TB 1--1520--240--20--141
(a) Reduce the retirement life of the assembly to 4800 hours time since new (TSN).
(b) Replace all assemblies with more than 4800 hours TSN.
(c) Inspect all assemblies with less than 4800 hours TSN for cracks.
(2) Maximum Transient Rotor Speed Limit --
(a) Require rework of all 145ES008 rotor tachometers (all H-47D/F) and update software
(MH-47E) to indicate the max transient rotor speed of 111 percent RPM.
(b) Change the max transient rotor speed to be 111 percent RPM in the operaator's manuals.
(c) Establish a conditional inspection of the tie bar assembly if 111 percent rotor speed in ex-
ceeded.
5.
End Items to be inspected. All H--47 series aircraft.
Assembly Components to be Inspected. --
NOMENCLATURE
PART NUMBER
NATIONAL STOCK NUMBER
ROTOR HEAD ASSEMBLY
145R2003 -- ALL
ALL
ROTOR HEAD ASSEMBLY
145R2004 -- ALL
ALL
TIE BAR ASSEMBLY
114R2155-1
1615-00-740-6480
7.
Parts to be Inspected. --
NOMENCLATURE
PART NUMBER
NATIONAL STOCK NUMBER
TACHOMETER INDICATOR
145ES008-2
6680-01-127-2481
Inspection Procedures.
NOTE
Read and complete all paragraph 8 inspection procedures for each part
prior to proceeding to the correction procedures in paragraph 9.
a. Prior to the next flight, inspect the rotor head DA Form 2408-16 to determine the TSN of all tie bar
assemblies.
(1) If TSN is less than 4800 hours --
(a) Change the rotor head DA Form 2408-16 to indicate a new retirement life for the tie bar
assembly of 4800 hours TSN.
(b) Clear the red horizontal dash //--// entry required in accordance with paragraph 1a(1) of
this Technical Bulletin and enter a new red horizontal dash //--// status symbol with the following state-
ment: "Inspect all tie bar assemblies in accordance with paragraph 8b, CH-47-02-03 (TB
1-1520-240-20-141) at the next rotor head removal, but no later than the next phase inspection or 25
January 2004."
(2) If TSN is equal to or greater than 4800 hours, correct in accordance with paragraph 9a.
NOTE
Rotors heads received from supply after the message dating which have
zero hours time since overhaul (TSO) do not require inspection of the tie
bar assemblies in accordance with paragraph 8b.
b. At the next rotor head removal, but no later than the next phase inspection or 25 January 2004,
whichever occurs first, inspect the tie bar assemblies as follows --
(1) Remove tie bar assemblies in accordance with TM 55-1520-240-23, Task 5-23.1 (H-47D/F)
or TM 1-1520-252-23, Task 5-30 (MH-47E).
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