The U.S. Federal Aviation Administration (FAA) has issued a proposal to require Eurocopters with SNR tail rotor bearings to replace the bearings due to fatigue cracks.

Eurocopter France (ECF) Ecureuil models AS350 and AS355 are affected.

France's Direction Generale De L'Aviation Civile (DGAC) notified the FAA of the situation and their decision to require the equivalent of an Airworthiness Directive.

The bearings in the tail rotor's hub pitch change plate can crack, causing bearing failure and loss of control of the helicopter.

SNR (Annecy, France) manufactures the bearings, part number 6010F234M16. The customer part number is 704A33-651-190.

The helicopters were manufactured in France but are in operation worldwide. Approximately 514 of Eurocopter's Ecureuil model helicopters are being operated in the United States.

Eurocopter's Ecureuil line offers specifications of one or two Turbomeca engines and seating for up to 7.

The replacement schedule for the tail rotor bearings is now frequent: AS350B3 and AS355N helicopters must replace the bearing every 300 hours. All other Ecureuil models must replace the bearing every 1,200 hours.