Letters to the Editor
SUBJECT: MD
10 Model
FROM: Thom
DiGiacomo <PDGTDG@aol.com>
I am very disturbed about
the FAA’s certification of the Boeing MD10.
Boeing offers a retrofit
package to all those flying the DC10.
That package converts the 3-pilot, standard avionics cockpit of
the DC-10, to a 2-pilot "glass cockpit". The
reworked DC10s will carry the new designation of MD 10.
That Boeing conversion saves
the operator the cost of the third crewmember plus future training
costs, because MD-10 pilots will be able to transition to the MD11's
without recertification.
What disturbs me is that the
landing characteristics of the MD 11 are very different from the DC 10
The MD 11 has a much shorter horizontal stabilizer, making
landing more difficult than in a DC10.
MD 11 landings require excessive pilot input due to its inherent
instability, which is most apparent when it is slowed to landing speed.
Boeing and the FAA seem to
be ignoring that critical difference.
I am concerned that FAA certification might convey a false sense
of security to pilots that transition from MD10s to MD11s.
I think this decision is
misguided and should be reconsidered. My
suggestion would be to correct the horizontal stabilizer on the MD11's
along with this retrofit to bring the flying characteristics of the two
planes more closely together.
I would greatly appreciate
your comments on this issue.
EDITOR’S
REPLY:
I agree: the MD-10 and the
MD-11 should require separate pilot type-ratings; or failing that, any
airline that operates both models, should not require
pilots to be dual-qualified on both.
However,
I doubt that redesign of the horizontal stabilizer, on the MD-11, is
economically feasible. I
suspect that would be so costly it would be better to junk the MD-11s
and buy new planes
The Fed Ex MD-11 crash at
Newark, in July, 1997, was found to be a combination of bad pilot
judgment and over controlling the airplane at touchdown.
The lack of pitch stability on that plane probably made the
difference, as it apparently did in other landing accidents, such as the
one at Hong Kong, and the two at Anchorage, Alaska.
I have yet to hear the cause of the loss of the Fed Ex MD-11 at
Subic Bay, Manila. That one should be interesting, since they had a very long
landing runway (12,000 ft.). There
was another hard landing, by a Fed Ex MD-11 at Newark (same runway as
the July, ’97 crash) in Oct. 1999, that did substantial damage to the
center landing gear.
I think your concerns are
justified, not only as to the greater difficulty of landing the MD-11
safely, but also as to its hypersensitivity in the pitch mode, when
flown manually, at cruise altitude.
That defect in design, on the other end of the flight speed
envelope, has already killed and caused substantial damage. For more, see the FAQ on the
MD-11.
March,
2001
Robert J. Boser
Editor-in-Chief
AirlineSafety.Com
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