AD NUMBER: 2012-17-10

PRODUCT: Various restricted category Model HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, and UH-1P helicopters with certain main rotor (M/R) blade assemblies installed.
SUBJECT: Airworthiness Directive 2012-17-10
ACTION: Final Rule, Request for Comments

SUMMARY: This AD requires inspecting the grip plates, doublers, and upper and lower surfaces of the M/R blades in the area between blade stations 24.5 and 40 for an edge void, corrosion, or a crack. This AD is prompted by several reports of fatigue cracks on M/R blades installed on Bell Helicopter Textron, Inc. (Bell) Model 212 helicopters. These same part-numbered M/R blades may also be installed on certain FAA-approved modified restricted category helicopters.

These actions are intended to detect an edge void, corrosion, or a crack on an M/R blade, which could lead to loss of the M/R blade and subsequent loss of control of the helicopter.

DATES: This AD becomes effective September 28, 2012. The FAA must receive comments on this AD by November 13, 2012.

FMI: AD