Aircraft in Transit.
d. Maintenance Trainers (Category A, and B). Comply NLT 13 June 2001.
e. Component/Parts in Stock at All Levels (Depot Level and Others), including War Reserves. Upon
receipt of this TB, depot and materiel activity commanders at all levels will ensure the material condition tags
of all serviceable items listed in paragraph 7. are annotated to read: "TB 1-1520-237-20-233, main rotor blade
expandable pin inspection , not complied with."
(1) Wholesale Stock. Report receipt of this TB IAW 14.b.(1) NLT 13 June 2001. Upon Receipt
of this TB, depot and materiel activity commanders will ensure all items in condition codes //A//, //B//, //C//,
//D//, and //E//, listed in paragraphs 6 and 7, are placed in condition code //J// and tagged with a suspended
tag/label - materiel, DD form 1575/DD form 1575-1. Do not remove original condition tags. Report com-
(2) Retail Stock. Upon receipt of this TB, commanders and facility managers maintaining retail
stock at installation level and below shall contact the supported aviation unit to perform the procedures re-
Components/Parts in Work (Depot Level and Others). N/A.
. Task/Inspection Suspense Date. Complete the inspection IAW paragraphs 8and
to next flight
but NLT 13 June 2001and report IAW para 14.a.(2) NLT 15 June 2001.
Reporting Compliance Suspense Date
. Report compliance IAW para 14.a.(1) NLT
13 June 2001.
Summary of Problem.
a. Several main rotor blade expandable pins have been found with a potentially catastrophic crack in
the cam handle. The material investigation indicated that crack initiation was due to stress corrosion cracking.
These failures were due to non-conformance in the heat treatment process of the cam handle.
b. Manpower/downtime and funding impacts see para 12.
The purpose of this TB is to:
(1) Require a one time inspection of all main rotor blade expandable pins.
(2) Remove and replace all main rotor blade expandable pins manufactured by APEX manufac-
End Items to be inspected. All H-60 series aircraft.
Assembly Components to be Inspected..N/A
Parts to be Inspected.
Pin, Expanding Grip
Pin, Expanding Grip
(1) Conduct a records check, DA form 2408-16, to determine the serial number and component
hours of the main rotor blade pins.
(2) Confirm above data by performing visual inspection of all main rotor blade pins installed on