TB 1--1520--237-20--236
(4) If force is not at least 25 pounds, comply with requirements of paragraph 9.a..
Correction Procedures. .
a.
If force required to close handle is not at least 25 pounds, perform the following:
(1) Tighten nut. Rotate nut 1/6 (one sixth) turn and recheck closing force. Repeat until minumim
of 25 pounds closing force is obtained.
(2) Ensure that at least two threads extend beyond the nut after proper tension requirements are
met. If a minimum of two threads are not exposed, clean the expandable pin according to paragraph 1-4-6
of TM 1-1520-237-23-1 or paragraph 1.39.5 of TM 1-1520-250-23-1. After cleaning, repeat the tension test
according to paragraph 8.c.. Replace pin if criteria is not met. Perform this check for all installed pins. Upon
completion of this inspection, report compliance IAW provisions of paragraph 14.a.(2)..
(3) The red horizontal dash / / - / / will be cleared when the inspection procedures in paragraph
8. and, if
required, correction procedures in
paragraph 9. are completed.
b. Technical Manual, Preventive Maintenance Services, 10 hour/14 Day Inspection Checklist (TM
1-1520-237-PMS-1) will be changed as follows: In sequence number 6.18 (10 Hour/14Day) replace "check
main rotor blade expandable pins for security and make sure handles are firmly in place over lower nut." with
the following "check check main rotor blade expandable pins for correct tension and security. Ensure all ten-
sion is removed from the pin by lifting the blade during this check. Detailed procedures are contained in TM
1-1520-237-23-3, paragraph 5-3-9.1a and 5-3-9.1b. Upon completion of tension check, make sure handles
are firmly in place over lowewr nut."
c. Preventive Maintenance Services, 10 hour/14 Day Inspection Checklist (TM 1-1520-250-PMS-1)
will be changed as follows: In sequence number 6.18 (10 Hour/14Day) replace "check main rotor blade ex-
pandable pins for security and make sure handles are firmly in place over lower nut." with the following "check
check main rotor blade expandable pins for correct tension and security. Ensure all tension is removed from
the pin by lifting the blade during this check. Detailed procedures are contained in TM 1-1520-250-23-3, para-
graph 5.17.1.1a and 5.17.1.1b. Upon completion of tension check, make sure handles are firmly in place
over lowewr nut."
d. Technical Manual 1-1520-237-23-3, paragraph 5-3-9.1b(2) shall be changed to read: "Keeping the
spring force perpendicular to the long, riveted section of the handle, the force to close the handle shall be 25
pounds minumim."
e. Technical Manual 1-1520-237-23-3, paragraph 5-3-9.1b (3) (a) shall be changed to read: "If force
required to close handle is not at least 25 pounds, perform the following: Tighten nut. Rotate nut 1/6 (one
sixth) turn and recheck closing force. Repeat until minumim of 25 pounds closing force is obtained."
f. Technical Manual 1-1520-237-23-3, paragraph 5-3-9.1b (3) (b) shall be changed to delete: " Re-
peat tension check."
g. Technical Manual 1-1520-237-23-3, paragraph 5-3-9.1b (4) shall be changed to read: " Repeat
tension check. Keeping the spring force perpendicular to the long, riveted section of the handle, the force
required to close the handle shall be 25 pounds minumim, with two threads extending beyond the nut. Re-
place pin if criteria is not met."
h. Technical Manual 1-1520-237-23-3, paragraph 5-4-30.1.4.l(2) shall be changed to read: " Keep-
ing the spring force perpendicular to the long, riveted section of the handle, the force required to close the
handle shall be 25 pounds minumim."
i. Technical Manual 1-1520-237-23-3, paragraph 5-4-30.1.4.l(3) (a) shall be changed to read: "If
force required to close handle is not at least 25 pounds, perform the following: Tighten nut. Rotate nut 1/6
(one sixth) turn and recheck closing force. Repeat until minumim of 25 pounds closing force is obtained."
j. Technical Manual 1-1520-237-23-3, paragraph 5-4-30.1.4.l(3) (b) shall be changed to delete:
"
Repeat tension check."
k. Technical Manual 1-1520-237-23-3, paragraph 5-4-30.1.4.l(4) (b), shall be changed to read: " Re-
peat tension check. Keeping the spring force perpendicular to the long, riveted section of the handle, the
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