CNN Reports FEDEX crash in Tokyo
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Touch 'n' oops,
The nosewheels didn't shear off. Both of the hubs are clearly still there on the axle. The tyres probably perished from the heat of the flames.
The nosewheels didn't shear off. Both of the hubs are clearly still there on the axle. The tyres probably perished from the heat of the flames.
Last edited by Flightmech; 23rd Mar 2009 at 22:07.
Take your point re: the image - but the burnt wing remains are a couple of degrees forward of where they should be (straight leading edge)(camera angles/zooms etc taken as very variable). Which 'just might' be the case if the flailing sub-structures directed it to. Or, of course, maybe I'm wrong, and the position of the remains of the wing is due to all of the almost incalculable stresses it sustained.
However, if you watch the video as often as I have, you might understand why I have convinced myself that the outer wing panel rotates (in roll) faster than the fuselage and stbd engine?
However, if you watch the video as often as I have, you might understand why I have convinced myself that the outer wing panel rotates (in roll) faster than the fuselage and stbd engine?
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Right
I was extrapolating. The wing snapped loose, but remained attached. I refer to the post (#65). I had assumed it parted, evidently not. Thx.
AF
Check the wing's remains, they look as if they've rotated front to back. the tip angle, flap structure, etc. "twisted" around the main spar.
AF
Check the wing's remains, they look as if they've rotated front to back. the tip angle, flap structure, etc. "twisted" around the main spar.
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I suspect some of the posters who talk of the "right wing" being separated are stunningly unaware that the airplane is upside down. Ready, fire, aim...
Stephan Wilkinson
Stephan Wilkinson
Just a thought, if the initial NLG touchdown was sufficiently forceful, is it possible that any remaining control of the aircraft was lost at this point, pilots unable to respond to anything after initial touchdown rather than an attempted correction gone awry?
Agreed. In that image, the Port wing is separated. The remains of the severely burnt Starboard wing are just dust towards the bottom of the picture. However, the pattern is about two or three degrees forward of where it should be. I'll say again. The camera angle makes it look that way, but who knows?
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FYI: From The Aviation Herald :-
The JTSB reported, that the flight data recorder and cockpit voice recorder have both been recovered, data analysis has started. The nose gear tires were found separated from the wheels supposedly departing the rims when the airplane touched down the second time with the nose gear first, the left wing broke off at the wing root at impact with the runway. The NTSB (USA) is joining the investigation with a go-team.
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Flightmech:
I know what you thought and so did I, but see the post before this one. Those are not the rims. Compare with this photo http://farm1.static.flickr.com/168/4...2972b1.jpg?v=0
I know what you thought and so did I, but see the post before this one. Those are not the rims. Compare with this photo http://farm1.static.flickr.com/168/4...2972b1.jpg?v=0
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Absolutely
The Md-11 and Dc-10 have bogies and a Center gear that are aft of the CG. Assuming, windshear advisory they were flying into a slight angled crosswind at 40kt they were 10 kt above calculated speed, windshear, overrotation and roll input to compensate driving the mlg and cg harder into the ground.
Followed by
Loss of A/S, possible elevator input from a late reaction fatally driving the nose into the ground and a 2nd bounce off the mains, lost enough a/s to come down with the left wing stalled out (cross wind/ or W/S adding to the situation).
I have experienced similar sucessfull landings in a DC-10-30 and a MD-11.
Dc-10-30 F/O landing, below G/S. Attempts to compensate with a too late flare, heard 30 on the R.A callout the 2nd time around bouncing and landing hard in a 1 wing stall.
Md-11, Windshear at 30 R.A., full aileron input to compensate no help, hard landing on one gear, allmost scraped the eng.
Followed by
Loss of A/S, possible elevator input from a late reaction fatally driving the nose into the ground and a 2nd bounce off the mains, lost enough a/s to come down with the left wing stalled out (cross wind/ or W/S adding to the situation).
I have experienced similar sucessfull landings in a DC-10-30 and a MD-11.
Dc-10-30 F/O landing, below G/S. Attempts to compensate with a too late flare, heard 30 on the R.A callout the 2nd time around bouncing and landing hard in a 1 wing stall.
Md-11, Windshear at 30 R.A., full aileron input to compensate no help, hard landing on one gear, allmost scraped the eng.
Just call me Rotty
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The news this morning shows a large collection of machinery cleaning up the wreckage, evidently they are hoping to open the runway later today.
Dozens of flights are still being affected; many pax have been bussed to other airports.
Kudos to the Narita Airport Authority, despite this being their first incident it seems they are coping very well with both the crash and its aftermath.
Dozens of flights are still being affected; many pax have been bussed to other airports.
Kudos to the Narita Airport Authority, despite this being their first incident it seems they are coping very well with both the crash and its aftermath.
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"Am I right in thinking that the MD11 has a couple of features to assist in the lowering of the nose-wheel upon touch down?
-Ground spoilers deploy only initially to 45deg until the nose-wheel strut is compressed, then the spoiler handle continues to the 60deg (full position).
-Engine 2 is limited to idle reverse until the nose-wheel strut is compressed.
Is this correct?"
The FCC's recieved a program correction years ago to drive the stab A.N.D. after the MLG is compressed to my knowledge years ago as a result of several tail strikes. The Md-11 is not an aircraft that is safe to perform "aerodynamic breaking" in because of the smaller horizontal stab.
This could have had a slight influence.
-Ground spoilers deploy only initially to 45deg until the nose-wheel strut is compressed, then the spoiler handle continues to the 60deg (full position).
-Engine 2 is limited to idle reverse until the nose-wheel strut is compressed.
Is this correct?"
The FCC's recieved a program correction years ago to drive the stab A.N.D. after the MLG is compressed to my knowledge years ago as a result of several tail strikes. The Md-11 is not an aircraft that is safe to perform "aerodynamic breaking" in because of the smaller horizontal stab.
This could have had a slight influence.
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FCOM
Without wanting to judge, just to provide additional information: Boeing MD-11 FCOM vol 2 procedures and techniques PT30.2:
Also from FCOM3:
Bounced Landing Recovery
If the aircraft should bounce, hold or re-establish a normal landing attitude
and add thrust as necessary to control the rate of descent. Avoid rapid
pitch rates in establishing a normal landing attitude.
CAUTION: Tail strikes or nosewheel structural damage can
occur if large forward or aft control column movements
are made prior to touchdown.
When a bounced landing occurs, consider initiating a go-around by use of
normal go-around procedures. Do not retract the landing gear until a
positive rate of climb is established because a second touchdown may
occur during the go-around.
I've been flying the MD-11 for more than 10 years and must say the FCC update has made the aircraft more stable. Luckily I've never found myself having to recover from such a bounced landing as seen in the video. Certainly, the MD-11 may not have the greatest elevator authority. But I expect it may be able to hold a landing attitude as well as other large transport category aircraft. I'm wondering however how g forces during the bounce will affect the pilots ability to "hold it steady" though. Hopefully we will all be able to learn from data from the FDR. If the aircraft should bounce, hold or re-establish a normal landing attitude
and add thrust as necessary to control the rate of descent. Avoid rapid
pitch rates in establishing a normal landing attitude.
CAUTION: Tail strikes or nosewheel structural damage can
occur if large forward or aft control column movements
are made prior to touchdown.
When a bounced landing occurs, consider initiating a go-around by use of
normal go-around procedures. Do not retract the landing gear until a
positive rate of climb is established because a second touchdown may
occur during the go-around.
Also from FCOM3:
Longitudinal Stability Augmentation System (LSAS)
The Longitudinal Stability Augmentation System (LSAS) enhances longitudinal
stability and provides:
• Pitch attitude hold.
• Pitch attitude limiting.
• Pitch rate damping.
• Pitch attitude protection.
• Positive nose lowering.
• Speed limiting.
• Stall protection.
Each FCC contains two LSAS control channels. This provides four redundant
channels of control. LSAS operates through series control of the elevators (no
movement of control column), and is inhibited when autopilot is engaged.
With less than 2 pounds of force applied on the control column, LSAS holds pitch
attitude by deflecting the elevators up to +/-5°. LSAS provides automatic
horizontal stabilizer trim to off load steady-state elevator displacement, restoring
a full 5° of elevator authority. Whenever there is more than 2 pounds of force on
the control column, pitch attitude hold function is inhibited and the aircraft rotates
in proportion to the applied force. When force is then removed from the column,
the aircraft holds the new pitch attitude. Pitch attitude hold is inhibited at bank
angles exceeding 30° or below 100 feet RA.
Pitch Attitude Limiting (PAL) ensures that LSAS will only hold a pitch attitude
between 30° ANU and 10° AND.
Pitch Rate Damping (PRD) increases the apparent static stability to reduce the
chance of overcontrol in pitch, especially at high altitudes. It is active throughout
the flight envelope, below 16,500 feet at 30% of the maximum damping
(FCC-908) increasing linearly to 100% above 20,000 feet.
Pitch Attitude Protection (PAP)(FCC-908) 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° at 40 feet RA to 9.5° at 0 feet RA.
Positive Nose Lowering (PNL)(FCC-908) will apply 3° 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°, PNL will increase the
nose-down elevator command to 4°. 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.
Upon detecting a fault, both channels of one FCC shut down. After selecting both
failed channels off, the remaining FCC is armed to revert to single LSAS channel
operation should one of the two remaining LSAS channels fail. The remaining
LSAS channels will increase deflection 2-fold (4-fold deflection occurs
automatically in case of reversion to single elevator LSAS operation).
Question is, what caused the nose lowering: pilot input or LSAS. In both cases things need to be changed.
The Longitudinal Stability Augmentation System (LSAS) enhances longitudinal
stability and provides:
• Pitch attitude hold.
• Pitch attitude limiting.
• Pitch rate damping.
• Pitch attitude protection.
• Positive nose lowering.
• Speed limiting.
• Stall protection.
Each FCC contains two LSAS control channels. This provides four redundant
channels of control. LSAS operates through series control of the elevators (no
movement of control column), and is inhibited when autopilot is engaged.
With less than 2 pounds of force applied on the control column, LSAS holds pitch
attitude by deflecting the elevators up to +/-5°. LSAS provides automatic
horizontal stabilizer trim to off load steady-state elevator displacement, restoring
a full 5° of elevator authority. Whenever there is more than 2 pounds of force on
the control column, pitch attitude hold function is inhibited and the aircraft rotates
in proportion to the applied force. When force is then removed from the column,
the aircraft holds the new pitch attitude. Pitch attitude hold is inhibited at bank
angles exceeding 30° or below 100 feet RA.
Pitch Attitude Limiting (PAL) ensures that LSAS will only hold a pitch attitude
between 30° ANU and 10° AND.
Pitch Rate Damping (PRD) increases the apparent static stability to reduce the
chance of overcontrol in pitch, especially at high altitudes. It is active throughout
the flight envelope, below 16,500 feet at 30% of the maximum damping
(FCC-908) increasing linearly to 100% above 20,000 feet.
Pitch Attitude Protection (PAP)(FCC-908) 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° at 40 feet RA to 9.5° at 0 feet RA.
Positive Nose Lowering (PNL)(FCC-908) will apply 3° 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°, PNL will increase the
nose-down elevator command to 4°. 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.
Upon detecting a fault, both channels of one FCC shut down. After selecting both
failed channels off, the remaining FCC is armed to revert to single LSAS channel
operation should one of the two remaining LSAS channels fail. The remaining
LSAS channels will increase deflection 2-fold (4-fold deflection occurs
automatically in case of reversion to single elevator LSAS operation).
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It will be interesting to see what the FDR makes of the speed over the fence. It looks fast and has the hallmark of mainwheels first, nose down to complete the landing by which time the mainwheels are off the ground again. The rest of the oscillation is down to science but there is a definite 'puff' when the nosewheels hit the second time, probably losing tyres and rims.
Fast over the fence could be for a number of reasons in those wind conditions.
Fast over the fence could be for a number of reasons in those wind conditions.
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Burbank
I'd even go so far as too select out that whole section on PAP and and PNL for a good read - and feature the last paragraph.
I'd even go so far as too select out that whole section on PAP and and PNL for a good read - and feature the last paragraph.
Pitch Attitude Protection (PAP)(FCC-908) 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° at 40 feet RA to 9.5° at 0 feet RA.
Positive Nose Lowering (PNL)(FCC-908) will apply 3° 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°, PNL will increase the
nose-down elevator command to 4°. 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.
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° at 40 feet RA to 9.5° at 0 feet RA.
Positive Nose Lowering (PNL)(FCC-908) will apply 3° 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°, PNL will increase the
nose-down elevator command to 4°. 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.
Bounced Landing Recovery
If the aircraft should bounce, hold or re-establish a normal landing attitude
and add thrust as necessary to control the rate of descent. Avoid rapid
pitch rates in establishing a normal landing attitude.
CAUTION: Tail strikes or nosewheel structural damage can
occur if large forward or aft control column movements
are made prior to touchdown.
When a bounced landing occurs, consider initiating a go-around by use of
normal go-around procedures. Do not retract the landing gear until a
positive rate of climb is established because a second touchdown may
occur during the go-around.
If the aircraft should bounce, hold or re-establish a normal landing attitude
and add thrust as necessary to control the rate of descent. Avoid rapid
pitch rates in establishing a normal landing attitude.
CAUTION: Tail strikes or nosewheel structural damage can
occur if large forward or aft control column movements
are made prior to touchdown.
When a bounced landing occurs, consider initiating a go-around by use of
normal go-around procedures. Do not retract the landing gear until a
positive rate of climb is established because a second touchdown may
occur during the go-around.
Comparative crashes in different Forum sections)
News Shooter
Rules?
We don't need rules, just judgements.
It's kind of like news papers with sports sections and Financial sections. Sometimes the reader interest is so high that an item makes the front page headline.
OTOH we have in the US Telly the 6 O'clock news and the news at 11 pm. If your really a local you watch both. Otherwise like me you just sample what's hot.
So let the reader (browsers decide what's hot) and the Mods second guess us all
I just want to understand the rules. Thanks for any help you can give me.
We don't need rules, just judgements.
It's kind of like news papers with sports sections and Financial sections. Sometimes the reader interest is so high that an item makes the front page headline.
OTOH we have in the US Telly the 6 O'clock news and the news at 11 pm. If your really a local you watch both. Otherwise like me you just sample what's hot.
So let the reader (browsers decide what's hot) and the Mods second guess us all