TB 1--1520--240--20--141
(e) Task 5-23.1.1, page 5-94.2.1, change paragraph 2.a. to read as follows -- " Using 10X
maginification, visually inspect tie bar plates for cracks. No cracks allowed."
(f) Task 5-23.1.1, page 5-94.2.1, add paragraph 3 as follows -- "3. Inspect the four slots in
the tie bar assembly as follows --
a 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.
NOTE
Recommend the probe not exceed 0.110 inch diameter
b If a suitable borescope and probe are not available, visually inspect each slot using a light
source.
c Reject tie bar assembly if any cracks are detected."
(3) TM 1-1520-252-10, Operator's Manual for Army MH-47E Helicopter -- Change maximum
transient rotor speed limit to 111 percent RPM.
(4) TM 1-1520-252-23, Aviation Unit and Aviation Intermediate Maintenance Manual, MH-47E
Helicopter --
(a) Task 1-99, page 3, change the retirement schedule hours for the forward and aft tie bar
assembly, P/N 114R2155-1, to be 4800 hours TSN.
(b) Add the following conditional inspection to Task 1-100.
3 The inspection frequency shall read -- "When rotor RPM exceeds 111 percent, but
does not exceed 115 percent RPM."
4 The inspection requirement shall read -- "Inspect the rotor head tie bar assemblies
per Task 5-31 at the next rotor head removal, but no later than completion of next
phased maintenance."
(c) Task 1-100, Reference 56 -- change "Speed" to read "RPM".
(d) Task 5-31, page 2, change paragraph 2.a. to read as follows: "Using 10X magnification,
visually inspect tie bar plates for cracks. No cracks allowed."
13. References.
a. DA PAM 738-751, 15 Mar 99.
b. TM 55-11520-240-23, Aviation Unit and Aviation Intermediate Maintenance Manual, CH-47D Heli-
copter.
c. TM 55-1520-240-10, Operator's Manual for Army CH-47D Helicopter.
d. TM 1-1520-252-23, Aviation Unit and Aviation Intermediate Maintenance Manual, MH-47E Helicop-
ter.
e. TM 1-1520-252-10, Operator's Manual for Army MH-47E Helicopter.
14. Recording and Reporting Requirements.
a.
Aircraft --
(1) TAMMS Reporting Compliance Suspense Date -- Upon entering requirements of this Techni-
cal Bulletin on DA Form 2408-13-1 for all effected aircraft, Commanders will forward a priority message, fax
or e-mail to Commander, AMCOM, ATTN: AMSAM--SF--A (SOF Compliance Officer), Redstone Arsenal, AL
35898-5000, in accordance with AR 95-1, no later than date specified in paragraph 3. Fax number is DSN
897--2111 or commercial (256) 313--2111. E-Mail address is "safeadm@redstone.army.mil". The report will
cite this message and TB number, date of entry in DA Form 2408-13-1, the aircraft mission design series and
serial numbers of aircraft in numerical order.
(2) Task/Inspection Reporting Suspense -- N/A.
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