WASHINGTON, March 3 U.S. aviation regulators on
Monday proposed a fix for some Boeing 737 planes to
ensure that a faulty altimeter does not cause the automatic
throttle system to unexpectedly cut engine speed.
The Federal Aviation Administration said the changes to
cockpit automation, if adopted, would affect 497 Boeing 737s,
specifically the 600 and its later models. Chicago-based Boeing
said another 778 jets would be affected if aviation regulators
outside the United States adopt the FAA proposal.
Boeing said in an email to Reuters that the FAA's proposed
rule would order actions the company had previously recommended
A plane's altimeter measures altitude. The fix would prevent
a false reading from triggering the plane's automatic throttle
control to reduce speed on landing, possibly leading to a loss
of control, the FAA said.
A Boeing spokesman said he did not have any information on
how much the changes could cost. It was not immediately clear
who would be responsible for implementing the changes if
In 2009, a Turkish Airlines Boeing 737-800 crashed as it was
nearing an Amsterdam airport when a faulty altimeter caused the
automatic pilot to cut power and the pilots failed to notice in
time, according to a Dutch safety board report. Nine of the 135
people onboard were killed.
Boeing said that since 2010 its production of the 737s has
included software changes to the flight control computer and a
cockpit voice warning pilots when airspeeds are low.
Questions about pilot reliance on automated flight controls
in large passenger jets also were raised after the July crash of
a Boeing 777 into a seawall at San Francisco airport. Three
The pilots of the Asiana Airlines flight realized too late
that the plane was flying too low and slowly even though they
had set the auto-throttle control system to keep the plane at a
The FAA is seeking public comment on the 737 proposal for 45
days. A timeline for final approval was not immediately clear,
but the changes would need to be implemented in three years if
approval is granted.