AD NUMBER: 2018-02-07

PRODUCT: Model TH-1F, UH-1B, UH1F, UH-1H, and UH-1P helicopters with a Helicopter Technology Company (HTC) main rotor (M/R) blade installed.

ACTION: Final rule; request for comments.

SUMMARY: This AD requires cleaning and visually inspecting the M/R blades and, depending on the outcome of the inspection, repairing or replacing the M/R blades.

This AD is prompted by a report of an M/R blade with a fatigue crack in the grip plate and doublers at the blade retention bolt hole.

DATES: This AD becomes effective February 1, 2018. Comments must be received on this AD by March 19, 2018.

COST: The FAA estimates that this AD affects 10 helicopters of U.S. Registry and that labor costs average $85 per work-hour.

Based on these estimates, the FAA estimates the following costs:

• Cleaning and performing all inspections of a set of M/R blades (2 per helicopter) requires 0.5 work-hour for a cost of $43 per helicopter and $430 for the U.S. fleet per inspection cycle.
• Replacing an M/R blade requires 12 work-hours and parts cost $86,000 for a total cost of $87,020 per blade.
• Reporting the inspection results required by this AD will require about 0.5 work-hour for a cost of $43 per helicopter and $430 for the U.S. fleet.

FMI: AD