The National Transportation Safety Board is recommending that its European counterpart require a helicopter manufacturer to review the design of a fuel control lever blamed for a crash in Alaska.

The NTSB says the European Aviation Safety Agency should also require review of a track on Eurocopter's AS350-series helicopter and require modification to ensure that the fuel flow control lever is protected to prevent unintentional movement.

A Eurocopter AS350B2 helicopter crashed on April 15, 2008, about 34 miles east of Chickaloon, Alaska, killing four people.

The NTSB says the probable cause was loss of engine power due to overspeed of the turbine engine, precipitated by the inadvertent movement of the fuel flow control lever by a front-seat passenger.

The Eurocopter Group is a global helicopter manufacturing and support company with facilities in France, Germany and Spain.