MD-11 instability
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Join Date: Jul 2001
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MD-11 instability
Hi,
can anybody here (maybe a MD-11 pilot) confirm that the MD-11 is really that unstable during approach?
Is it really that hard to fly? I´ve heard that the FedEx crash at EWR was caused by the instability of the MD-11.
Is this instability a saftey issue I should concern about as a passanger???
Thanks for any answers and information,
Daniel
can anybody here (maybe a MD-11 pilot) confirm that the MD-11 is really that unstable during approach?
Is it really that hard to fly? I´ve heard that the FedEx crash at EWR was caused by the instability of the MD-11.
Is this instability a saftey issue I should concern about as a passanger???
Thanks for any answers and information,
Daniel
Join Date: May 1999
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Limited knowledge of the MD11 - but I understand that in order to reduce drag (= less fuel) one of the modifications made to the DC10 when it became the MD11 was to reduce the size of the Horizontal Stab (look at the rear of two next to each other and you will notice this quite easily). This does have the effect of reducing the natural stability of an aircraft, and some clever software in the flight control system copes with this to give the pilots the same (v good apparently) flying characteristics of the DC10.
Should you be worried? No.
Should you be worried? No.
Join Date: Aug 2000
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52049er is more or less right. The stabilizer area was reduced by one 3rd compared to the DC-10. It was assumed by the MDC engineers that the longer arm of the longer fuselage would compensate the stability loss. Unfortunately, once more the engineers got it wrong. Flight tests revealed an unstable aircraft in pitch. No problem, just put a bunch of computers and everything will be sorted out 
On the MD-11 they are called LSAS, longitudinal stability augmentation system.
Just a few tech infos, the MD-11 now carries fuel in the stab for C.G. adjustment. Also the elevators have slots in front of them that open when the elevators are activated.
Now, is the MD-11 less stable? YES
Afraid? Well, no
On the MD-11 they are called LSAS, longitudinal stability augmentation system.
Just a few tech infos, the MD-11 now carries fuel in the stab for C.G. adjustment. Also the elevators have slots in front of them that open when the elevators are activated.
Now, is the MD-11 less stable? YES
Afraid? Well, no
Join Date: Apr 1999
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Isnt the reason the FedEx crashed at Newark due to a slightly dodgy structure in the wing root that caused it to become detached after the very hard landing. Similar thing happened to another MD11 in Hong Kong recently.
On another note, I once came across a former MD11 pilot who said that the MD11 flight deck was the kinf of system Boeing tried to build with the 777. In fact I've come across few detractors amongst those who fly it. Anyone care to disagree?
On another note, I once came across a former MD11 pilot who said that the MD11 flight deck was the kinf of system Boeing tried to build with the 777. In fact I've come across few detractors amongst those who fly it. Anyone care to disagree?
