72-13-07: Drive Shaft Assemblies

72-13-07 FAIRCHILD-HILLER: Amdt. 39-1465. Applies to Models 1100 and FH-1100 helicopters certificated in all categories. Compliance required after the effective date of this AD as follows: 1. For helicopters incorporating P/N 19E49-3A or -3B engine-to-transmission drive shaft assemblies, replace the assemblies within 15 hours in service with P/N 19E49-3C assemblies which have accumulated less than 350 hours on their diaphragm end packs, or with P/N 19E49-3E assemblies. 2. For helicopters incorporating P/N 19E49-3C engine-to-transmission drive shaft assemblies with 350 hours or more in service on their diaphragm end packs, replace the assemblies with P/N 19E49-3E assemblies within the next 50 hours in service. 3. For helicopters incorporating P/N 19E49-3C engine-to-transmission drive shaft assemblies with less than 350 hours in service on their diaphragm end packs, replace the assemblies with P/N 19E49-3E assemblies prior to the accumulation of 400 hours in service.4. Within the next 50 hours in service, unless already accomplished within the last 50 hours in service and every 50 hours in service thereafter, inspect horizontal and vertical alignment, and axial end play of each drive shaft assembly in accordance with Sections 24-21-4 and 24-21-5 of Fairchild-Hiller FH-1100 Service Manual revised 1 March 1972 or alternative method approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region. When alignment or axial end-play limits are exceeded, replace components and check engine and transmission rigging in accordance with the service manual instructions. 5. The repetitive inspections required by Item 4 above may be extended to 100-hour intervals when P/N 19E49-3E assembly is installed. These inspections shall be conducted whenever a hard landing is made, the engine, the engine-to-transmission drive shaft, engine transmission support strut, or transmission isolation mount is removed or replaced. (Fairchild-Hiller Service Bulletin FH-1100-24-4 pertains to this subject.) This amendment 39-1465 revokes AD 69-15-11. This amendment is effective June 27, 1972.