76-08-06 BRANTLY: Amendment 39-2584. Applies to Model 305 helicopters certificated in all categories.
Compliance required as indicated after the effective date of this AD, unless already accomplished.
(a) Prior to further flight after January 18, 1968, remove Brantly torsion strap assemblies, P/N C0976-1 or P/N D2225-1, and replace with Brantly torsion strap assemblies, P/N D2225-3, in accordance with Brantly service kit, SK 305-67-5, dated December 15, 1967, Drawing D8001, Revision A, or later FAA approved revision, and Brantly Maintenance and Overhaul Instructions, revised December 18, 1967. Thereafter, replacement parts of the same numbers must be removed and replaced prior to accumulating 400 hours' time in service or sooner if Brantly clevis bearing, P/N ESJ 74837 or P/N 36NBC2048YZP, does not meet the conditions specified in paragraph (c) of this AD.
(b) Prior to further flight after January 18, 1968, remove Brantly main rotor hub clevis bearings, P/N ESJ 74837, and replace with unused Brantly serialized bearings, P/N ESJ 74837 or 36NBC2048YZP, in accordance with Brantly service kit, SK 305-67-5, dated December 15, 1967, Drawing D8001, Revision A, or later FAA approved revision, and Brantly Maintenance and Overhaul Instructions revised December 18, 1967. Bearings with the same part number must be used in the hub clevis. The clevis bearings must be hand packed with special lubricant and lubricated daily in accordance with Brantly Maintenance and Overhaul Instructions, revised December 18, 1967.
(c) Thereafter, at intervals not to exceed 50 hours' time in service from the last inspection, accomplish the following:
(1) Remove the clevis bearings from the hub assembly in accordance with the Brantly Maintenance and Overhaul Instructions, revised December 18, 1967, or in accordance with FAA approved equivalent procedures.
(2) Inspect each clevis bearing for deterioration or roughness as follows:
(i) Clean each bearing and inspect the grease residue for metallic particles. Maintain the bearing races indexing as removed from the clevis.
(ii) Load each bearing by hand and rotate the bearing a few degrees, back and forth, to detect bearing roughness.
(3) Remove the clevis bearings from further service if metallic particles were found in the grease residue or if the bearing has any roughness. The associated torsion strap assembly must be removed from further service also.
(4) If the clevis bearings are not rough and have no metallic particles in the residue, the clevis bearings may be installed but must be rotated 180 degrees from the index mark per Brantly Maintenance and Overhaul Instructions, revised December 18, 1967, or per FAA approved equivalent procedures.
(5) After rotation of the clevis bearing and after an additional 50 hours' time in service (100 hours' total time in service), the clevis bearing must be inspected, retired from service, and replaced with a clevis bearing serialized and manufactured in accordance with the type design. If replaced by a used Brantly serialized clevis bearing, the total accumulated service life must not exceed the service life limitations specified above.
(d) Compliance with applicable parts of AD 68-01-07 is equivalent to compliance with the same applicable parts of this AD.
(Brantly Helicopter Service Letter No. 103 dated February 10, 1976, pertains to use of the alternate clevis bearing.)
This supersedes Amendment 39-541 (33 F.R. 626), AD 68-01-07 that superseded Amendment 39-435 (32 F.R. 8708), AD 67-19-01.
This amendment becomes effective on receipt of the mailed amendment and is effective to all other persons on May 25, 1976.