TB 1--1520--237--20--230
e. Maintenance Trainers (Category A, and B) -- Same as para 1a.
f. Wholesale and Retail Stock -- Upon receipt of this message, Depot and Material Activity Command-
ers will ensure the material condition tags of all items in all condition codes listed in paragraphs 6 are anno-
tated to read: "TB 1--1520--237--20--230 Inspection of Main Rotor Spindle Lugs, Not Complied with".
(2) Retail Stock -- Upon receipt of this message, Commanders and Facility managers maintain-
ing retail stock at installation level and below shall contact the supported aviation unit to perform the proce-
dures required IAW paragraph 8 and 9 on suspect material. Dispose of discrepant material IAW paragraph
g. Components/Parts in Work (Depot Level and Others) -- Depot and other Maintenance activity Com-
manders will ensure items listed in paragraph 6 are not issued until they are in compliance with this message.
2.
Task/Inspection Suspense Date. Complete the paragraph 8 Inspection within the next 100 flight hours
3.
Reporting Compliance Suspense Date. Report compliance IAW paragraph 14a NLT 9
March 2001.
4.Summary of the Problem.
a. History / Background --
(1) TB 1--1520--237--20--221 was published to inspect all spindles for broken lugs, and to imple-
ment a revised 10 hour / 14 day recurring visual inspection of the Spindle Lugs, and the Main Rotor Blade
Expandable Pins. Since the SOF was issued, an Ultrasound Non--Destructive Inspection (NDI) technique
has been developed to find small cracks in the Spindle Lug in areas that are not normally inspectable without
removal of the bushing. In addition, questions arose during the initial investigation concerning the fractured
lug whether a non--conforming pin could have been a factor in the process. The investigation into the fracture
and crack growth rate of the Spindle Lug continues.
c.
The purpose of this TB is to --
(1) Implement an initial and recurring Ultrasound NDI of the Main Rotor Blade Attachment Lugs.
(2) Conduct a one--time inspection of all Main Rotor Blade Expandable Pins for items not con-
forming to configuration.
(3) Revise the 10 hour / 14 day inspections for all the Main Rotor Blade Attachment Lugs and
the Expandable Pins.
5.End Items to be inspected. All H--60 series aircraft.
6.Assembly Components to be Inspected.
NOMENCLATURE
PART NUMBER
NSN
Spindle Assembly
ALL PART NUMBERS
ALL NSN NUMBERS
Spindle Liner Assembly
ALL PART NUMBERS
ALL NSN NUMBERS
7.Parts to be Inspected. N/A
NOMENCLATURE
PART NUMBER
NSN
Main Rotor Expandable Pin
70103--08107--102
5315--01--329--0707
Main Rotor Expandable Pin
70103--08107--103
NO NSN
2