather than just maintaining straight & level, the pilot flying decided that full backstick & full power was the thing to do. I imagine that he was taught that if you get into trouble, just pull full backstick & add full power & the computer will keep you out of trouble. There seems to have been no comprehension of high altitude flight & of the fact that you have minimal computer protection in direct law.
Seems to me that it was basically a training issue, much like the fellow in the A300 who used rudder to counter wing drops in turbulence & broke the tail off. Works in a 152 during approach to the stall training, but has no place in jet transport aircraft.
If the pilot flying had just kept the thing straight & level it would have recovered after a short amout of time. A friend of mine had the same thing happen & that was the outcome.
It seems that, rather than just maintaining straight & level, the pilot flying decided that full backstick & full power was the thing to do. I imagine that he was taught that if you get into trouble, just pull full backstick & add full power & the computer will keep you out of trouble. There seems to have been no comprehension of high altitude flight & of the fact that you have minimal computer protection in direct law.
Seems to me that it was basically a training issue, much like the fellow in the A300 who used rudder to counter wing drops in turbulence & broke the tail off. Works in a 152 during approach to the stall training, but has no place in jet transport aircraft.
Last edited by Oakape; 13th May 2013 at 07:51.
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FGD135 said
That statement is incorrect.
There are quite a few levels of sensor degradation that have none to minor to significant effects on flight control protections.
"Stall Protections" aside, a Stall Warning was sounding for most of the event, which seems to have not been given the attention that it should have been.
The various protections offered by the flight control system require the computers and sensors to all be working normally.
There are quite a few levels of sensor degradation that have none to minor to significant effects on flight control protections.
"Stall Protections" aside, a Stall Warning was sounding for most of the event, which seems to have not been given the attention that it should have been.
Last edited by Trent 972; 13th May 2013 at 11:48.
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When the aircraft got very slow, i.e. less than 40kts or 60 kts (if I remember rightly), the stall warnings ceased. Airbus has programed it to do that because at that speed you will be on the ground, according to them. (it seems that they never considered that an aircraft would get that slow in the air)
On the one or two occasions that the pilot flying relaxed the back pressure the airspeed increased (the pitot problem had rectified itself by then) & the stall warnings started again. This caused some confusion & lead the pilot flying to reintroduce full back stick.
On the one or two occasions that the pilot flying relaxed the back pressure the airspeed increased (the pitot problem had rectified itself by then) & the stall warnings started again. This caused some confusion & lead the pilot flying to reintroduce full back stick.
Would never have happened if one of the crew had checked groundspeed on his Garmin 495 or even his iPad or both to get an idea of the aircraft's approximate speed through the air and so disregard the incorrect IAS indication - but that is probably a bit simplistic but would certainly work in my world. In fact have done exactly that when ASI failed on takeoff a few years ago.
Lot to be said for GA.
Lot to be said for GA.
Last edited by On eyre; 13th May 2013 at 08:36.
1/ the A330 went into Alternate Law, hence it trimmed nose up trying to satisfy the Pilot nose up input. That didn't help recovery. Yes no Low speed protections available however a Stall warning given.
2/ the crew didn't need to check their i Pad or Garmin GPS!! They could look at the GS readout on their Nav display or indeed check the GPS Monitor page for all they needed regarding GS and GPS ALT.
All Inertial displays and Engine displays remained correct throughout.
A very scary episode.
2/ the crew didn't need to check their i Pad or Garmin GPS!! They could look at the GS readout on their Nav display or indeed check the GPS Monitor page for all they needed regarding GS and GPS ALT.
All Inertial displays and Engine displays remained correct throughout.
A very scary episode.
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A reasonable presentation from 60 minutes considering the target audience. One aspect I found worthy of comment.... The "experience commensurate with age" profile of the entire crew. 11000 hours for a 58 year old? I am on track for twice that and I have never clocked up much more than 700 hours in a single year.
Is that an Air France thing?
Is that an Air France thing?
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A question for any Captain that trains low time cadet type F/O's in Airbus. How do you know what the right seater is doing with the controls if you can't feel it or see it??
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My check pilot at Toulouse was extremely scathing about Air France ( before this accident)
His words were : " they have crashed every version of Airbus we have sold them"
He referred to the fact that they have different procedures than Airbus standard and re write all the manuals.
Interestingly I have a lot more hours than that Captain (more than double) with 9 years to get to his age.
His words were : " they have crashed every version of Airbus we have sold them"
He referred to the fact that they have different procedures than Airbus standard and re write all the manuals.
Interestingly I have a lot more hours than that Captain (more than double) with 9 years to get to his age.
Forget about training new FO's mate. As a Captain on the Bus I'm never 100% confident to let the FO land in marginal weather no matter who they are because I can never be sure what they are doing with the Sidestick. When I do sense a problem it's probably too late to fix it.
Never had this issue on the 777.
Never had this issue on the 777.
Same scenario occurred on a flight involving a middle eastern airline which cannot be named. Their pilots dealt correctly with the problem, possibly using procedures developed as a result of the AF incident.
Aircraft diverted to Singapore and landed safely.
Aircraft diverted to Singapore and landed safely.
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Some very good posts gents and gentettes (??).
So in a couple of posts just mentioned, and assuming this issue is being repeated around the world regularly with multiple carriers, would I be wrong in saying that some of the hardware design on the Bus's are, to put it bluntly, ****? There seems to be an obvious pattern here, a condition that was latent, but is now well known and still rearing its head.
Obviously pilot skills along with good procedures, good training and good CRM provide layers of defences, which have likely been the saviour of other aircraft that have ended up in similar situations, but I can't help but think that when all the holes line up the design of this technologically advanced machine is dare I say, a killer?
So in a couple of posts just mentioned, and assuming this issue is being repeated around the world regularly with multiple carriers, would I be wrong in saying that some of the hardware design on the Bus's are, to put it bluntly, ****? There seems to be an obvious pattern here, a condition that was latent, but is now well known and still rearing its head.
Obviously pilot skills along with good procedures, good training and good CRM provide layers of defences, which have likely been the saviour of other aircraft that have ended up in similar situations, but I can't help but think that when all the holes line up the design of this technologically advanced machine is dare I say, a killer?