TB 1-1520-240-20-150
(7) Unlock Rotor Heads; H--47D/F per TM 55--1520--240--23; Task 5--99, Install Pitch Links (re-
move Pitch Link Lockpins) and Task 11--29, Remove Servocylinder Safety Blocks. MH--47E per TM
1--1520--252--23; Task 5--148, Install Pitch Links (remove Pitch Link Lockpins) and Task 11--34, Remove Ser-
vocylinder Safety Blocks.
CAUTION
For the purpose of this message only, a test flight to track the rotor
blades is not required as long as no adjustments were made to the
Pitch Links and the Pitch Links are installed back in their original
location.
b. Initial and recurring 50 hour lubrication/purge and initial and 50 hour recurring grease sample of all
H--47D/F Forward and Aft Swashplate Bearings.
(1) Using a soft, clean, lint--free cloth, dampened with cleaning solvent (MIL--PRF--680), clean
the inner ring assembly and outer ring assembly at the upper seal. Wipe dirt and grease from lubrication fitting.
Ensure all surface grit, sand, and other foreign material is removed, ensuring an uncontaminated grease sam-
ple.
NOTE
Mobil 28 grease is recommended if available.
CAUTION
Pumping grease into swashplate without turning rotating ring can
result in bearing damage.
NOTE
If you cannot pump grease and rotate the swashplate at the same time,
rotate swashplate in 12 equal steps, 30 degrees each step. Pump in
grease between steps.
(2) Army Oil Analysis Program (AOAP) grease sample procedure.
(a) Have helper rotate ring by pulling blades around with tie down line. As ring rotates, pump
grease into fitting. Rotate the ring through at least one full turn (360 degrees) to ensure thorough purging
of the bearing. Use a hand lubricating grease gun with a flexible hose. Pump until clean grease appears
all the way around the line between the stationary upper seal and rotating upper seal. Ensure all the old
grease is purged from the assembly and is immediately collected. Use a tongue depressor to fill a three
ounce plastic sampling bottle at least half full and reserve the remaining purged grease for use in sub-
(b) Once the AOAP sample is taken, the bottle label should be filled out as completely as
possible to avoid confusion with other grease samples.
(c) Submit the AOAP grease sample to the AOAP laboratory with a complete DD Form 2026.
(d) Maintain the DA Form 2408--20 on each swashplate in accordance with DA PAM
738--751.
(3) Use the additional grease sample and feel for metal chips in grease. If there are chips, the
swashplate shall be considered unserviceable and disposition in accordance with paragraph 11d of this mes-
sage.
(4) The Swashplate Bearing will now be required to be lubricated and a grease sample taken ev-
ery 50 flight hours.
c. Using a flashlight or other suitable light source, visually inspect with a mirror or flexible borescope
the area between the underside of the rotating ring and stationary ring for any slinging or clumping or grease/
debris (i.e. seal, bearing cage, seal spring, wire, or other material). A thin even bead of grease around the
sealing area is considered normal. This inspection will now be required on the Preventive Maintenance Daily
(PMD).
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