AMR 587 Airbus Crash (merged)
Join Date: Jul 2000
Location: UK
Posts: 58
Likes: 0
Received 0 Likes
on
0 Posts
Just a few other thoughts,
Is there currently training within your organisation on large aircraft upsets? Perhaps there should be a greater emphasis placed upon upset training considering the increasing congestion of terminal areas and airways - free flight could lead to an altogether interesting situation than there has been in the past.
Unlike the pitch and roll axes, I am unaware of an aircraft that provides protections in the yaw axis. Should this be addressed by all manufacturers?
From Capt F...... "Should we all have been expressly warned of this? Well, my car handbook doesn't spell out for me what would happen if I decide to slam the shift into reverse at max speed, because they don't believe I would want to do that, and it has been the same for the aircraft builders. Of course in a country that tells you your coffee is hot, things may be different."
Lastly and unfortunately in the western world, act of god or 'accident' has disappeared from the dictionary. There must be blame - else no claim, unfortunately to human is to err.
Perhaps we should do as the journalists say and give up flying and travel by rail..........now there is a big can of worms.
Is there currently training within your organisation on large aircraft upsets? Perhaps there should be a greater emphasis placed upon upset training considering the increasing congestion of terminal areas and airways - free flight could lead to an altogether interesting situation than there has been in the past.
Unlike the pitch and roll axes, I am unaware of an aircraft that provides protections in the yaw axis. Should this be addressed by all manufacturers?
From Capt F...... "Should we all have been expressly warned of this? Well, my car handbook doesn't spell out for me what would happen if I decide to slam the shift into reverse at max speed, because they don't believe I would want to do that, and it has been the same for the aircraft builders. Of course in a country that tells you your coffee is hot, things may be different."
Lastly and unfortunately in the western world, act of god or 'accident' has disappeared from the dictionary. There must be blame - else no claim, unfortunately to human is to err.
Perhaps we should do as the journalists say and give up flying and travel by rail..........now there is a big can of worms.
Join Date: Jul 2002
Location: Cheshire
Posts: 51
Likes: 0
Received 0 Likes
on
0 Posts
Having had the privilege of flying some great aeroplanes - (C130, B757/767, A320/321/330) I also share the doubts regarding:
Rudder pedal travel
Rudder reversal
Rudder use during wake turbulence encounters
Can any '300' drivers confirm that there is really only one and a bit inches of rudder pedal travel?
As far back as basic training it was drummed into us that all flying controls are powerful creatures and should be treated with respect, (although on small aircraft full scale deflection was used regularly during aeros etc).
On larger aircraft (the Herc especially), large aggressive rudder movements are not encouraged - and I can't imagine a scenario where full scale deflection rudder would be aggressively required during normal flight on any large aircraft.
Even during an EFATO rudder input should be progressively applied quickly and smoothly - not aggressively.
X-wind landings only require a squeeze of rudder really, unless the conditions are very bad in which case it's a bit more - but again, never aggressively.
I have never found the need for large (if any) rudder applications during wake turbulence.
I suspect that AA's training regarding rudder during wake encounters maybe fault, and they do not wish to admit it, for obvious reasons of liability and litigation.
For them to bleat that they were never told that rapid rudder reversal is potentially dangerous is a bit disingenuous for me. They may never have been told - but isn't it obvious? Maybe not.
Did Boeing, McDonnell Douglas or Lockheed warn of this? I suspect not.
Also, not knowing the F/Os background or experience level, it may be that he found himself in a situation that he had not faced before and reacted as best he could, using the information available at the time, overcontrolling as he did so.
Unfortunately as always, it will probably end up with the major companies involved in a slanging match, with only the lawyers benefitting.
We'll all learn from this one I hope.
PS
(The conspiracy theory just ain't sound I'm afraid!)
PPS
Bootlegger - good question, may need a longish answer and I've gone on a long time already. There is a small bit about rudder ratios in 'Handling the Big Jets' page 263/4, and I'm sure other contributers will help out!
Rudder pedal travel
Rudder reversal
Rudder use during wake turbulence encounters
Can any '300' drivers confirm that there is really only one and a bit inches of rudder pedal travel?
As far back as basic training it was drummed into us that all flying controls are powerful creatures and should be treated with respect, (although on small aircraft full scale deflection was used regularly during aeros etc).
On larger aircraft (the Herc especially), large aggressive rudder movements are not encouraged - and I can't imagine a scenario where full scale deflection rudder would be aggressively required during normal flight on any large aircraft.
Even during an EFATO rudder input should be progressively applied quickly and smoothly - not aggressively.
X-wind landings only require a squeeze of rudder really, unless the conditions are very bad in which case it's a bit more - but again, never aggressively.
I have never found the need for large (if any) rudder applications during wake turbulence.
I suspect that AA's training regarding rudder during wake encounters maybe fault, and they do not wish to admit it, for obvious reasons of liability and litigation.
For them to bleat that they were never told that rapid rudder reversal is potentially dangerous is a bit disingenuous for me. They may never have been told - but isn't it obvious? Maybe not.
Did Boeing, McDonnell Douglas or Lockheed warn of this? I suspect not.
Also, not knowing the F/Os background or experience level, it may be that he found himself in a situation that he had not faced before and reacted as best he could, using the information available at the time, overcontrolling as he did so.
Unfortunately as always, it will probably end up with the major companies involved in a slanging match, with only the lawyers benefitting.
We'll all learn from this one I hope.
PS
(The conspiracy theory just ain't sound I'm afraid!)
PPS
Bootlegger - good question, may need a longish answer and I've gone on a long time already. There is a small bit about rudder ratios in 'Handling the Big Jets' page 263/4, and I'm sure other contributers will help out!
Join Date: Aug 1999
Location: Dublin, Ireland
Posts: 1,879
Likes: 0
Received 0 Likes
on
0 Posts
What concerned me after watching the program last night was that you had an airline which had been flying a type (in large numbers - 36 in service) for 12-13 years, which didn't seem to know certain vital facts.
They would have faced bad weather and they would have practiced drills in simulators; aren't the simulators Level 5 and therefore fully representative of the aircraft? It just seems strange that after what must be a good few thousand hours they can come along say, "what, 1 and a half inches . . . we never knew that?"
They would have faced bad weather and they would have practiced drills in simulators; aren't the simulators Level 5 and therefore fully representative of the aircraft? It just seems strange that after what must be a good few thousand hours they can come along say, "what, 1 and a half inches . . . we never knew that?"
Join Date: Mar 2001
Location: UK
Posts: 317
Likes: 0
Received 0 Likes
on
0 Posts
Would the same thing happen in a Boeing?
I too watched the Horizon documentary and was surprised to learn that full rudder deflection could cause loss of a tail. Designing a tail which is so vulnerable to catastrophic failure strikes me as a ludicrous weakness and one which ought to be addressed. I would like to think that any airliner I fly on is capable of handling full control surface deflections in case they are ever required to avert disaster. There are many cases of pilots who have flown outside the flight envelope in order to save the aircraft. I would be interested to know if such rudder inputs were applied to a Boeing with an aluminium tail whether it would fail also or whether it might be stronger.
Presumably sometime in the past 50 years other pilots may have done the same thing - the question is whether they survived because they were flying a conventionally constructed tailplance!
Desk-pilot
Presumably sometime in the past 50 years other pilots may have done the same thing - the question is whether they survived because they were flying a conventionally constructed tailplance!
Desk-pilot
Guest
Posts: n/a
..........was surprised to learn that full rudder deflection could cause loss of a tail.
Would you be surprised to learn that full elevator deflection could cause the loss of the wings ?
Would you be surprised to learn that full thrust lever deflection could cause the engines to explode/fail ?
Would you be surprised to learn that combined elevator and aileron above a certain design speed could cause structural failure ?
.....then be surprised !
Join Date: Jan 2001
Location: UK
Posts: 2,044
Likes: 0
Received 0 Likes
on
0 Posts
Desk-Pilot...
Your comments seems to illustrate you did not understand some of the points being made.
1. <<was surprised to learn that full rudder deflection could cause loss of a tail.>>
A single deflection at any stage cannot - the rudder limiting system keeps the load below a limit - ans the design strength is 1.5x that limit.
What can lost the fin is a full deflection held long enough to reach a stable yaw angle, and then the rudder reversed to full deflection the other way - and that did appear to happen (maybe more than once) here.
As was stated last night - it was felt initially the fin was to blame. However, further study showed the the reversal of rudder exceeded the "ultimate design strength", and hey presto, as advertised it failed. A Boeing Fin is designed to exactly the same certification requirements, and likely would also fail - hence the notices that went out after this from all manufacturers.
2. <<and one which ought to be addressed>>
Fine - we'll build all airliners out of 1" Stainless Steel. Trouble is it would cost 10x the ticket price - attractive idea now?
3. <<the question is whether they survived because they were flying a conventionally constructed tailplance!>>
Again - you missed the whole (eventual) point of the program. It was shown that the load exceeded the ultimate design strength as required for certification. Make your tailplane out of anything you want - if the load exceeds its ultimate strength it breaks (Boeings also do this funnily enough).
What they did not labour on, or make totally clear, was they method used for limiting rudder deflection on the A300-600. If one is going to use the rudder for anything other than the landing and takeoff phases, then the A300-600 system is, IMHO, "not ideal". This came back to the other point of the program was that Airbus' ideas and AA's ideas of rudders (if the training video was still AA policy) were very different...
NoD
Wino
<<As to AA;s training. They never advocated anything other than cooridinated rudder. There was a long discussion about crossover speed and high angle of attack and rudder inputs (VERY RELEVENT to loss of control crashes in the 737) but nobody was advocating stomping rudders.
The airplane is a trap for a Pilot induced oscilation in the yaw access at certain speeds.>>
I think you've hit the nail on the head. Given the strange rudder limiting system on the A300-600, use of measured / co-ordinated rudder at anything other than low speed is very hard to achieve, hence my comment that AA and Airbus' ideas were so different that an accident such as this was somewhat inevitable?
From Horizon last night, it seems a PIO was building up, if the AoB's shown were correct.... Very unusal for a wake encounter to repeatedly roll the aircraft from one side to another - my experiences are you generally get just rough air / a jolt, or if you get stuck in a vortex for a bit, a rolling moment (sometimes needing lots of aileron to stop the roll - no rush to get back level) in one direction.
Can all we just remember the purpose of accident investiagtion - it is not to allocate blame, but to prevent a repetition.
NoD
Your comments seems to illustrate you did not understand some of the points being made.
1. <<was surprised to learn that full rudder deflection could cause loss of a tail.>>
A single deflection at any stage cannot - the rudder limiting system keeps the load below a limit - ans the design strength is 1.5x that limit.
What can lost the fin is a full deflection held long enough to reach a stable yaw angle, and then the rudder reversed to full deflection the other way - and that did appear to happen (maybe more than once) here.
As was stated last night - it was felt initially the fin was to blame. However, further study showed the the reversal of rudder exceeded the "ultimate design strength", and hey presto, as advertised it failed. A Boeing Fin is designed to exactly the same certification requirements, and likely would also fail - hence the notices that went out after this from all manufacturers.
2. <<and one which ought to be addressed>>
Fine - we'll build all airliners out of 1" Stainless Steel. Trouble is it would cost 10x the ticket price - attractive idea now?
3. <<the question is whether they survived because they were flying a conventionally constructed tailplance!>>
Again - you missed the whole (eventual) point of the program. It was shown that the load exceeded the ultimate design strength as required for certification. Make your tailplane out of anything you want - if the load exceeds its ultimate strength it breaks (Boeings also do this funnily enough).
What they did not labour on, or make totally clear, was they method used for limiting rudder deflection on the A300-600. If one is going to use the rudder for anything other than the landing and takeoff phases, then the A300-600 system is, IMHO, "not ideal". This came back to the other point of the program was that Airbus' ideas and AA's ideas of rudders (if the training video was still AA policy) were very different...
NoD
Wino
<<As to AA;s training. They never advocated anything other than cooridinated rudder. There was a long discussion about crossover speed and high angle of attack and rudder inputs (VERY RELEVENT to loss of control crashes in the 737) but nobody was advocating stomping rudders.
The airplane is a trap for a Pilot induced oscilation in the yaw access at certain speeds.>>
I think you've hit the nail on the head. Given the strange rudder limiting system on the A300-600, use of measured / co-ordinated rudder at anything other than low speed is very hard to achieve, hence my comment that AA and Airbus' ideas were so different that an accident such as this was somewhat inevitable?
From Horizon last night, it seems a PIO was building up, if the AoB's shown were correct.... Very unusal for a wake encounter to repeatedly roll the aircraft from one side to another - my experiences are you generally get just rough air / a jolt, or if you get stuck in a vortex for a bit, a rolling moment (sometimes needing lots of aileron to stop the roll - no rush to get back level) in one direction.
Can all we just remember the purpose of accident investiagtion - it is not to allocate blame, but to prevent a repetition.
NoD
Nigel
Thank you for that post.
Alas, there are still many who will never accept the fundamental facts. Hopefully the pilots who fly these machines designed and certified to these standards will.
In this case I don't care who they want to blame (the courts ultimately decide this) just as long as the operators and crews learn from this accident.
Thank you for that post.
Alas, there are still many who will never accept the fundamental facts. Hopefully the pilots who fly these machines designed and certified to these standards will.
In this case I don't care who they want to blame (the courts ultimately decide this) just as long as the operators and crews learn from this accident.
Join Date: Aug 2000
Location: UK
Posts: 1,914
Likes: 0
Received 0 Likes
on
0 Posts
It seems the FEEL mechanism is not being considered here. Boeings have it and I can only assume Airbus too. Although at high speed the rudder pedal movement is restricted to a much smaller range than on the ground, the FEEL inputs to the rudder pedals would presumably make them feel very very heavy, therefore there is no dange of unintentionally pushing on large amounts of rudder. Certainly the 747 rudders at high speed feel solid and fixed, and never having had the desire to try out HOW much force is involved, I can't say exactly how solid, but the word 'rock' springs to mind!
The 747 device that varies Feel according to speed is the Rudder Ratio Changer: "This protects the vertical tail structure from stresses which could result from large rudder surface deflections at high airspeeds" (Tech Man). I would assume the Airbus has a similar feel system, however it would still have been at low airspeed allowing large deflections at a time of rapid upset. Maybe coupled with a pilot with a history of aggressive rudder inputs, a bad combination. I have seen several pilots myself with apparently over aggressive rudder techniques- presumably upbringing is an important factor. I remember after flying the VC10 I had to be trained out of this myself when converting to the Classic. From my early days in airline flying, i have always been made aware of 'take care with the rudder and use with great respect- it's the first of the flying controls that will fail on you'. Pilots know you can happily apply large aileron and elevator, but not to try it with the rudder.
The 747 device that varies Feel according to speed is the Rudder Ratio Changer: "This protects the vertical tail structure from stresses which could result from large rudder surface deflections at high airspeeds" (Tech Man). I would assume the Airbus has a similar feel system, however it would still have been at low airspeed allowing large deflections at a time of rapid upset. Maybe coupled with a pilot with a history of aggressive rudder inputs, a bad combination. I have seen several pilots myself with apparently over aggressive rudder techniques- presumably upbringing is an important factor. I remember after flying the VC10 I had to be trained out of this myself when converting to the Classic. From my early days in airline flying, i have always been made aware of 'take care with the rudder and use with great respect- it's the first of the flying controls that will fail on you'. Pilots know you can happily apply large aileron and elevator, but not to try it with the rudder.
Last edited by Notso Fantastic; 9th May 2003 at 20:51.
Join Date: Sep 2000
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
Ok, I'm not a pilot, so I ask humbly: is there any reason that Airbus shouldn't design the flight control software to make this accident impossible? Put it another way: is there a scenario where these agressive actions might prevent a different sort of accident? I am assuming that software can also allow a greater freedom during TO/Landing.
If not then surely this should be fixed to prevent an unlikely, but possible, repeat? Too much cost?
Not interested in blame, just being safe.
If not then surely this should be fixed to prevent an unlikely, but possible, repeat? Too much cost?
Not interested in blame, just being safe.
Join Date: Apr 2000
Location: Difficult Question
Posts: 47
Likes: 0
Received 0 Likes
on
0 Posts
Rudder Sensitivity
Previous posts state that the A300 rudder sensitivity and pedal load is increased deliberately with speed ( as well as the travel limit being reduced). However, the aileron sensitivity is effectively reduced with speed by 'locking' the outer ailerons.
Can anyone explain why this is so? I fly light aircraft and this seems counter-intuative to me.
Can anyone explain why this is so? I fly light aircraft and this seems counter-intuative to me.
Join Date: Aug 2000
Location: UK
Posts: 1,914
Likes: 0
Received 0 Likes
on
0 Posts
Rudder inputs at high speed produce very powerful effects, so the allowable range of movement is restricted AND the sensitivity is vastly increased. Full rudder at high speed would never be required.
Locking out the outboard ailerons is common- they are not needed at high speed- usually when flaps are up. Sensitivity would not be reduced by doing this. Thus they would still have increasing 'feel' with speed.
Any way you design flight control software to restrict one thing, somebody will find a way around it. So design must very carefully cater to what is being protected for- i don't think you can ever get it 'right'. Remember the A320 that flew into the trees restricting the pilot inputs because speed was too low to allow a pull up?
The Interflug upset into Moscow was horrifying- I didn't know about that one, and never knew an airliner could do that sort of aerobatics! But I distinctly remember a Tarom Airbus upset at Bucharest some 10-12 years ago- I know they lost one with an engine failure, but there was another upset that was similar to the Interflug- anyone remember?
Locking out the outboard ailerons is common- they are not needed at high speed- usually when flaps are up. Sensitivity would not be reduced by doing this. Thus they would still have increasing 'feel' with speed.
Any way you design flight control software to restrict one thing, somebody will find a way around it. So design must very carefully cater to what is being protected for- i don't think you can ever get it 'right'. Remember the A320 that flew into the trees restricting the pilot inputs because speed was too low to allow a pull up?
The Interflug upset into Moscow was horrifying- I didn't know about that one, and never knew an airliner could do that sort of aerobatics! But I distinctly remember a Tarom Airbus upset at Bucharest some 10-12 years ago- I know they lost one with an engine failure, but there was another upset that was similar to the Interflug- anyone remember?
Join Date: Jan 2001
Location: UK
Posts: 2,044
Likes: 0
Received 0 Likes
on
0 Posts
Saint...
I'm getting confused by what you mean by "sensitivity"??
Ailerons:
Most airliners have inboard and outboard, combine with spoilers on the downgoing wing. At high speed the outboard ailerons are "locked" out. However, I think someone posted here that the A300-600 does not have outboard ailerons??
Rudder:
Most aircraft allow a fixed amount of rudder deflection. As speed increases, full rudder deflection gives you less degrees of rudder deflection. However, the A300-600 just restricts the amount of rudder deflection. As Notso says, another important part of this is whether the "feel" i.e. force also changes with speed (this just simply replicates a Cessna 152 where the controls get harder to operate as speed increase due to airload).
BB
<<there any reason that Airbus shouldn't design the flight control software to make this accident impossible?>>
Well - they sort of have - its called an A320! In fact, I suspect the A320 is vulnerable to rudder reversal in the same way as here, but with most of the other Flight Envelope protections, "Upset" recoveries are not taught. You cannot overstress the aircraft in pitch, or stall it.... However, then you get all the Boeing Brigade jumping up and down about not liking "envelope protection" FBW!
NoD
Notso...
A310 Paris was Tarom I think? Some sort of impromptu aerobatic display near Orly - but all OK.
A310 in Bucharest. Something along lines of as power was reduced (to climb) one TL jammed. Machine kept "trying" to pull off power - resulted in Autopilot in with one at Full Power and one at idle - rolled in (Autopilot could not cope).
Moscow one - again I had not heard of that - looked pretty spectacular... but then so was the Icelandic B757 as Oslo recently (40deg nose down at 1500'? Recovered at 300'? And that was after the go-around!)
Best regards
NoD
I'm getting confused by what you mean by "sensitivity"??
Ailerons:
Most airliners have inboard and outboard, combine with spoilers on the downgoing wing. At high speed the outboard ailerons are "locked" out. However, I think someone posted here that the A300-600 does not have outboard ailerons??
Rudder:
Most aircraft allow a fixed amount of rudder deflection. As speed increases, full rudder deflection gives you less degrees of rudder deflection. However, the A300-600 just restricts the amount of rudder deflection. As Notso says, another important part of this is whether the "feel" i.e. force also changes with speed (this just simply replicates a Cessna 152 where the controls get harder to operate as speed increase due to airload).
BB
<<there any reason that Airbus shouldn't design the flight control software to make this accident impossible?>>
Well - they sort of have - its called an A320! In fact, I suspect the A320 is vulnerable to rudder reversal in the same way as here, but with most of the other Flight Envelope protections, "Upset" recoveries are not taught. You cannot overstress the aircraft in pitch, or stall it.... However, then you get all the Boeing Brigade jumping up and down about not liking "envelope protection" FBW!
NoD
Notso...
A310 Paris was Tarom I think? Some sort of impromptu aerobatic display near Orly - but all OK.
A310 in Bucharest. Something along lines of as power was reduced (to climb) one TL jammed. Machine kept "trying" to pull off power - resulted in Autopilot in with one at Full Power and one at idle - rolled in (Autopilot could not cope).
Moscow one - again I had not heard of that - looked pretty spectacular... but then so was the Icelandic B757 as Oslo recently (40deg nose down at 1500'? Recovered at 300'? And that was after the go-around!)
Best regards
NoD
Join Date: Aug 2000
Location: UK
Posts: 1,914
Likes: 0
Received 0 Likes
on
0 Posts
NOD, ah! 'Twas Paris. Can't remember the details of why, only that it was spectacular. Amazingly good piloting to recover from it, along with the Interflug, but what got into it?
Your 'Rudder' section above should read:"As speed increases, full rudder (Pedal) deflection gives you less degrees of rudder deflection" otherwise it won't make sense to people here trying to get their heads around this new concept!
To explain 'Feel', you are absolutely right: "this just simply replicates a Cessna 152 where the controls get harder to operate as speed increase due to airload". Jet airliners do not have any airload effects on flight control surfaces fed back to the control wheel/pedals as the flight control surfaces are fully hydraulically powered (exception B737 and DC9), therefore you need to have artificially generated 'feel' fed into the flight controls, and obviously this must be compensated for with increased speed and altitude which is what the 'Feel Units' are for.
Your 'Rudder' section above should read:"As speed increases, full rudder (Pedal) deflection gives you less degrees of rudder deflection" otherwise it won't make sense to people here trying to get their heads around this new concept!
To explain 'Feel', you are absolutely right: "this just simply replicates a Cessna 152 where the controls get harder to operate as speed increase due to airload". Jet airliners do not have any airload effects on flight control surfaces fed back to the control wheel/pedals as the flight control surfaces are fully hydraulically powered (exception B737 and DC9), therefore you need to have artificially generated 'feel' fed into the flight controls, and obviously this must be compensated for with increased speed and altitude which is what the 'Feel Units' are for.
Join Date: Apr 2002
Location: the edge of madness
Posts: 493
Likes: 0
Received 0 Likes
on
0 Posts
BobBuilder
As Nigel says, software might (or might not) help on a Fly By Wire (FBW) aircraft such as the A320 or B777, but the A300-600 is an "old fashioned" manual aircraft with the pilots more or less directly connected to the control surfaces via rods and wires - with a bit of help from hydraulics.
As Nigel says, software might (or might not) help on a Fly By Wire (FBW) aircraft such as the A320 or B777, but the A300-600 is an "old fashioned" manual aircraft with the pilots more or less directly connected to the control surfaces via rods and wires - with a bit of help from hydraulics.
In all my experience of swept wing jet transport aircraft I have never heard of anyone thrashing the rudders around to recover from an upset, including wake turbulence. The only time I might advocate rudder is if I have full aileron in to oppose roll and the aircraft is still departing.
When American Airlines decided to train their pilots this way, did they ask the aeroplane manufacturers (Airbus) first for their advice and opinion?
This almost sounds like a training induced accident. I would suggest that if these pilots had had no formal training in recovering from a wake turbulence encounter the outcome would have been very different.
When American Airlines decided to train their pilots this way, did they ask the aeroplane manufacturers (Airbus) first for their advice and opinion?
This almost sounds like a training induced accident. I would suggest that if these pilots had had no formal training in recovering from a wake turbulence encounter the outcome would have been very different.
Join Date: May 2003
Location: In a box
Posts: 137
Likes: 0
Received 0 Likes
on
0 Posts
I rather thought that from the picture of the control position indicator the rudder was well outside the indices for normal inputs, which I took to be the two red marks either side of the instrument display.
The Boeing 747 rudder ratio changer reduces rudder travel at about 186 kts I think, this makes it doubly strange that the programme said that you can get full rudder deflection from less rudder pedal input on the airbii, it seems counter intuitive....
The Boeing 747 rudder ratio changer reduces rudder travel at about 186 kts I think, this makes it doubly strange that the programme said that you can get full rudder deflection from less rudder pedal input on the airbii, it seems counter intuitive....
Union Goon
Join Date: Feb 2000
Location: New Jersey, USA
Posts: 1,097
Likes: 0
Received 0 Likes
on
0 Posts
Firefly,
As an American Airlines A300-605r pilot. I can tell you for certain that use of rudder was never advocated except as a last resort as the aircraft was getting away from you in a real serious upset. in other words, don't ignore the rudder if its all you have left. There were VERY long discussions of the effect of rudder, and what enourmous roll rate you could develope with it, especially at high angles of attack. How it related to crossover speed was really driven home. This was really aimed at the 737s community becuase of the rudder hard over problems.
No one EVER argued for a back and forth motion of the rudders, and on any other aircraft it never would have happened. But on the A300 some changes were made when they converted it to the 600 series that laid a trap.
NOD,
Outboard ailerons were deleted when the A300b4 became the A300600 series. Also, spoilers became "spoiler by wire" and most importantly the rudder load limiter was changed from a ratio changer system like the Boeings where 4 inches of travel always equalled full available rudder (be it 4 degrees at high speed or 40 degrees at low speed) to a fixed ratio changer where a jack screw simply restricts rudder PEDAL movement, rather than the movement of the rudder.
Notso,
Furthermore in a peculiarity of the system force required to reach the available stop decreases as the speed inceases untill it is virtually identical to breakout force. On the A300-605R there is NO rudder feel mechanism. The controll forces are NOT balanced and the stops get EASIER to reach as speed increases.
BTW, it gets alot smaller than 1 inch at barberpole. (it goes down to about .7 inches of travel at Vmo/Mmo
NOD again,
The bucharest crash was specifically cited in the AA maneuvering program. the Auto pilot was NOT engaged. The pilot flying the aircraft try to correct the asymetric engine condition with only ailerons, and not terribly aggressive movements of that. Airplane rolled over, all killed.
The Airbus single engine climb and crash on autopilot was the A330 during the test program that crashed killing all while trying to demonstrate a single engine go around on autopilot.
Cheers
Wino
As an American Airlines A300-605r pilot. I can tell you for certain that use of rudder was never advocated except as a last resort as the aircraft was getting away from you in a real serious upset. in other words, don't ignore the rudder if its all you have left. There were VERY long discussions of the effect of rudder, and what enourmous roll rate you could develope with it, especially at high angles of attack. How it related to crossover speed was really driven home. This was really aimed at the 737s community becuase of the rudder hard over problems.
No one EVER argued for a back and forth motion of the rudders, and on any other aircraft it never would have happened. But on the A300 some changes were made when they converted it to the 600 series that laid a trap.
NOD,
Outboard ailerons were deleted when the A300b4 became the A300600 series. Also, spoilers became "spoiler by wire" and most importantly the rudder load limiter was changed from a ratio changer system like the Boeings where 4 inches of travel always equalled full available rudder (be it 4 degrees at high speed or 40 degrees at low speed) to a fixed ratio changer where a jack screw simply restricts rudder PEDAL movement, rather than the movement of the rudder.
Notso,
Furthermore in a peculiarity of the system force required to reach the available stop decreases as the speed inceases untill it is virtually identical to breakout force. On the A300-605R there is NO rudder feel mechanism. The controll forces are NOT balanced and the stops get EASIER to reach as speed increases.
BTW, it gets alot smaller than 1 inch at barberpole. (it goes down to about .7 inches of travel at Vmo/Mmo
NOD again,
The bucharest crash was specifically cited in the AA maneuvering program. the Auto pilot was NOT engaged. The pilot flying the aircraft try to correct the asymetric engine condition with only ailerons, and not terribly aggressive movements of that. Airplane rolled over, all killed.
The Airbus single engine climb and crash on autopilot was the A330 during the test program that crashed killing all while trying to demonstrate a single engine go around on autopilot.
Cheers
Wino