(1) Ready aircraft for safe maintenance.
(2) Remove tail rotor servo/pitch change shaft assembly from tail gearbox per reference 13.
(3) Clean inside diameter of the output shaft using a low lint cloth dipped in approved cleaning fluid. Do not
allow the cleaning fluid to drip into the gearbox. Wipe shaft dry after cleaning.
(4) Protect the tail gearbox until the contractor inspection team conducts the ultrasonic inspection.
(5) Provide the logistical point of contact with the ultrasonic inspection results in accordance with paragraph
14.c. If the tail gearbox fails the inspection, remove the tail gearbox per reference 13. Replacement gearboxes will be
provided through the logistical point of contact on a one-for-one basis at no charge to the unit. DO NOT-REPEAT-DO
NOT turn in gearboxes which fail the ultrasonic inspection until authorized by the logistical point of contact. Other
support parts/hardware required to accomplish replacement of the tail rotor gearbox shall be provided by the unit. Tail
gearboxes which pass the inspection must be removed within 200 flight hours of the time the inspection is performed or
31 December 1995, whichever comes first.
(6) If applicable, install a tail gearbox with a P/N 70358-06620-101A or -102 output shaft.
(7) Ensure area is free of foreign objects.
(8) Install the tail rotor servo/pitch change shaft assembly into the tail gearbox per reference 13.
(9) Service tail gearbox per reference 13.
(10) Perform MOC/test flight as required.
b. Replacement of Tail Gearboxes. Scheduling for replacement of tail gearboxes containing -101 output shafts will
be controlled by the logistical point of contact. Schedules shall be based on the results of the onetime inspection
(reference paragraph 9.a), by operational/mission considerations and by logistical considerations. Units will be notified of
the date when the replacement is scheduled for their aircraft. Units will be required to have those aircraft scheduled for
tail gearbox removal at the designated site at the appropriate time. Once at the site, contractor teams will remove the
tail gearbox and replace it with a gearbox having a -101A or -102 output shaft installed. Replacement gearboxes will be
provided through the logistical point of contact on a one-for-one basis at no charge to the unit, unless the removed
gearbox is determined to be unserviceable for reasons other than the requirements of this TB. If the gearbox is already
turned in or a serviceable gearbox is not available for exchange, the unit will have to provide a funded requisition. Other
support parts/hardware required to accomplish replacement of the tail rotor gearbox shall be provided by the unit. The
unit shall be required to provide maintenance personnel, TI, maintenance test pilot, pilot and crew chief. Total time
required for the tail gearbox replacement, including both contractor team and unit activities is estimated to be 3 days.
10. Supply/Parts and Disposition.
a. Parts Required. Tail gearboxes required shall be provided through the logistical point of contact. Other support
parts/hardware required to accomplish replacement of the tail rotor gearbox shall be provided by the unit and should be
ordered through normal supply channels.
b. Requisitioning Instructions. N/A.
c. Bulk and Consumable Materials. N/A.
d. Disposition. Disposition of parts removed per this TB shall be provided by the logistical point of contact.
e. Disposition of Hazardous Material. N/A.
Special Tools, Jigs and Fixtures Required. N/A.
a. Category of Maintenance AVUM. Aircraft downtime for both the one-time ultrasonic inspection and for tail
gearbox replacement activities will be charged to AVUM Maintenance.
b. Estimated Time Required (Minus Maintenance Test Flight).