TB 1-1520-237-20-162
1995 (Paragraph 9.a).
(3) Remove tail gearboxes containing -101 output shafts by 31 December 1995 (Paragraph 9.b).
5.
End Items to be Inspected. All H-60 Black Hawk Aircraft, except MH-60K. Aircraft serial numbers 94-26555 and
subsequent will be inspected/corrected by contractor during production and therefore records for aircraft serial numbers
94-26555 and subsequent will not require identification of this action.
6.
Assembly Components to be Inspected.
NOMENCLATURE
PART NO.
NSN
TAIL GEARBOX
70358-06600-041
TAIL GEARBOX
70358-06600-042
TAIL GEARBOX
70358-06600-043
TAIL GEARBOX
70358-06600-044
TAIL GEARBOX
70358-06600-046
7.
Parts to be Inspected.
NOMENCLATURE
PART NO.
NSN
TAIL GEARBOX OUTPUT
70358-06620-101
3020-01-090-3423
SHAFT
8.
Inspection Procedures.
a. Review the tail gearbox component historical record (DA Form 2408-16) to determine the part number and serial
number of the tail gearbox output shaft.
b. If the tail gearbox output shaft is P/N 70358-06620-102 or P/N 70358-06620-101 A, the inspection is complete.
c. Some P/N 70358-06620-101 output shafts have been reworked but only the serial number has been updated to
identify the action. If the final character of the P/N 70358-06620-101 tail gearbox output shaft serial number is an "A",
e.g., XXXX-XXXXXA, the shaft has already been reworked and the inspection is complete.
d. If the tail gearbox output shaft is P/N 70358-06620-101, and the shaft serial number does not end with an "A",
contact the logistical point of contact (paragraph 16.b) by fax or E-Mail to schedule performance of a one-time ultrasonic
inspection and replacement of the tail gearbox. Replacement tail gearboxes will be provided at no cost to the unit
provided the currently installed tail gearbox is removed per this TB. Other support parts/hardware required to accomplish
tail rotor gearbox replacement shall be provided by the unit. If the removed gearbox is determined to be unserviceable
for reasons other than the requirements of this TB, the unit will be required to provide a funded requisition for the
replacement gearbox.
9.
Correction Procedures.
a. One-Time Ultrasonic Inspection. Scheduling of the inspection will be controlled by the logistical point of contact.
Units will be notified of the date when the inspection is scheduled for their aircraft. Inspections will be conducted by
contractor teams. Units will be required to prepare the aircraft/tail gearbox for the inspection and return the aircraft to
serviceable condition, including maintenance test flight. The aircraft must be prepared for ultrasonic inspection in
continuing quantities to allow the inspector to work on a continuous 3 aircraft per hour schedule. A high level of
emphasis is required to schedule and prepare aircraft to allow all gearboxes to receive ultrasonic inspection by the
suspense date. The unit shall be required to provide mechanics, technical inspector (TI), maintenance test pilot, pilot
and crew chief. The total time to prepare the aircraft, conduct the inspection and return the aircraft to an airworthy status
is estimated to be 8 hours. The basic procedure for preparing the aircraft for ultrasonic inspection is as follows:
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