Four 737-400 Combis Experienced Similar Issues
Federal regulators have decided not
to require any changes to Boeing 737-400s to address flap extension
problems which occurred on four Alaska Airlines flights in
January... but investigators still aren't sure what caused those
As ANN reported, all four
cases involved 737-400 "Combis," planes which have special
equipment to allow them to convert back and forth between passenger
and cargo duty. A similar -200 Combi is shown at right.
In each case, the flaps could not be fully extended during
landings -- lengthening runway requirements, and triggering
emergency declarations by the pilots.
The Seattle Post-Intelligencer quotes two FAA spokespeople as
saying Alaska Airlines operation and maintenance complies with
applicable regulations. A temporary fix for the problem was made by
simply removing the doors which cover the flaps.
"The review involves looking at a
host of factors (including the functioning of wing-flap doors) that
can impact wing-flap performance," added Alaska Airlines
spokeswoman Amanda Bielawski, adding the airline has "not yet come
to any conclusions" on the exact cause of the issue.
In allowing Alaska to continue operating the planes without a
permanent solution, the FAA also acknowledges it has not found a
definitive cause for the problems last month.
"I want to re-emphasize that flaps are not necessary to safely
land an airplane," agency spokesman Allen Kenitzer told the P-I.
"But," he added, "when the flaps don't deploy and are expected,
this is not handled as routine."
Boeing says it is supporting Alaska Airlines' ongoing
"We continue to collaborate with Alaska Airlines by providing
them technical assistance during their review of 737-400 wing
flaps," said Boeing spokeswoman Liz Verdier.