Comes After Three Incidents In Three Weeks

Prompted by three emergency landings over the past three weeks, on Monday Alaska Airlines announced it will inspect its 40-plane fleet of Boeing 737-400 aircraft for possible problems related to flap deployment.

The Seattle Post-Intelligencer reports three incidents related to improper flap deployment -- on January 11, 20, and 26 -- involving two 737-400 Combis prompted the inspections. In all three cases, the flaps failed to fully deploy on landing... prompting one diversion to an airport with a longer runway.

Airline spokesman Paul McElroy said Alaska won't ground the planes. Inspection of the entire 737-400 fleet is expected to last two weeks.

"This aircraft is certified to land with the flaps fully up -- it's not preferable, but it could," McElroy said. "And flight crews are trained for that."

On January 20, Alaska Flight 64 was approaching the short, exposed runway in Wrangell, AK when the pilot discovered the Combi's flaps would not extend past 10 degrees, instead of full 40 degree deployment. As the aircraft needs a longer runway to land with only partial flaps, the crew diverted to Ketchikan, where the plane made a safe landing. The pilot declared an emergency, as is called for in such cases.

That aircraft was flown to Anchorage for repairs, and was put back into service 22 hours later. The same Combi had encountered similar difficulties on January 11, and made an emergency landing in Anchorage then, according to Alaska Airlines.

On Saturday, Flight 64 -- same route, but a different Combi -- declared an emergency on approach to land at Ketchikan.

"Once the second incident occurred, we decided to inspect all the others, to see whether they have the same hardware-wear issue," McElroy said. The problem was traced to the housing for the machinery that deploys the flaps.

McElroy stressed the repairs weren't "required by the manufacturer or the FAA. We're doing it just to improve reliability." None of the emergency landings resulted in any injuries or property damage.

The airline did not disclose the incidents, until the P-I contacted the airline Monday in follow-up to reader comments. Alaska was not required to notify the FAA or NTSB, according to McElroy, but personnel with both agencies, along with Boeing, have since been contacted.

Five of Alaska's 40 -400s are Combis, which have been converted to carry both cargo and passengers (an older, 737-200 Combi, is shown above.) It is not known whether the problem may be unique to the Combi fleet.

FMI: www.alaskaair.com, www.faa.gov