NTSB Recommendation re Airbus Rudder Travel Limits
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Why is it every plane certificated has certified speeds that if not exceeded the pilot can penetrate severe turbulence and make abrupt control inputs...
And....
Vmo testing on jets requires Vmo +50kts then an abrupt pull-up to not show ANY structural damage....
Buy if you fly an Airbus...oh my gawd, you better not step on the rudder.....
And....
Vmo testing on jets requires Vmo +50kts then an abrupt pull-up to not show ANY structural damage....
Buy if you fly an Airbus...oh my gawd, you better not step on the rudder.....
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Here's a link to a NTSB powerpoint on the rudder/AAMP issue -
NTSB - AA587 Board Meeting - Operations
If people are really interesting in the accident I'd recommend viewing the NTSB site -
NTSB - American Airlines Flight 587
I'd recommend the statement by the lead investigator Robert Benzon(Hearing, day 1) as it has the animations, etc -
NTSB - Hearing Agenda
NTSB - AA587 Board Meeting - Operations
If people are really interesting in the accident I'd recommend viewing the NTSB site -
NTSB - American Airlines Flight 587
I'd recommend the statement by the lead investigator Robert Benzon(Hearing, day 1) as it has the animations, etc -
NTSB - Hearing Agenda
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so either there is one bad pilot (which I don't believe) or there is one bad plane (type).
I can't recall anyone else shaking a plane apart with rudder movements since WW2, can you? (and not the electra...that was whirl mode).
like the guy said...if you were in a plane and you were flying it and you pumped the rudder back and forth, you would ''feel it'' and know enough to stop.
someday this will happen again and the pilot won't be blamed.
I can't recall anyone else shaking a plane apart with rudder movements since WW2, can you? (and not the electra...that was whirl mode).
like the guy said...if you were in a plane and you were flying it and you pumped the rudder back and forth, you would ''feel it'' and know enough to stop.
someday this will happen again and the pilot won't be blamed.
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411A - The problem here is...'thought it meant'.
Versus...what the actual certification criteria are in CAR4B/14CFR25.
If we look back more than thirty years with jet transport training, the trainers then knew damn well what the problems were, and yet...the 'new breed' that came after, did not, and further, would reject any input from older/more experienced guys.
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There's only one problem saying the old guys knew it best. Some of us actually grew up with 'old guys' that started out before the jet age started. At least they had to courage, face to face, to admit they didn't know about the rudder issues either. It's the rare guy that said "I knew that". How rare? Except for you I havn't met him.
Who'd this left seat generation have as trainers? The current generation? Uh, no, the 'old guys'. I learned from the guys that started out in the 50's and 60's, ie the dawn of the jet era.(actually a few came from the WWII era). All an observer needs to know about how FOS you are is to actually hear some of the stories from the guys that actually did the transitions from props to jets. Your position "the old guys knew this stuff" looks like swiss cheese after talking with guys that actually started out in the pre jet era. (unfortunately we still have guys relearning some of the same issues when transistioning from straight wing, relatively low altitude and low winging loading, to swept wing, high speed, high altitude and high wing loading a/c).
You remind me of the retired guy talking about how their training as fighter pilots back in the 1960's was the best. Hahaha, he obviously didn't need the advances in training that came about during the following years. Red Flag? Top Gun? John Boyd? P sub S curves? E-M? Waste of money, they could have just asked him.... He had no clue what any of that stuff meant but he had the best training ever....
As far as 14CFR25? Oh puleeze. Anyone can read 14cfr25.147, 14cfr25.173, 14cfr25.175 and 14cfr25.177 and as a pilot it means nothing. Yeah, like the guys in the olden days knew what C.G. and force requirements the certification standards required.
Versus...what the actual certification criteria are in CAR4B/14CFR25.
If we look back more than thirty years with jet transport training, the trainers then knew damn well what the problems were, and yet...the 'new breed' that came after, did not, and further, would reject any input from older/more experienced guys.
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There's only one problem saying the old guys knew it best. Some of us actually grew up with 'old guys' that started out before the jet age started. At least they had to courage, face to face, to admit they didn't know about the rudder issues either. It's the rare guy that said "I knew that". How rare? Except for you I havn't met him.
Who'd this left seat generation have as trainers? The current generation? Uh, no, the 'old guys'. I learned from the guys that started out in the 50's and 60's, ie the dawn of the jet era.(actually a few came from the WWII era). All an observer needs to know about how FOS you are is to actually hear some of the stories from the guys that actually did the transitions from props to jets. Your position "the old guys knew this stuff" looks like swiss cheese after talking with guys that actually started out in the pre jet era. (unfortunately we still have guys relearning some of the same issues when transistioning from straight wing, relatively low altitude and low winging loading, to swept wing, high speed, high altitude and high wing loading a/c).
You remind me of the retired guy talking about how their training as fighter pilots back in the 1960's was the best. Hahaha, he obviously didn't need the advances in training that came about during the following years. Red Flag? Top Gun? John Boyd? P sub S curves? E-M? Waste of money, they could have just asked him.... He had no clue what any of that stuff meant but he had the best training ever....
As far as 14CFR25? Oh puleeze. Anyone can read 14cfr25.147, 14cfr25.173, 14cfr25.175 and 14cfr25.177 and as a pilot it means nothing. Yeah, like the guys in the olden days knew what C.G. and force requirements the certification standards required.
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411A - how does knowing the following section of 14CFR25 assist a pilot ?
Subpart B--Flight
Sec. 25.147 Directional and lateral control.
(a) Directional control; general. It must be possible, with the
wings level, to yaw into the operative engine and to safely make a
reasonably sudden change in heading of up to 15 degrees in the direction
of the critical inoperative engine. This must be shown at 1.4Vs1
for heading changes up to 15 degrees (except that the heading change at
which the rudder pedal force is 150 pounds need not be exceeded), and
with--
(1) The critical engine inoperative and its propeller in the minimum
drag position;
(2) The power required for level flight at 1.4 VS1, but
not more than maximum continuous power;
(3) The most unfavorable center of gravity;
(4) Landing gear retracted;
(5) Flaps in the approach position; and
(6) Maximum landing weight.
(b) Directional control; airplanes with four or more engines.
Airplanes with four or more engines must meet the requirements of
paragraph (a) of this section except that--
(1) The two critical engines must be inoperative with their
propellers (if applicable) in the minimum drag position;
(2) [Reserved]
(3) The flaps must be in the most favorable climb position.
(c) Lateral control; general. It must be possible to make 20 deg.
banked turns, with and against the inoperative engine, from steady
flight at a speed equal to 1.4 VS1, with--
(1) The critical engine inoperative and its propeller (if
applicable) in the minimum drag position;
(2) The remaining engines at maximum continuous power;
(3) The most unfavorable center of gravity;
(4) Landing gear (i) retracted and (ii) extended;
(5) Flaps in the most favorable climb position; and
(6) Maximum takeoff weight.
(d) Lateral control; airplanes with four or more engines. Airplanes
with four or more engines must be able to make 20 deg. banked turns,
with and against the inoperative engines, from steady flight at a speed
equal to 1.4 VS1, with maximum continuous power, and with the
airplane in the configuration prescribed by paragraph (b) of this
section.
(e) Lateral control; all engines operating. With the engines
operating, roll response must allow normal maneuvers (such as recovery
from upsets produced by gusts and the initiation of evasive maneuvers).
There must be enough excess lateral control in sideslips (up to sideslip
angles that might be required in normal operation), to allow a limited
amount of maneuvering and to correct for gusts. Lateral control must be
enough at any speed up to VFC/MFC to provide a
peak roll rate necessary for safety, without excessive control forces or
travel.
Subpart B--Flight
Sec. 25.147 Directional and lateral control.
(a) Directional control; general. It must be possible, with the
wings level, to yaw into the operative engine and to safely make a
reasonably sudden change in heading of up to 15 degrees in the direction
of the critical inoperative engine. This must be shown at 1.4Vs1
for heading changes up to 15 degrees (except that the heading change at
which the rudder pedal force is 150 pounds need not be exceeded), and
with--
(1) The critical engine inoperative and its propeller in the minimum
drag position;
(2) The power required for level flight at 1.4 VS1, but
not more than maximum continuous power;
(3) The most unfavorable center of gravity;
(4) Landing gear retracted;
(5) Flaps in the approach position; and
(6) Maximum landing weight.
(b) Directional control; airplanes with four or more engines.
Airplanes with four or more engines must meet the requirements of
paragraph (a) of this section except that--
(1) The two critical engines must be inoperative with their
propellers (if applicable) in the minimum drag position;
(2) [Reserved]
(3) The flaps must be in the most favorable climb position.
(c) Lateral control; general. It must be possible to make 20 deg.
banked turns, with and against the inoperative engine, from steady
flight at a speed equal to 1.4 VS1, with--
(1) The critical engine inoperative and its propeller (if
applicable) in the minimum drag position;
(2) The remaining engines at maximum continuous power;
(3) The most unfavorable center of gravity;
(4) Landing gear (i) retracted and (ii) extended;
(5) Flaps in the most favorable climb position; and
(6) Maximum takeoff weight.
(d) Lateral control; airplanes with four or more engines. Airplanes
with four or more engines must be able to make 20 deg. banked turns,
with and against the inoperative engines, from steady flight at a speed
equal to 1.4 VS1, with maximum continuous power, and with the
airplane in the configuration prescribed by paragraph (b) of this
section.
(e) Lateral control; all engines operating. With the engines
operating, roll response must allow normal maneuvers (such as recovery
from upsets produced by gusts and the initiation of evasive maneuvers).
There must be enough excess lateral control in sideslips (up to sideslip
angles that might be required in normal operation), to allow a limited
amount of maneuvering and to correct for gusts. Lateral control must be
enough at any speed up to VFC/MFC to provide a
peak roll rate necessary for safety, without excessive control forces or
travel.
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Except for you I havn't met him.
PanAmerican positively knew the score, as did Boeing...and that is where I received my initial jet transport training, circa 1974.
Missed it, did you?
Sorry, you are totally misinformed.
Certainly...not surprised.
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protectthehornet - the A320 incident shows that the response can trigger man/machine interface problems. 'Startle factor' becomes a dynamic that can lead to increasing control inputs. The a/c responds differently than the pilot expects and that problem is compounded when the pilot enters a PIO and the aircraft responds differently than expected.
It's easy enough to sit at your desk and say "I'd just stop doing that." These two incidents show the potential for man/machine interface problems is real. We've all been startled and responded differently then we would have hoped/expected. Now imagine this happens to you in the aircraft...as the NTSB lead investigator said "some events occur very rapidly, especially near the end of the animation".
The link to the NTSB powerpoint I provided states that the impact of rudder use at high airspeed isn't well known in the industry. Next time you're in the sim try doing fairly abrupt rudder movements at <160 kts, 210 kts, and 250 kts in the simulator. You don't have to be abrupt, just quick. In my experience the difference between 165 and 210 kts was about what I expected. 250 Kts was probably a bigger change than I expected, which is what the whole training was for.
Keep in mind the lateral loads you experience in the sim are less than those you'd experience in the a/c.
The downside might be 5 minutes wasted in the sim. The upside might be priceless.
It's easy enough to sit at your desk and say "I'd just stop doing that." These two incidents show the potential for man/machine interface problems is real. We've all been startled and responded differently then we would have hoped/expected. Now imagine this happens to you in the aircraft...as the NTSB lead investigator said "some events occur very rapidly, especially near the end of the animation".
The link to the NTSB powerpoint I provided states that the impact of rudder use at high airspeed isn't well known in the industry. Next time you're in the sim try doing fairly abrupt rudder movements at <160 kts, 210 kts, and 250 kts in the simulator. You don't have to be abrupt, just quick. In my experience the difference between 165 and 210 kts was about what I expected. 250 Kts was probably a bigger change than I expected, which is what the whole training was for.
Keep in mind the lateral loads you experience in the sim are less than those you'd experience in the a/c.
The downside might be 5 minutes wasted in the sim. The upside might be priceless.
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You haven't looked hard enough.
PanAmerican positively knew the score, as did Boeing...and that is where I received my initial jet transport training, circa 1974.
Missed it, did you?
Sorry, you are totally misinformed.
Certainly...not surprised
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OK, now we're getting somewhere. What exactly did the Pan Am pilot group know, and when did they know it?
As far as your initial jet training, was that Boeing or Pan Am back in 1974?
PanAmerican positively knew the score, as did Boeing...and that is where I received my initial jet transport training, circa 1974.
Missed it, did you?
Sorry, you are totally misinformed.
Certainly...not surprised
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OK, now we're getting somewhere. What exactly did the Pan Am pilot group know, and when did they know it?
As far as your initial jet training, was that Boeing or Pan Am back in 1974?
Last edited by misd-agin; 8th Aug 2010 at 20:29. Reason: added text
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Pan Am should have known it pretty well by 1974 as they had destroyed enough 707's by then. Nothing like learning the hard way to reinforce the message
OK, now we're getting somewhere. What exactly did the Pan Am pilot group know, and when did they know it?
As far as your initial jet training, was that Boeing or Pan Am back in 1974?
As far as your initial jet training, was that Boeing or Pan Am back in 1974?
One must then wonder...would 'new' jet transport pilots today, think anything about...moving the pole fore and aft, rapidly, to full travel...and expect the horizontal tail to stay attached...at 250 knots?
Why then, I would ask, would these same pilots expect anything different from the rudder/vertical stab?
Answers on a postcard.
John7022
perhaps this helps...http://www.pprune.org/5210206-post30.html
and here's the whole thread
http://www.pprune.org/professional-p...es-flight.html
Why is it every plane certificated has certified speeds that if not exceeded the pilot can penetrate severe turbulence and make abrupt control inputs...
and here's the whole thread
http://www.pprune.org/professional-p...es-flight.html
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411A - One must then wonder...would 'new' jet transport pilots today, think anything about...moving the pole fore and aft, rapidly, to full travel...and expect the horizontal tail to stay attached...at 250 knots?
Why then, I would ask, would these same pilots expect anything different from the rudder/vertical stab?
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Actually can you imagine the fear/shock/amazement if a transport pilot pulled on the yoke and the a/c responded completely differently than he expected?
Now add in the fact that it's moving even easier than expected. Imagine if that learning curve happened at the same instant and you had seconds to realize it while experiencing aircraft loads you didn't expect. Ugly scenario, isn't it?
You never answered what the Pan Am pilots knew, be it 1959 or 1974.
Why then, I would ask, would these same pilots expect anything different from the rudder/vertical stab?
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Actually can you imagine the fear/shock/amazement if a transport pilot pulled on the yoke and the a/c responded completely differently than he expected?
Now add in the fact that it's moving even easier than expected. Imagine if that learning curve happened at the same instant and you had seconds to realize it while experiencing aircraft loads you didn't expect. Ugly scenario, isn't it?
You never answered what the Pan Am pilots knew, be it 1959 or 1974.
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411, what's your point? Pan Am had a very poor safety record duirng the introduction of the 707 and right up until the mid 70's. Not all of the hull losses could be attributed to crew error or poor training but enough of them continued to happen that the FAA was taking an extremely hard look at the operation. Any other airline other than the mighty Pan Am would have been shut down. Not only did they have the hull losses they also had some serious training events that darn near caused the loss of the airplanes and crews.
I'm sure you recall the Boeing/Braniff accident up in Seattle. This was directly attributed to the Boeing instructor demonstrating the dutch roll characteristics of the new 707 to the initial cadre of Braniff pilots. It wasn't like Boeing did not know about this but the fact that the instructor intentionaly exceeded the parameters previously established for this maneuver.
Neither American, TWA or UAL suffered the line losses that PAA did although they did lose aircraft and flight crew duirng training accidents as I recall. I think AA has a pretty good operation even though I do not know a soul that currently fly's for them. All airlines have periods in their operational history which do not reflect well on them but your constant berating of AA is somewhat perplexing at times.
So you don't think I'm a total slacker I also received my initial type on the 707 at Pan Am in 1967 although my first Capt. trip in the airplane was not until 1971 at Western Airlines.
I'm sure you recall the Boeing/Braniff accident up in Seattle. This was directly attributed to the Boeing instructor demonstrating the dutch roll characteristics of the new 707 to the initial cadre of Braniff pilots. It wasn't like Boeing did not know about this but the fact that the instructor intentionaly exceeded the parameters previously established for this maneuver.
Neither American, TWA or UAL suffered the line losses that PAA did although they did lose aircraft and flight crew duirng training accidents as I recall. I think AA has a pretty good operation even though I do not know a soul that currently fly's for them. All airlines have periods in their operational history which do not reflect well on them but your constant berating of AA is somewhat perplexing at times.
So you don't think I'm a total slacker I also received my initial type on the 707 at Pan Am in 1967 although my first Capt. trip in the airplane was not until 1971 at Western Airlines.
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Startle factor, now we have something. PTH and I have probably never heard of startle factor. I assume that means something happens you were not expecting and over react. Jumping all over the rudders is not something I would do with startle factor. Maybe my adrenaline would go up but I wouldn't start beating up the airplane because of startle factor. I don't think the AA FO did either. I think the vertical stab separated from the aircraft from the front and the yaw caused a yaw that the gyroscopic forces spit the engines off and the vs finally separated totally. The FDR rudder data was not programmed for a vs coming loose. Notice the final left bank nose down death dive with full right rudder in the video? That was what the FDR recorded probably as the vs was separating. Airbus sold us a faulty airplane with a vs problem. Their attorneys managed to blame it on the FO so Airbus is out of the woods. It worked well for them.
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Just a question....
With regard to the USAir accident in Pittsburgh where the rudder hardover caused the crash....did not the rudder swing full one direction then the other (on its own due to a malfunction)? If so, why didn't the rudder shear off? Am I wrong, but didn't the rudder bang full displacement one way then the other....and still stay attached all the way to ground impact?
If the answer to the above is 'yes', at what speed did this occur?
Fly safe,
PantLoad
If the answer to the above is 'yes', at what speed did this occur?
Fly safe,
PantLoad
Thread Starter
PantLoad;
The DFDR on USAir 427 recorded only 14 parameters. Rudder position, yaw/yaw rate, pedal position, yaw-damper activity were not among those parameters recorded.
Recorded parameters were:
Time
Pressure Altitude
Airspeed
Mag Heading
Pitch
Roll
Vertical g
Longitudinal g
Captain's control column position
N1
N2
EGT
Fuel Flow
Microphone keying (either one)
PJ2
The DFDR on USAir 427 recorded only 14 parameters. Rudder position, yaw/yaw rate, pedal position, yaw-damper activity were not among those parameters recorded.
Recorded parameters were:
Time
Pressure Altitude
Airspeed
Mag Heading
Pitch
Roll
Vertical g
Longitudinal g
Captain's control column position
N1
N2
EGT
Fuel Flow
Microphone keying (either one)
PJ2
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P51 guy...I have never heard of "startle factor". cute term though. sure not in any books I've read!
talking about the rudder hardover at pittsburg (actually aliqupa). great tragedy. though they did hit wake turbulence and in that there is some similiarity to the american airbus accident.
I flew the 737...and didn't respect it as much the DC9 series. there was a nice handle on the DC9 that would depower the rudder with one easy move, leaving the rudder in manual reversion. turning off the rudder on the 737 is ahandful and leaves you with no manual reversion on the rudder.
and
Pan am may have had lots of crashes ...but they were pioneers...and pioneers teach the rest of us...sadly.
I want to say point blank that until the American accident, I believe that I could move the flight controls anyway I wanted and not cause the plane to fall apart (obeying and respecting placards and the limitations section).
So, we all learned a lesson...but there were better ways to teach it.
I for one, don't blame the copilot...I think the plane is one I wouldn't want to be on , in any capacity.
talking about the rudder hardover at pittsburg (actually aliqupa). great tragedy. though they did hit wake turbulence and in that there is some similiarity to the american airbus accident.
I flew the 737...and didn't respect it as much the DC9 series. there was a nice handle on the DC9 that would depower the rudder with one easy move, leaving the rudder in manual reversion. turning off the rudder on the 737 is ahandful and leaves you with no manual reversion on the rudder.
and
Pan am may have had lots of crashes ...but they were pioneers...and pioneers teach the rest of us...sadly.
I want to say point blank that until the American accident, I believe that I could move the flight controls anyway I wanted and not cause the plane to fall apart (obeying and respecting placards and the limitations section).
So, we all learned a lesson...but there were better ways to teach it.
I for one, don't blame the copilot...I think the plane is one I wouldn't want to be on , in any capacity.
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Pan Am was no more a 707 pioneer than TWA or AA. They were first on the order list but nothing more. The Pan Am accidents were more of an issue of airmanship than anything else. Sorry if that rubs the fur the wrong way.
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.did not the rudder swing full one direction then the other (on its own due to a malfunction)?
The action was a rudder hard-over, very similar in fact to the first rudder hard-over experienced with a jet transport airplane....an American Airlines 707 departing IDL (now JFK).
Pan Am had a very poor safety record duirng the introduction of the 707 and right up until the mid 70's. Not all of the hull losses could be attributed to crew error or poor training but enough of them continued to happen that the FAA was taking an extremely hard look at the operation.
However, AA purchased A300-600R aircraft, then introduced very poorly thought out upset training, using the powered rudder in a totally inapporopriate way...and had a hull loss, with many dead.
IE: it wasn't the airplane (as other airlines had the type, and still do), it was the totally inept upset training scenario that American Airlines developed...that did the deed.
No doubt about it.