Inspection Procedures -

TB 1-1520-240-20-91

Parts to be Inspected -

NOMENCLATURE

PART NUMBER

NATIONAL STOCK NUMBER

Nut, Self-locking Barrel

NAS577B20A

Inspection Procedures -

a. Prepare the aircraft for safe ground maintenance.

b. Visually inspect the four (4) NAS577B20A barrel nuts (see paragraph 13 below, reference c.,

Task 6-51, Item 13.1, or reference d, Task 6-60, item 15) that attach the forward transmission to the airframe. The nuts

fasten to the bottom of the mounting bolts (item 14 or item 17).

c. Inspect each barrel nut to determine the manufacturer. Use a flashlight and mirror to improve readability.

d. If the exposed barrel nut carrier is impression stamped with HAP or the CAGE code 66861, the nut was

manufactured by Hartford Aircraft Products, Inc., is suspect, and must be remove from service. Proceed to paragraph 9

below for corrective action.

e. If the exposed barrel nut carrier is marked in any other way, or has no markings, the nut is acceptable and no

further action is required. Record and report compliance with this TB in accordance with paragraph 14 below.

Correction Procedures -

a. Replace NAS577B20A barrel nuts exhibiting an impression stamp of HAP or CAGE code 66861 with any other

manufacturers nut prior to further flight.

b. Whenever a barrel nut is installed, the bolt must be torque in accordance with paragraph 13 below, reference c.,

Task 6-51, paragraph 9 or reference d., Task 6-60, paragraph 12. Also, a one time retorque after 25 flight hours is

required.

c. Any suspect barrel nut removed from an aircraft or found in supply shall be disposed of by mutilation/demilitarized

to prevent resale, reissue, or use by any other MDS aircraft systems (i.e., UH-60, AH-64, etc.).

10. Supply/Parts and Disposition -

a. Parts Required - Items cited in paragraph 7 above may be required to replace defective items.

b. Requisitioning Instructions - Requisition replacement parts through normal supply channels using normal supply

procedures. All requisitions shall use project code 'XCS" per this TB.

NOTE

Project code 'XCS" is required to track and establish a data base of stock fund expenditures incurred by

the field as a result of this TB.

c. Bulk and Consumable Materials - N/A.

d. Disposition - After mutilation or demilitarization IAW published procedures, dispose of removed components/parts

IAW normal supply procedures. A QDR is not required.

e. Disposition of Hazardous Materiel - N/A.

11. Special Tools, Jigs and Fixtures Required - N/A.

12. Application -

a. Category of Maintenance - AVUM. Aircraft downtime will be charged to AVUM.

b. Estimated Time Required -

(1) Total of one (1) man-hour using one (1) person.