Airworthiness Directives; Bell Helicopter Textron (Bell)- manufactured Model HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-1F, UH- 1H, UH-1L, and UH-1P Helicopters; and Southwest Florida Aviation SW204, SW204HP, SW205, and SW205A-1 Helicopters

This amendment supersedes an existing priority letter airworthiness directive (AD), applicable to Bell-manufactured Model HH- 1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, and UH-1P helicopters; and Southwest Florida Aviation SW204, SW204HP, and SW205 helicopters, that currently requires modification and inspections of the vertical fin spar. This amendment requires the same modification and inspections required by the existing priority letter AD, but adds the Southwest Florida Aviation Model SW205A-1 and Utah State University UH-1H helicopters to the applicability of this AD. This amendment is prompted by accidents involving in-flight failure of the tailboom vertical fin spar. The actions specified by this AD are intended to prevent in-flight failure of the vertical fin spar and subsequent loss of control of the helicopter.