70-06-02 BELL: Amdt. 39-955. Applies to all Model 204B 205A and 205A-1 helicopters and to any other helicopter incorporating tail rotor hub assembly, P/N 204-011-801-5 or -7 or P/N 204-011-701-11, -13 or -19 and to all spare tail rotor hub assemblies P/N 205-011-801-5 or -7 or P/N 204-011-701-11, -13 or -19.
Compliance required as indicated.
To prevent failure of the grip assemblies, P/N 204-011-728 or P/N 204-011-706, accomplish the following one time inspection on all tail rotor grip assemblies for proper hardness or conductivity before further flight, unless already accomplished after February 27, 1970. These inspections may be conducted with the grips installed on the helicopter. Determine the hardness of the grip assembly using a Rockwell Hardness or Eddy Current Tester, a Magnatest FM-120 (Magnaflux Corp.) or equivalent. Readings should be taken adjacent to vibro etched serial number between the blade retention bolts on grip face. Inspect all spare grip assemblies before installation. Remove grip assemblies with readings below Rockwell 79 on the "B" scale or above conductivity of 39 on International Annealed Copper Standard.
This supersedes Amendment 39-953 (AD 70-06-01) issued by telegram dated February 27, 1970.
This amendment is effective March 13, 1970, and was effective for all recipients of the telegram dated March 4, 1970 which contained this amendment.