CNN Reports FEDEX crash in Tokyo
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Interesting quote from avherald.com
"Emergency services needed two hours to extinguish the blaze. Although the fire brigades were able to keep the fire away from the cockpit, the crew could not be saved. The impact forces as well as the weight of debris in the cockpit had already killed the crew.
"
"Emergency services needed two hours to extinguish the blaze. Although the fire brigades were able to keep the fire away from the cockpit, the crew could not be saved. The impact forces as well as the weight of debris in the cockpit had already killed the crew.
"
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spleener:
MD-11 LSAS, Longitudinal Stability Augmentation System.
This is copied from the MD-11.org web study guide (great page, by the way)
LSAS provides:
1) Pitch Attitude Hold and Automatic Pitch Trim –With no force
on the control column, and bank angle less than 30 degrees,
LSAS holds the current pitch attitude. LSAS holds this attitude
by deflecting the elevators as much as 5 degrees. The
horizontal stabilizer is automatically adjusted to relieve the
sustained elevator deflection and maintain a full 5 degree
elevator authority.
2) Pitch Attitude Limiting –LSAS maintains pitch attitude to less
than 10 degrees of dive, or less than 30 degrees of climb.
3) Pitch Rate Damping – Increases the apparent static stability to
reduce the chance of over-control in pitch. It is active
throughout the flight envelope. 100% of max damping is
available above 20,000ft, decreasing linearly to 30% below
16,500 ft.
4) Speed Protection – If the autopilot is not engaged and the
autothrottle is not available (or able to maintain a safe speed),
LSAS Speed Limiting will engage to provide overspeed or
stall protection. LSAS overspeed protection is accomplished
by changing pitch. LSAS does not provide flap, slat or gear
overspeed protection.
5) Stall Protection – At 75-85 pct of the angle of attack required
to activate the stick shaker, the LSAS stall protection engages.
LSAS reduces pitch until the AOA is sufficiently reduced.
6) Pitch Attitude Protection and Positive Nose Lowering -During
takeoff rotation, LSAS provides Pitch Attitude Protection
(PAP) to reduce the possibility of a tail strike. During landing,
after spoiler deployment is commanded, LSAS initiates
Positive Nose Lowering (PNL) to assist in transitioning the
nose wheel to the runway after main gear touchdown.
I have read a lot of nonsense in pprune. But that has to take the cake 
MD-11 LSAS, Longitudinal Stability Augmentation System.
This is copied from the MD-11.org web study guide (great page, by the way)
LSAS provides:
1) Pitch Attitude Hold and Automatic Pitch Trim –With no force
on the control column, and bank angle less than 30 degrees,
LSAS holds the current pitch attitude. LSAS holds this attitude
by deflecting the elevators as much as 5 degrees. The
horizontal stabilizer is automatically adjusted to relieve the
sustained elevator deflection and maintain a full 5 degree
elevator authority.
2) Pitch Attitude Limiting –LSAS maintains pitch attitude to less
than 10 degrees of dive, or less than 30 degrees of climb.
3) Pitch Rate Damping – Increases the apparent static stability to
reduce the chance of over-control in pitch. It is active
throughout the flight envelope. 100% of max damping is
available above 20,000ft, decreasing linearly to 30% below
16,500 ft.
4) Speed Protection – If the autopilot is not engaged and the
autothrottle is not available (or able to maintain a safe speed),
LSAS Speed Limiting will engage to provide overspeed or
stall protection. LSAS overspeed protection is accomplished
by changing pitch. LSAS does not provide flap, slat or gear
overspeed protection.
5) Stall Protection – At 75-85 pct of the angle of attack required
to activate the stick shaker, the LSAS stall protection engages.
LSAS reduces pitch until the AOA is sufficiently reduced.
6) Pitch Attitude Protection and Positive Nose Lowering -During
takeoff rotation, LSAS provides Pitch Attitude Protection
(PAP) to reduce the possibility of a tail strike. During landing,
after spoiler deployment is commanded, LSAS initiates
Positive Nose Lowering (PNL) to assist in transitioning the
nose wheel to the runway after main gear touchdown.
The picture referenced by ManAdaSystem in post 19 showing a KLM MD11 on final approach and the tailplane angle indicates a real problem. I have seen MD11s with this absurd tailplane incidence many times. Does it not show a fundamental misdesign? The wing is evidently too far back- it even looks it. The tailplane is desperately trying to provide enough downforce. Put yourself in a baulked landing with low airspeed and you then have a real problem trying to hold the nose up. If the pilots had full back elevator and the nose still fell like that, then this aeroplane should be withdrawn from service.
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My addled grey cells seem to recall that a while back there was a bit of a fuss because the FAA wanted to merge DC10 and MD11 licences - despite the aircraft having distinctly different handling characteristics..
For my pennyworth the MD11 never 'looked' right...appearing in take off configuration almost as if it were in landing mode, an awful lot of flap out..
I remember the first time I saw one when working for AA. It looked mishapen, parts put together rather than a complete design.
If it don't look right - then it don't fly right!
For my pennyworth the MD11 never 'looked' right...appearing in take off configuration almost as if it were in landing mode, an awful lot of flap out..
I remember the first time I saw one when working for AA. It looked mishapen, parts put together rather than a complete design.
If it don't look right - then it don't fly right!
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One would think the simple imbalance of wing on one side, no wing on the other side would be enough to roll the aircraft inverted. The MD11 seems to have a disturbing tendency towards wing failure at the root following a hard impact. Maybe it's a weakness of the wing root plug design from when they stretched the DC10 wing, maybe not, but it's not often you see another type of aircraft with it's wing cleanly detached at the root.
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Not to judge, just to say what I see/ saw: Looks like oscillating bounces followed by a gear collapse an/ or loss of control causing the aircraft to hit the ground with its left wing and roll. Amazing though that it pretty much slided on its back and did not roll further. Notice the nose, right main and centre gear pretty much still there on the pictures.
As a former FedEx employee, my condoleances to the relatives and friends of the pilots.
Ptt,
As a former FedEx employee, my condoleances to the relatives and friends of the pilots.
Ptt,
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And that makes 4...3 fedex and one china/air china?? same scenario..hard landing wing root failure, over she goes...something wrong here??
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The Toxic One will have a go at me I'm sure but....
It seems to me that it all happened during the initial touchdown. Looking at all the clips that are available the aircraft (a) appears to be moving very fast for a final approach (b) the touchdown was very firm (given the amount of tyre smoke that can be seen) and (c) the nose comes down very quickly. You expect to see the nose being kept high for several seconds to allow the lift to decay after the mains have made firm contact. Not so here.
I can't tell whether the spoilers deployed or not. If the trigger to automatically deploy them is firm weight on the nosewheel then it looks as if that was never achieved because the nose came back up again very rapidly and may not have touched the ground at all.
Can it be that we looking at a "computer commands one thing - Pilot Flying tries to do the right thing but is over-ridden" scenario here?
It seems to me that it all happened during the initial touchdown. Looking at all the clips that are available the aircraft (a) appears to be moving very fast for a final approach (b) the touchdown was very firm (given the amount of tyre smoke that can be seen) and (c) the nose comes down very quickly. You expect to see the nose being kept high for several seconds to allow the lift to decay after the mains have made firm contact. Not so here.
I can't tell whether the spoilers deployed or not. If the trigger to automatically deploy them is firm weight on the nosewheel then it looks as if that was never achieved because the nose came back up again very rapidly and may not have touched the ground at all.
Can it be that we looking at a "computer commands one thing - Pilot Flying tries to do the right thing but is over-ridden" scenario here?
Last edited by Xeque; 23rd Mar 2009 at 14:42.
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Having worked for FedEx for 13+ yrs, I am still close to many crew and staff. It's painful to see the unfolding events as I know FedEx crews are well trained and the company takes its role as an airline seriously.
My sympathies to the family, friends and staff at FedEx.
My sympathies to the family, friends and staff at FedEx.
Thanks Burger T. makes more sense than in humpys at dark o'clock.
May not be relevent in this case [let's see the official report], but does the LSAS inhibit stall protection at low altitude - eg 'bus below 100'ra?
Also the statement:
"During landing, after spoiler deployment is commanded, LSAS initiates
Positive Nose Lowering (PNL) to assist in transitioning the
nose wheel to the runway after main gear touchdown."
...is a bit chilling after seeing the video - and I guess explains the requirement for bounced landing training on this type.
Ironbutts57 - sorry I had the count wrong?
May not be relevent in this case [let's see the official report], but does the LSAS inhibit stall protection at low altitude - eg 'bus below 100'ra?
Also the statement:
"During landing, after spoiler deployment is commanded, LSAS initiates
Positive Nose Lowering (PNL) to assist in transitioning the
nose wheel to the runway after main gear touchdown."
...is a bit chilling after seeing the video - and I guess explains the requirement for bounced landing training on this type.
Ironbutts57 - sorry I had the count wrong?
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L-1011
Sorry to digress but, in response to earlier posts, yes the TriStar was a different animal. CX drivers may remember the "Hump" at the end of the runway at the old Payar Lebar airport in SIN and how she would just sit there over the hump on landing, in any conditions. Memories. Sorry, back to topic!
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Originally Posted by ManaAdaSystem
Just to illustrate the typical stabilizer angle during approach.
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From the MD11 FCOM (Systems):
Pitch Attitude Protection (PAP) reduces the chance of a tail strike during take-off and landing by adding nose down elevator if the aircraft is at serious risk of tail contact with the ground. PAP is a direct function of pitch attitude, radio altitude and pitch rate and is enabled below 100 feet RA. The pitch attitude limit will vary linearly from 30 deg at 40 feet RA to 9.5 deg at 0 feet RA.
Positive Nose Lowering (PNL) will apply 3 deg of nose-down elevator command when the FCC commands the Auto Ground Spoilers to extend at main wheel spinup. As the spoilers extend beyond 10 deg, PNL will increase the nose-down elevator command to 4 deg. The command fades out when FD mode cycles back to T/O, or if throttles are advanced for G/A.
During take-off and landing flight phases, when PAP or PNL is active, approximately 10-15 pounds of force on the control column is required to override LSAS.
Xeque: The ground spoilers are automatically retracted when #2 throttle is advanced, or they can be manually retracted if already extended. Also, with MLG spin-up, the ground spoilers will only deploy approximately 60% until NLG wheel spinup, when the ground spoilers will deploy to 100%.
LSAS stall protection: I cannot find a reference, either in the FCOM or AMM to a RA input/flight condition where LSAS stall protection is not available.
However, again from the MD11 FCOM:
...the pilot may counteract the LSAS overspeed or stall protection by pushing on the control column with enough force to defeat the LSAS elevator inputs. This force is approximately 50 pounds. If the pilot releases the control column force rapidly, LSAS will dampen the resulting elevator instability.
(my highlighting)
Pitch Attitude Protection (PAP) reduces the chance of a tail strike during take-off and landing by adding nose down elevator if the aircraft is at serious risk of tail contact with the ground. PAP is a direct function of pitch attitude, radio altitude and pitch rate and is enabled below 100 feet RA. The pitch attitude limit will vary linearly from 30 deg at 40 feet RA to 9.5 deg at 0 feet RA.
Positive Nose Lowering (PNL) will apply 3 deg of nose-down elevator command when the FCC commands the Auto Ground Spoilers to extend at main wheel spinup. As the spoilers extend beyond 10 deg, PNL will increase the nose-down elevator command to 4 deg. The command fades out when FD mode cycles back to T/O, or if throttles are advanced for G/A.
During take-off and landing flight phases, when PAP or PNL is active, approximately 10-15 pounds of force on the control column is required to override LSAS.
Xeque: The ground spoilers are automatically retracted when #2 throttle is advanced, or they can be manually retracted if already extended. Also, with MLG spin-up, the ground spoilers will only deploy approximately 60% until NLG wheel spinup, when the ground spoilers will deploy to 100%.
LSAS stall protection: I cannot find a reference, either in the FCOM or AMM to a RA input/flight condition where LSAS stall protection is not available.
However, again from the MD11 FCOM:
...the pilot may counteract the LSAS overspeed or stall protection by pushing on the control column with enough force to defeat the LSAS elevator inputs. This force is approximately 50 pounds. If the pilot releases the control column force rapidly, LSAS will dampen the resulting elevator instability.
(my highlighting)
Really ? To the extent of building up the world's largest fleet of a type which is proven continually prone to this type of incident ? Who continue to enlarge their fleet with secondhand units of this type despite disaster after disaster ?
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Is not the first MD11 that does not remain side up...is this aircraft prone to end up upside down more than other models?
Here's an article posted by Huck (I think he still flies MD's for FedEx) a while back about MD landing issues:
http://www.pprune.org/rumours-news/2...ml#post2764418
It it tragic that FedEx's string of hull losses continues, this time with fatal results.
As I commented here after one of the earlier FedEx MD landing mishaps:
>>by now FED EX must have one of the worst hull loss records in the industry!
My addled grey cells seem to recall that a while back there was a bit of a fuss because the FAA wanted to merge DC10 and MD11 licences - despite the aircraft having distinctly different handling characteristics..
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The cause of the rollovers is simple: One wing breaks away at the wing root.
During the accident investigations of the '97 (FedEx) and '99 (Air China) rollovers the NTSB looked very closely into the forces and strength of MLG and main wing spar. Using DFDR data they where able to calculate that the forces where beyond design loads and safety margins. - Therefore the wing "was allowed" to break regarding the construction standards.
On the other hand other aircraft are much more stable: The 346 in Quito (overrun in 2007) "touched" down with > 3G and sustained no structural damage (apart from the Boogeys and wheels) until it overran.
When BA038 crashed in LHR last year the MLG was pushed through the wing but the wing structure itself did not fail.
Marcus
During the accident investigations of the '97 (FedEx) and '99 (Air China) rollovers the NTSB looked very closely into the forces and strength of MLG and main wing spar. Using DFDR data they where able to calculate that the forces where beyond design loads and safety margins. - Therefore the wing "was allowed" to break regarding the construction standards.
On the other hand other aircraft are much more stable: The 346 in Quito (overrun in 2007) "touched" down with > 3G and sustained no structural damage (apart from the Boogeys and wheels) until it overran.
When BA038 crashed in LHR last year the MLG was pushed through the wing but the wing structure itself did not fail.
Marcus
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Observing the video link posted by Carnage Matey, I seems that the plane touched down in a "normal" attitude - how hard I can't judge - but what I see next is:
-the MLG bouncing up a few feet before the NLG even touches the rwy;
-NLG hits the ground with MLG still up pushing it down again;
-After this second MLG touch down, the apparent porpoising effect seems almost controlled, with the plane in a G/A like attitude, but the speed drops in the middle of this second bounce.
-Plane hits the rwy NLG first this time, the A/C bounces again, sits and slides on its tail, wheels off the ground. Without LH or RH wheel lateral support it can tilt either way, gusts, cargo shifting do the rest, flipping it upside-down.
-the MLG bouncing up a few feet before the NLG even touches the rwy;
-NLG hits the ground with MLG still up pushing it down again;
-After this second MLG touch down, the apparent porpoising effect seems almost controlled, with the plane in a G/A like attitude, but the speed drops in the middle of this second bounce.
-Plane hits the rwy NLG first this time, the A/C bounces again, sits and slides on its tail, wheels off the ground. Without LH or RH wheel lateral support it can tilt either way, gusts, cargo shifting do the rest, flipping it upside-down.