* Faulty altimeter led to plane's reduced speed
* Air traffic control gave insufficient directions
* Boeing has since implemented altimeter measures
* Turkish Airlines disputes pilot error to blame
(Adds Boeing, Turkish Airlines comments)
By Aaron Gray-Block
AMSTERDAM, May 6 A faulty altimeter and pilot
error led to the Turkish Airlines crash at Amsterdam last year,
Dutch investigators said on Thursday, urging the industry to
improve training and reporting of technical glitches.
Nine people were killed when flight TK 1951 from Istanbul
crashed on approach to Schiphol Airport on Feb. 25, 2009.
Investigators had earlier said a faulty altimeter had shut down
the engine of the Boeing (BA.N) 737-800 before it crashed.
But the Dutch Safety Board said in its final report that a
combination of the altimeter problems, bad reactions from the
Turkish Airline (THYAO.IS) pilots, plus a loss of speed and
insufficient air traffic control directions led to the crash.
The board said that due to the failing of the altimeter, the
airliner automatically lost speed, dropping below the minimum
velocity needed to avoid the risk of engines stalling.
The pilots failed to intervene either adequately or early
enough at several crucial moments of the descent, said safety
board director Pieter van Vollenhoven, who called for better
international pilot training to deal with emergencies.
In response, Boeing said accidents rarely result from a
single failure or action and added it has since taken several
steps to prevent the same chain of events that led to the crash.
These include measures to reduce the likelihood of
discrepant altimeters, make other systems more tolerant of
erroneous readings and provide additional indicators to assist
flight crews monitor altimeters and air speed.
Turkish Airlines disputed the safety board's finding that
approach stabilisation played a role in the crash and that the
crew could have saved the aircraft after a stall warning was
"Even though the crew promptly reacted, autothrottle kicked
back unexpectedly. The second attempt by the crew, after
disengaging the autothrottle, to advance thrust levers was
succesful but too late," the airline said in a statement.
Safety board chief Van Vollenhoven said at a news conference
that via "an exceptionally unfortunate combination of
circumstances" the flight crew received insufficient directions
from air traffic control on how to approach the runway.
The pilots were advised to conduct the approach via a
frequently-used "short turn-in", but were not advised to also
descend, masking the malfunctioning of the plane's autothrottle.
Van Vollenhoven added Boeing and many airlines were aware of
problems with the radio altimeter system, but that this had been
considered a technical rather than safety issue. Also, in most
cases, pilots did not report problems with the altimeter system.
Dutch law office AKD Prinsen Van Wijmen (AKD) said last
September survivors of the crash have agreed to its advice to
ask Clifford Law Offices to start compensation proceedings in
the United States against Boeing.
Frans Vreede at law firm AKD said he was most concerned by
findings that an altimeter comparator was not installed in the
plane to ensure the right-hand altimeter, which was operating
correctly, overrode the left-hand altimeter or alerted pilots.
Passengers suffered broken backs and shattered legs or
psychological trauma, Vreede said. The case is still pending.
Evert van Zwol, chairman of the Dutch pilots association,
welcomed recommendations for improved training, saying that
training should be repeated annually or once every two years.
(Additional reporting by Ayla Jean Yackley in Istanbul; Editing
by Mark Heinrich)