87-09-02 R2: Drive Hub Assembly

87-09-02 R2 BELL HELICOPTER TEXTRON, INC. (BHTI): Amendment 39-6399. Final copy of Priority Letter AD, as revised. Docket No. 87-ASW-17. Applicability: All BHTI Model 222 helicopters, certificated in any category, with drive hub assembly, part number (P/N) 222-010-417-009, installed. Compliance with paragraphs (a) and (b) is required immediately upon receipt of this AD, unless already accomplished. To prevent possible failure of the drive hub studs which could result in loss of flight control and subsequent loss of the helicopter, accomplish the following: (a) Remove nuts and washers from the studs which attach spline plate, P/N 222-310- 418-105/-107, to the drive hub assembly, P/N 222-010-417-009. (b) Visually inspect washers, P/N AN960-416, and mating surface on the spline plate, P/N 222-310-418-105/-107, for any signs of fretting, cracking, or wear. (1) If any fretting or wear is found, replace spline plate, P/N 222-310-418- 105/-107, and drivehub assembly, P/N 222-010-417-009. (2) If no fretting or wear is found, install new nuts, P/N MS21042L4, and washers, P/N AN960-416, and torque nuts to 100-pounds plus friction (tare) torque. (c) After completing requirements of paragraphs (a) and (b) and at intervals not to exceed 50 hours' time in service thereafter; apply 50 inch-pounds of torque to the spline plate, P/N 222-310-418-105/-107, retaining nuts. (1) If the nuts do not move, the nut torque is sufficient. (2) If one or more nuts move prior to reaching 50 inch-pounds, replace spline plate, P/N 222-310-418-105/-107, and drive hub assembly, P/N 222-010-417-009. (Maintenance manual 222-MM-1, Section 65-20-00, paragraphs 65-33 and 65-35 applies to this.) (d) An alternate method of compliance or adjustment of the compliance time, which provides an equivalent level of safety, may be used when approved by the Manager, Rotorcraft Certification Office, Rotorcraft Directorate, Aircraft Certification Office, FAA, Southwest Region, Fort Worth, Texas. (e) In accordance with FAR Sections 21.197 and 21.199, flight is permitted to a base where inspections required by this AD may be accomplished. This amendment (39-6399, AD 87-09-02 R2) becomes effective on December 22, 1989, as to all persons except those persons to whom it was made immediately effective by Priority Letter AD's 87-09-02, issued April 24, 1987, and 87-09-02 R1, issued April 28, 1987, which contained this amendment.