TB 1--1520--240--20--141
NOTE
The procedure in paragraph 8b(2) is in accordance with Change Number
47 for the H-47D/F, and Change Number 17 for the MH-47E.
(2) Inspect tie bar assemblies in accordance with TM 55-1520-240-23, Task 5--23.1.1 (H-47D/F),
or TM 1-1520-252-23, Task 5-31 (MH-47E).
(3) Using 10X magnification, visually inspect tie bar plates for cracks. No cracks allowed.
(4) Inspect the four tie bar slots as follows -- using a borescope with a rigid right angle probe, insert
the borescope probe in each slot. Examine the slots for cracks along the full depth and span. Recommend
the probe not exceed 0.110 inch diameter. If a suitable borescope and probe are not available, visually inspect
each slot using a light source.
(5) If a tie bar assembly fails an inspection in accordance with paragraph 8b, correct in accor-
dance with paragraph 9a.
(6) If no damage is found --
(a) Reinstall the rotary wing head tie bar assemblies in accordance with TM 55-1520-240-23,
Task 5-23.2 (H-47D/F) or TM 1-1520-252-23, Task 5-32 (MH-47E).
(b) Clear the red horizontal dash //--// entry.
c. Prior to 25 February 2002, inspect the aircraft rotor tachometer --
(1) For the 145ES008-2 rotor tachometer (H-47D/F) -- correct in accordance with paragraph 9b.
NOTE
Currently all 145ES008-2 rotor tachometers are marked to indicate the
maximum transient rotor speed at 115 percent. Eventually new rotor
tachometers will be available that will be marked at 111 percent.
(2) For the multi--function display (MFD) software (MH-47E) -- correct in accordance with para-
graph 9c.
NOTE
Ensure that replacement tie bar assemblies are inspected and in com-
pliance with this Safety of Flight (SOF) prior to installation.
a. If the TSN is equal to or more than 4800 hours, or if a tie bar assembly fails an inspection in accor-
dance with paragraph 8b --
(1) Change the rotor head DA Form 2408-16 to indicate a new retirement life for tie bar assembly
of 4800 hours TSN.
(2) Clear the red horizontal dash //--// entry and enter a red //X// status symbol with the following
statement: "Replace the rotary wing head tie bar assemblies in accordance with CH-47-02-03 (TB
1-1520-240-20-141)."
(3) Submit a category I deficiency report on any tie bar assembly that has failed the inspection
required in accordance with paragraph 8b due to cracks.
(4) If TSN is equal to or more than 4800 hours, contact the Technical point of contact in paragraph
(5) Reinstall the rotary wing head tie bar assemblies in accordance with TM 55-1520-240-23,
Task 5-23.2 (all H-47D/F) or TM 1-1520-252-23, Task 5-32 (MH-47E).
(6) Clear the red //X// entry.
b. For all H-47D and H-47F Helicopters -- Rework all rotor tachometers as follows --
(1) Remove rotor tachometers from the aircraft in accordance with TM 55-1520-240-23, Task
8-88.
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