Cyprus-Forum.com

[Kikapu]

Why waste time here talking about it when you can get all the info here: http://www.airdisaster.com/

Thanks for the link, Raymanoff.

I takes a very long time to get the investigative report as to the cause of the crash. I can either wait at least six months for it, or try to make some educated guess as to what may have happened which is what I like to try and figure out before the full investigative report comes out. It is also a nice break away from politics too.!

[Kikapu]

Hi Kikapu,

I am not at all familiar with this aircraft but it is important to understand that every aircraft has its peculiarities.

The MD-11 has a rather substantial design flaw in that the aircraft has a significantly reduced tailplane. As a result, a Longitudinal Stability Augmentation System (LSAS) was fitted to assist with Pitch control. The consequences for LSAS failure on this aircraft could have caused this accident as the aircraft would not have enough elevator trim to execute a missed approach or Go Around procedure, especially if the aircraft had an aft Centre of Gravity (CoG) at the time. This aircraft also has a history of tailstrike, which means that the pilots may have pushed the nose down after the initial bounce, thus causing Pilot Induced Oscillation (PIO) which is the tendency to apply rapid over corrections in elevator control inputs in the opposite direction (pushing the nose down) after bouncing in order to raise the tail and avoid a possible tailstrike scenario, thus resulting in hitting the ground very hard on the nose wheel.

I am not aware if there was any cargo on board. If the aircraft was completely empty, then the aircraft could very well have an aft CoG but within limits. This too could be a contributing factor. If there was cargo on board then we should also be open to the possibility of cargo shift aft resulting in the CoG moving aft outside of design limitations. As the aircraft is also arriving at its destination it would have also a minimum amount of fuel on board. It basically would only be carrying Fixed and Variable Reserve fuel as all the Flight Fuel (FF) would have been burned thus causing the CoG to also move aft, although pilots must always ensure that the aircraft is balanced throughout the whole flight by entering the data on the Load and Trim Sheet, but add Cargo Shift into the fold, then you have a tail heavy aircraft. Cargo must always be properly restrained but Cargo Shift has occurred in the past.

The following is from the MD-11 Flight Manual:

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.

Another contributory factor would also have to be the strong winds. When I go back to work, I will print the aerodrome layout and I am still trying to find the Aerodrome MET Report (METAR) of the actual conditions at the time of the accident. This is important as I would then be able to work out what the Cross Wind (XW) and Head Wind components were on impact. Wind Gusts could also likely be a contributor, because so often in strong wind situations (74kts), the wind is not always constant but is gusting, and we all know that Lift is directly proportional with Airspeed over the wing. A strong crosswind could have also contributed to the inadvertent roll as Lift is always greater on the side the wind is blowing from if this is not counteracted.

It is important to also understand that all of this is largely guesswork or speculation. Aircraft Investigation is very complex and intense and I am only a pilot who has not flown this type.

Kikapu, I am just shy of 9,500 flight hours. The first aircraft I ever flown was a Piper Warrior and Piper Arrow Aircraft. I was then trained on Pilatus PC-9, Machi MB-326 before being assigned to the AP-3C Orion. I now fly De Havilland Dash 8-202/315 aircraft. Most of my experience was on Orion aircraft. So I know very little about the MD-11.

This accident is very much an eye opener for all pilots. It just goes to show how quickly things can turn real ugly. In all my flying experience I too have managed to bounce an aircraft along the runway many times. I have also had atrociously hard landings, but these days it does not take much for me to conduct a missed approach.

Thanks for your input as always, Paphitis. I knew you could give us few more details than I could on the technical side and the importance of having the correct Weight & Balance of an aircraft during take off, in flight and landing. With 9,500 hours, you have definitely earned your wings.!

I took the view, that if the strong head winds were accurate, that was going to play a major part in making the plane “bounce” soon after touchdown as the speed of the airflow over the wings were changing to “too much” to “too little” each time the plane bounced and then re bounced again. I agree with you, that a strong cross wind would lift the wing it is striking (windward side) more than the other side (leeward side), using some sailing terminology, that would cause the plane to flip over, but seeing the footage, the plane only flipped over after the second bounce, which I believe the plane had staled at this point and was no longer able to fly and the lack of pilots able to control pitch or roll at this point, the aircraft did what it wanted to do. The results was deadly for the 2 crew members. What the plane did upon landing, it was like bouncing a flat stone on the water across a pond or a lake. We have all done that, right.!

Since you mentioned having had flying hours in a Pilatus PC-9, ironically, on the same day as the FedEx MD-11 crash, there was another air crash in Montana, USA, a Pilatus PC-12 that killed all aboard, all 14 of them. You are asking yourself, "yeah but, there are no 14 seats on that plane", which is true. 7 of the dead were kids, so I guess some were riding on parents laps. Another irony of the whole tragedy was, that it crashed into a cemetery short of the runway.

Correct me if I'm wrong, but a single pilot can only fly up to a 10-seat aircraft (prop), unless it is a Lear Jet, then you would require 2 pilots no matter the amount of seats the plane holds. But having 14 people on a plane, did the pilot not violate the 10-seat rule for this aircraft, even if it was within the load weight limits because there were 7 kids, by having more passengers than seats for them, although the airliners allow under 2 year olds to ride on parents laps as well, but then again, there are at least 2 pilots in any carrier planes.



Pilatus PC-12

[Paphitis]

Why waste time here talking about it when you can get all the info here: http://www.airdisaster.com/

Thanks for the link, Raymanoff.

I takes a very long time to get the investigative report as to the cause of the crash. I can either wait at least six months for it, or try to make some educated guess as to what may have happened which is what I like to try and figure out before the full investigative report comes out. It is also a nice break away from politics too.!

Kiks,

Do you watch Air Crash Investigations?

Also, feel free to post more aviation accidents/incidents and we could both try our best to get to the bottom of it all.

I don't know about you, but I'm dieing for BigOz also giving us his version of what might have caused the FedEx MD-11 crash.

[Kikapu]

Why waste time here talking about it when you can get all the info here: http://www.airdisaster.com/

Thanks for the link, Raymanoff.

I takes a very long time to get the investigative report as to the cause of the crash. I can either wait at least six months for it, or try to make some educated guess as to what may have happened which is what I like to try and figure out before the full investigative report comes out. It is also a nice break away from politics too.!

Kiks,
Do you watch Air Crash Investigations?

No, what is it.?

Also, feel free to post more aviation accidents/incidents and we could both try our best to get to the bottom of it all.

I think it is very educational to ponder and write about this stuff. It may even help those who are not aviation minded, like Oracle, to have some idea how an aircraft works. Oracle just does her 3 times crosses and then downs a strong shot of whisky to calm her nerves before getting on a plane.!

I don't know about you, but I'm dieing for BigOz also giving us his version of what might have caused the FedEx MD-11 crash.

I have tried to get BigOz to talk about flying long before, but he has not shown any interest, which is very unusual for any person who is into aviation, specially as much as he claims to be involved. But I always extend invitation for him to join in the conversation on air crashes so that we can throw different ideas around. Skyvet is another who has not joined in yet, who is also/was a pilot.!

[Paphitis]

I took the view, that if the strong head winds were accurate, that was going to play a major part in making the plane “bounce” soon after touchdown as the speed of the airflow over the wings were changing to “too much” to “too little” each time the plane bounced and then re bounced again. I agree with you, that a strong cross wind would lift the wing it is striking (windward side) more than the other side (leeward side), using some sailing terminology, that would cause the plane to flip over, but seeing the footage, the plane only flipped over after the second bounce, which I believe the plane had staled at this point and was no longer able to fly and the lack of pilots able to control pitch or roll at this point, the aircraft did what it wanted to do. The results was deadly for the 2 crew members. What the plane did upon landing, it was like bouncing a flat stone on the water across a pond or a lake. We have all done that, right.!

The plane may have stalled. However it is a performance requirement to maintain a minimum Vat (Velocity at Threshold) of 1.3 Vs (Stall Velocity), in the landing configuration. This is to ensure adequate Climb Out Performance in the event of a Go Around and also ensure an Obstacle Clearance Climb Gradient which would clear all surveyed Obstacles with a performance liability of an Engine failing on Go Around (assuming zero visibility i.e in cloud). This is an ICAO requirement. But a wind of 74 Knots with + or - 30Knot wind gusts could potentially be enough to cause the aircraft to lose enough airspeed bringing it close to the stall. Also, a small amount of rudder control input, when stalled, could cause the aircraft to enter a spiral spin. I'm not saying that the violent roll on the runway was a spiral spin, but it is possible.

The way the aircraft violently pitched up and then pitched down may also indicate the possibility of Pilot Induced Oscillation (PIO) or over correcting from the initial bounce since the pilot would've been weary of the possibility of tailstrike.

It would also be very interesting to see the position of the aircraft's Centre of Gravity and whether this was within the allowable Mean Aerodynamic Chord or envelope. If not, then the aircraft may not have been balanced and this may have caused major instability resulting in a drastic change the aircraft's flight characteristics. Cargo Shift could have caused this.

After the initial bounce, I would have instantly advanced all throttles forward, and selected a nose up attitude for a Go Around (GA). Bear in mind that in high wind situations, it is important to monitor airspeed like a hawk, and personally I would've come in a little faster than normal, so that I can be sure that I am able to very quickly achieve a +ve Rate of Climb on Go Around. In fact, at the slightest hint of any trouble, even before the wheels touched, I personally would like to think that I would initiate a GA. So it would be interesting to find out from the report on whether the pilots initiated a GA but could not climb out due to stall or not having adequate elevator trim to maintain a 10 degree Pitch Up due to LSAS failure...

Since you mentioned having had flying hours in a Pilatus PC-9, ironically, on the same day as the FedEx MD-11 crash, there was another air crash in Montana, USA, a Pilatus PC-12 that killed all aboard, all 14 of them. You are asking yourself, "yeah but, there are no 14 seats on that plane", which is true. 7 of the dead were kids, so I guess some were riding on parents laps. Another irony of the whole tragedy was, that it crashed into a cemetery short of the runway.

Correct me if I'm wrong, but a single pilot can only fly up to a 10-seat aircraft (prop), unless it is a Lear Jet, then you would require 2 pilots no matter the amount of seats the plane holds. But having 14 people on a plane, did the pilot not violate the 10-seat rule for this aircraft, even if it was within the load weight limits because there were 7 kids, by having more passengers than seats for them, although the airliners allow under 2 year olds to ride on parents laps as well, but then again, there are at least 2 pilots in any carrier planes.

CAR 5.01 states that:

Multi-pilot aeroplane means an aeroplane that is required by its flight manual to be flown by 2 or more pilots; and

Single pilot aeroplane means an aeroplane that is not a multi-pilot aeroplane.

http://casa.gov.au/rules/index.htm

In short, the aircraft flight manual specifies the number of crew required to safely operate an aircraft. The flight crew members therefore are required to hold the aircraft endorsement (CAO 40.1.0) to operate and log flight time accordingly in accordance with the guidance CASA provides.

The Pilatus PC-12 is a Single Pilot Aircraft in accordance with its Flight Manual. The Royal Flying Doctor Service (RFDS) in Australia operate a fleet of PC-12 Medivac aircraft and these are always Single Pilot. I could be mistaken, but I think the Lear Jet might also be Single Pilot.

http://www.flyingdoctor.net/PC-12-Aircraft.html

An operator may impose additional training and/or qualification requirements and this could also be a contractual requirement from third parties. In other words, if a company has a contractual obligation for lets say fly in fly out operations for a mining company, then the client may stipulate Multi Crew Operations as a contractual requirement regardless of the fact that the aircraft Flight Manual only stipulates a Single Pilot.

[Raymanoff]

Turkish Airlines crash was caused by windsheer...

[Paphitis]

Why waste time here talking about it when you can get all the info here: http://www.airdisaster.com/

Thanks for the link, Raymanoff.

I takes a very long time to get the investigative report as to the cause of the crash. I can either wait at least six months for it, or try to make some educated guess as to what may have happened which is what I like to try and figure out before the full investigative report comes out. It is also a nice break away from politics too.!

Kiks,
Do you watch Air Crash Investigations?

No, what is it.?

Also, feel free to post more aviation accidents/incidents and we could both try our best to get to the bottom of it all.

I think it is very educational to ponder and write about this stuff. It may even help those who are not aviation minded, like Oracle, to have some idea how an aircraft works. Oracle just does her 3 times crosses and then downs a strong shot of whisky to calm her nerves before getting on a plane.!

I don't know about you, but I'm dieing for BigOz also giving us his version of what might have caused the FedEx MD-11 crash.

I have tried to get BigOz to talk about flying long before, but he has not shown any interest, which is very unusual for any person who is into aviation, specially as much as he claims to be involved. But I always extend invitation for him to join in the conversation on air crashes so that we can throw different ideas around. Skyvet is another who has not joined in yet, who is also/was a pilot.!

Air Crash Investigation is a series of documentaries about major Air Disasters around the world and the fascinating procedures and techniques used by Air Crash Investigation Teams in order to piece together the chain of events that led to the crash.

You would absolutely love it!

Here are some episodes:

http://video.google.com/videoplay?docid ... 4703379668

The above is all about the KLM and Pan Am disaster in Tenerife. This is an excellent case study for Crew Resource Management we talked about in the THY thread.

http://video.google.com/videoplay?docid ... 9830845243

http://www.dailymotion.com/video/x5lrn4 ... shortfilms

http://www.guba.com/watch/3000140407

http://www.youtube.com/watch?v=7A5W9YC-1EU

This stuff is certainly very educational. A pilot's education never ends.

I urge everyone to watch the above.

[Kikapu]

I took the view, that if the strong head winds were accurate, that was going to play a major part in making the plane “bounce” soon after touchdown as the speed of the airflow over the wings were changing to “too much” to “too little” each time the plane bounced and then re bounced again. I agree with you, that a strong cross wind would lift the wing it is striking (windward side) more than the other side (leeward side), using some sailing terminology, that would cause the plane to flip over, but seeing the footage, the plane only flipped over after the second bounce, which I believe the plane had staled at this point and was no longer able to fly and the lack of pilots able to control pitch or roll at this point, the aircraft did what it wanted to do. The results was deadly for the 2 crew members. What the plane did upon landing, it was like bouncing a flat stone on the water across a pond or a lake. We have all done that, right.!

The plane may have stalled. However it is a performance requirement to maintain a minimum Vat (Velocity at Threshold) of 1.3 Vs (Stall Velocity), in the landing configuration. This is to ensure adequate Climb Out Performance in the event of a Go Around and also ensure an Obstacle Clearance Climb Gradient which would clear all surveyed Obstacles with a performance liability of an Engine failing on Go Around (assuming zero visibility i.e in cloud). This is an ICAO requirement. But a wind of 74 Knots with + or - 30Knot wind gusts could potentially be enough to cause the aircraft to lose enough airspeed bringing it close to the stall. Also, a small amount of rudder control input, when stalled, could cause the aircraft to enter a spiral spin. I'm not saying that the violent roll on the runway was a spiral spin, but it is possible.

The way the aircraft violently pitched up and then pitched down may also indicate the possibility of Pilot Induced Oscillation (PIO) or over correcting from the initial bounce since the pilot would've been weary of the possibility of tailstrike.

It would also be very interesting to see the position of the aircraft's Centre of Gravity and whether this was within the allowable Mean Aerodynamic Chord or envelope. If not, then the aircraft may not have been balanced and this may have caused major instability resulting in a drastic change the aircraft's flight characteristics. Cargo Shift could have caused this.

After the initial bounce, I would have instantly advanced all throttles forward, and selected a nose up attitude for a Go Around (GA). Bear in mind that in high wind situations, it is important to monitor airspeed like a hawk, and personally I would've come in a little faster than normal, so that I can be sure that I am able to very quickly achieve a +ve Rate of Climb on Go Around. In fact, at the slightest hint of any trouble, even before the wheels touched, I personally would like to think that I would initiate a GA. So it would be interesting to find out from the report on whether the pilots initiated a GA but could not climb out due to stall or not having adequate elevator trim to maintain a 10 degree Pitch Up due to LSAS failure...

Since you mentioned having had flying hours in a Pilatus PC-9, ironically, on the same day as the FedEx MD-11 crash, there was another air crash in Montana, USA, a Pilatus PC-12 that killed all aboard, all 14 of them. You are asking yourself, "yeah but, there are no 14 seats on that plane", which is true. 7 of the dead were kids, so I guess some were riding on parents laps. Another irony of the whole tragedy was, that it crashed into a cemetery short of the runway.

Correct me if I'm wrong, but a single pilot can only fly up to a 10-seat aircraft (prop), unless it is a Lear Jet, then you would require 2 pilots no matter the amount of seats the plane holds. But having 14 people on a plane, did the pilot not violate the 10-seat rule for this aircraft, even if it was within the load weight limits because there were 7 kids, by having more passengers than seats for them, although the airliners allow under 2 year olds to ride on parents laps as well, but then again, there are at least 2 pilots in any carrier planes.

CAR 5.01 states that:

Multi-pilot aeroplane means an aeroplane that is required by its flight manual to be flown by 2 or more pilots; and

Single pilot aeroplane means an aeroplane that is not a multi-pilot aeroplane.

http://casa.gov.au/rules/index.htm

In short, the aircraft flight manual specifies the number of crew required to safely operate an aircraft. The flight crew members therefore are required to hold the aircraft endorsement (CAO 40.1.0) to operate and log flight time accordingly in accordance with the guidance CASA provides.

The Pilatus PC-12 is a Single Pilot Aircraft in accordance with its Flight Manual. The Royal Flying Doctor Service (RFDS) in Australia operate a fleet of PC-12 Medivac aircraft and these are always Single Pilot. I could be mistaken, but I think the Lear Jet might also be Single Pilot.

http://www.flyingdoctor.net/PC-12-Aircraft.html

An operator may impose additional training and/or qualification requirements and this could also be a contractual requirement from third parties. In other words, if a company has a contractual obligation for lets say fly in fly out operations for a mining company, then the client may stipulate Multi Crew Operations as a contractual requirement regardless of the fact that the aircraft Flight Manual only stipulates a Single Pilot.

Thanks one more time for the above explanations, Paphitis. I agree with your assessment of the below quote.

After the initial bounce, I would have instantly advanced all throttles forward, and selected a nose up attitude for a Go Around (GA). Bear in mind that in high wind situations, it is important to monitor airspeed like a hawk, and personally I would've come in a little faster than normal, so that I can be sure that I am able to very quickly achieve a +ve Rate of Climb on Go Around. In fact, at the slightest hint of any trouble, even before the wheels touched, I personally would like to think that I would initiate a GA. So it would be interesting to find out from the report on whether the pilots initiated a GA but could not climb out due to stall or not having adequate elevator trim to maintain a 10 degree Pitch Up due to LSAS failure...

I got a feeling, that after the first bounce, power was reduced to sit the plane down, but at the time of the second bounce where strong headwinds over the wings would have help create lift yet still, it is possible once the second bounce was in motion, the aircraft lost all lift and came crashing down listing to the port side, otherwise, more power added would have assisted the plane to generate lift to do a Go Around as you suggested.

[Kikapu]

Air Crash Investigation is a series of documentaries about major Air Disasters around the world and the fascinating procedures and techniques used by Air Crash Investigation Teams in order to piece together the chain of events that led to the crash.

You would absolutely love it!

Here are some episodes:

http://video.google.com/videoplay?docid ... 4703379668

The above is all about the KLM and Pan Am disaster in Tenerife. This is an excellent case study for Crew Resource Management we talked about in the THY thread.

http://video.google.com/videoplay?docid ... 9830845243

http://www.dailymotion.com/video/x5lrn4 ... shortfilms

http://www.guba.com/watch/3000140407

http://www.youtube.com/watch?v=7A5W9YC-1EU

This stuff is certainly very educational. A pilot's education never ends.

I urge everyone to watch the above.

This is great stuff, thanks a lot. Now I have more interesting things to watch than porn.!

[Kikapu]

Turkish Airlines crash was caused by windsheer...

TK 1951 crash was discussed at lenghs on this thread....
http://www.cyprus-forum.com/viewtopic.p ... sc&start=0

Where did you get this information from, Raymanoff.?

The last report that came out on March 4th was this.

"Bad altimeter a factor in Netherlands plane crash

By TOBY STERLING, Associated Press

Writer Toby Sterling, Associated Press Writer – 9 mins ago

AMSTERDAM – Investigators said Wednesday a faulty altimeter played an important role in a Turkish Airlines crash that killed 9 people in the Netherlands.

The Dutch Safety Authority said the plane was being landed on automatic pilot and the problem with the altimeter, a device that measures altitude, led to a loss of airspeed before the crash.

The Boeing 737-800 carrying 135 passengers and crew went down in a muddy field one kilometer (less than a mile) short of the runway at Amsterdam's Schiphol Airport shortly before it was due to land on Feb. 25.

Chief investigator Pieter van Vollenhoven said the airplane had twice before experienced problems with its altimeter. Boeing has been instructed to warn clients of the problem, he said.

At 1950 feet (around 700 meters) "the airplane's left radio altimeter suddenly registered a change in altitude" of negative 8 feet (about 2 meters). "It didn't only register it, but passed it on to the automatic steering system," Van Vollenhoven said.

Van Vollenhoven said it was not unusual to land a plane on autopilot.

According to conversation recorded between the plane's captain, first officer and an extra first officer on the flight, the pilots noticed the faulty altimeter but didn't consider it a problem and didn't react, Van Vollenhoven said.

Gas to the engines was reduced and the plane lost speed, decelerating until, at a height of 450 feet (150 meters) the plane was about to stall, and warning systems alerted the pilots.

"From the "black box" (data recorders) it appears that then the pilots immediately gave gas, full gas, however it was too late to recover," Van Vollenhoven said.

He said that the pilots had been unable to see the runway at the time the plane began its descent due to weather conditions — cloudy with a light rain.

The plane fell into a freshly plowed field, striking the ground tail first and breaking into three pieces."

http://news.yahoo.com/s/ap/20090304/ap_ ... lane_crash