AD 99-02-02 64 FR 2558

This amendment supersedes an existing airworthiness directive (AD), applicable to RHC Model R22 helicopters, that currently requires initial and repetitive inspections of the forward flexplate (flexplate) at specified time intervals. This amendment also supersedes an existing priority letter AD that requires, within 25 hours time-in-service (TIS) or 15 calendar days, whichever occurs first, replacing the flexplate with an airworthy flexplate. This amendment requires the same replacement as the priority letter AD. This amendment is prompted by an accident in which the flexplate failed, causing loss of main rotor drive and rupture of the fuel tank. The actions specified by this AD are intended to prevent failure of the flexplate, which could result in failure of the main rotor drive system and subsequent loss of control of the helicopter.