TB 1--1520--237--20--243
d. Maintenance Trainers (Category A and B). Same as paragraph 1.a..
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 will ensure the Materiel Condition Tags of all items
in all condition codes listed in paragraph 7 are annotated to read: "TB 1-1520-237-20-243, Inspection of Main
Rotor Blade Pins, not complied with.
(1) Wholesale Stock. N/A
(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-
quired IAW paragraphs 8 and 9 on suspect materiel. Dispose of discrepant materiel IAW paragraph 10. Re-
port compliance with this TB IAW paragraph 14.c. NLT 19 February, 2002.
f. Components/Parts in Work (Depot Level and Others). N/A.
hours, but NLT 19 February, 2002 and report IAW para 14.a.(2) NLT 22 February 2002.
2002.
4.
Summary of Problem.
a. During the required maintenance action of Safety Of Flight Message UH-60-01-09 (TB
1-1520-237-20-233), Inspection and Correction, blade pins were discovered with a discrepant (off center)
staking of the pivot pin in the cam handle. AMCOM Engineering determined that this discrepancy may poten-
tially induce subsurface of surface micro cracks that could result in early failure of the pin or increase the prob-
ability of corrosion. No field rework to blend out these markings is under development or authorized because
the published procedures for blending could potentially remove/reduce the force holding the pivot pin in place.
All expandable pins with this discrepancy will be returned to the manufacturer for rework. Safety Of Flight
Message UH-60-01-12 mandated that the main rotor blade be lifted at every 10 Hour/14 Day PMS-1 inspec-
tion as part of the tension check. Engineering further analyzed this procedure and determined that the com-
plete pin tension check, which includes lifting the blade and partially removing the pin out far enough for the
top two expandable segments to be visible above the blade cuff, is not required at every 10 Hour/14 Day
PMS-1 inspection. The complete pin tension check, which includes lifting the blade and partially removing
the pin out far enough for the top two expandable segments to be visible above the blade cuff, will be accom-
plished at a new interval of 30 hours.
b. Manpower/downtime and funding impacts -- See paragraph 12.
c.
The purpose of this TB is to
(1) Accomplish a one time visual inspection of all expandable pins for manufacturing discrepan-
cy.
(2) Accomplish an initial complete pin tension check within the next 10 flight hours but NLT 19
February, 2002.
(3) Supercede the 10 hour/14 day PMS-1 inspection of the expandable pin imposed by para-
graphs 9.b. and 9.c., of TB 1-1520-237-20-236 (SOF Message UH-60-01-12), pin tension check during the
10 hour/14 day PMS-1 inspection.
(4) Add a new task to the 30 hour special inspection to accomplish the complete expandable pin
tension check.
5.
End Items to be inspected. All H-60 aircraft.
Assembly Components to be Inspected. N/A.
Parts to be Inspected. -
NOMENCLATURE
PART NUMBER
NSN
Pin, Expanding Grip
70103-08107-102
Pin, Expanding Grip
70103-08107-103
No NSN Assigned
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