Says Both To Blame For Engine-Out Takeoff Crash

The operator of a Mistubishi MU-2 involved in a fatal December 2005 takeoff accident has sued the planemaker, stating it knew the turboprop twin was uncontrollable in takeoff configuration in the event of engine failure. The lawsuit also alleges enginemaker Honeywell International knew of a potential problem with the MU-2's engines, but did not require modifications to solve the problem.

Two pilots were lost shortly after takeoff from Terrance, British Columbia on December 20, 2005. A recent report by Canada's Transport Safety Board placed partial blame for the accident on the loss of an engine on takeoff.

"During the takeoff, the left engine combustion chamber plenum split open due to a fatigue crack," said the report, cited by The Canadian Press. "The rupture was so extensive that the engine flamed out."

TSB investigators also noted 60 similar reports over a 30-year period of cracked or damaged plenums in the Honeywell turbines used in the MU-2. The manufacturer changed the component design in 1977, but did not require modifications to powerplants already in service.

Both pilots were employees of the former Nav Air Charter Inc., which had its operating license pulled by Transport Canada shortly after the accident for failure to provide a valid Canadian aviation document.

Shortly after TSB released its final report on the accident, representatives with Nav Air filed suit in British Columbia Supreme Court against Mitsubishi and Honeywell, seeking compensation for the lost plane, employees and cleanup of the accident scene.

Nav Air says Mitsubishi's operating manual for the high-performance turboprop advises pilots to set flaps to 20 degrees in certain takeoff situations, even though the planemaker knew the aircraft would become uncontrollable in that configuration if an engine lost power.

The lawsuit also claims Honeywell contributed to the accident, stating the company "failed to use reasonable care in the design, manufacture, distribution and after-market support of the engine and, more particularly, the combustion plenum."

Neither company has yet responded to the suit, according to the CP.

In its report, TSB makes four recommendations for safe operation of the MU-2, including warning operators of potential problems with the original plenums, as well as reinforced training procedures on engine-out operations.

A popular choice with cargo operators due to its low cost and high speed, the MU-2 has a history of accidents that have led some lawmakers and officials to call for the aircraft's grounding. The MU-2's flight characteristics at low speeds and altitudes -- what is traditionally called "slow flight" -- are frequently cited by critics of the aircraft.

Mitsubishi has acknowledged the MU-2 poses additional challenges to a pilot unfamiliar with the aircraft's idiosyncrasies, and supports requiring pilots to earn a type-rating for the aircraft -- something the FAA and other regulatory agencies have, to date, stopped short of doing.

FMI: www.tsb.gc.ca