AD 99-13-12 Amendment 39-11207

This amendment supersedes an existing priority letter airworthiness directive (AD), applicable to Bell Helicopter Textron Canada (BHTC) Model 206L, 206L-1, 206L-3, and 206L-4 helicopters, that currently requires visual inspections and visual checks at specified time intervals, and a fluorescent-penetrant inspection (FPI) for any cracks in the tailboom skins around the horizontal stabilizer openings. Inserting a copy of the priority letter AD into the Rotorcraft Flight Manual (RFM) is also required. This amendment revises the inspection procedures and specified time intervals mandated by the priority letter AD. This amendment is prompted by crack growth analysis that indicates the need to detect cracks before they propagate from underneath the horizontal stabilizer supports. The actions specified by this AD are intended to detect a crack in the tailboom skin that could result in separation of the tailboom from the helicopter and subsequent loss of control of the helicopter.