Ministry Warns Skymark Airlines Over Plane Maintenance

TOKYO, April 13_(Kyodo) - (EDS: UPDATING WITH MORE INFO)

The Land, Infrastructure and Transport Ministry issued a strict written warning to Skymark Airlines on Friday for operating three jetliners without conducting necessary maintenance checks, ministry officials said.

The required maintenance includes checks of the main wings' leading edge flap, used for landing, and the cleansing of air-control systems, but the budget airline flew three Boeing 767s for as much as up to two years and eight months after the legal deadline for the maintenance had passed.

The Tokyo-based airline, established in 1996, became aware of the lack of some maintenance checks on March 27, but it continued the operations for two days for 24 domestic flights, claiming such shortcomings would have only "a small impact" on flight safety, the officials said.

The ministry summoned Ryuji Ide, a Skymark senior official in charge of aircraft maintenance, and demanded that the airline find out the cause of the incident and report to the ministry by April 25 on preventive measures.

Skymark learned March 23 that it had failed to check one of the aircraft during an April 2006 maintenance for oil levels in a motor that drives the main wings' leading-edge flaps, used during take-offs and landings, according to the ministry.

The airline then conducted the check and looked for more items that had been left unchecked on other planes. By March 27, it had found out that on three Boeing 767s, the devices fixing the flaps had not been tested for about four months, and that the filters for refrigerators installed in the galleys had not been cleaned for up to two years and eight months.

A maintenance worker allowed the three planes to operate for the next two days -- March 28 and 29 -- for the 24 flights, including those connecting Tokyo and Fukuoka, thinking that the checks should be made during a next regular inspection, according to the ministry.

A supervisor instructed the worker to conduct checks soon but did not stop the aircraft from being used for the flights.

Skymark said it "greatly regrets" having flown the planes without proper maintenance checks and promised to improve on its maintenance practices.

"We want to work on preventing the recurrence of a similar instance by improving our maintenance system," an airline official said.

The transport ministry issued a business improvement order to Skymark last year following a series of mishaps and troubles, including mistakes in aircraft servicing and the violations of internal regulations on flight operations.