Europe's safety regulator has expanded an emergency airworthiness directive for the Leonardo Helicopters AW169 to incorporate its tail rotor bearings.
The AW169 medium-twin has been under scrutiny since a fatal crash in the UK on 27 October of a VIP-roled example in which five people were killed.
UK investigators have so far been unable to determine the cause of the accident, which happened shortly after take-off, but have detailed an apparent loss of yaw control, with their focus on the tail rotor controls.
In its latest update, the European Aviation Safety Agency has extended its airworthiness directive to include an examination of the AW169's tail rotor duplex bearing, which must be performed before the helicopter's next flight.
That directive has now been updated again, stipulating a breakaway torque check of the bearing, as well as a inspection and re-installation of the servo-actuator's castellated nut.
An earlier iteration of the directive, issued on 9 November, specified an urgent inspection of the tail rotor servo-actuator assembly.
The fifth paragraph of this story has been updated to included new information from EASA.