IMMEDIATE AND RECURRING INSPECTION OF42--DEGREE GEARBOX ASSEMBLY INPUT ANDOUTPUT QUILL BEVEL GEARSHAFT, ALL UH--1SERIES AIRCRAFT, TB 1-1520-210-30-02

IMMEDIATE AND RECURRING INSPECTION OF42--DEGREE GEARBOX ASSEMBLY INPUT ANDOUTPUT QUILL BEVEL GEARSHAFT, ALL UH--1SERIES AIRCRAFT, TB 1-1520-210-30-02

There have been 9 reported failures of the 42--Degree Gearbox Assembly Gearshafts on Army UH--1 aircraft, and 14 failures on UH--1 aircraft in the commercial arena. Failure of the Gearshaft is caused by bending fatigue of the gear teeth at the root. An inspection is required to detectcracks at the root of thegear teeth.