TM 55-1520-240-23-4
5-6.1
INSPECT ROTARY-WING HEAD OIL TANKS FOR ALLOWABLE OIL
LEAKAGE
(Continued)
5-6.1
NOTE
Due to time required, it is best to
perform this inspection during a
scheduled flight of at least two hours.
HUB OIL TANK
1.
Service hub oil tank (1) (Task 1-55).
2.
Connect battery (Task 1-39).
3.
Have pilot perform a 30 minute ground run (TM
55-1520-240-10).
4.
Disconnect battery (Task 1-39).
5.
Install tiedown line (2) on one forward blade (3)
(Task 1-26).
NOTE
Blades must be in proper position to
get a correct reading of oil level.
6.
Using tiedown line (2), turn blades (3) so that
one is positioned at a 90º angle to left or right
side of helicopter.
7.
Check oil level in sight gage (4) next to blade (3)
that is at 90º angle. If oil is at bottom of gage,
leakage is excessive.
8.
If leakage is excessive, horizontal hinge pin
seals are defective. Replace seals (Tasks 5-42
and 5-43).
PITCH BEARING OIL TANK
9.
Service pitch bearing oil tank (5) (Task 1-56).
10.
Connect battery (Task 1-39).
11.
Have pilot perform a 30 minute ground run (TM
55-1520-240-10).
12.
Disconnect battery (Task 1-39).
13.
Install tiedown line (2) on one forward blade (3)
(Task 1-26).
NOTE
Blades must be in proper position to
get a correct reading of oil level.
14.
Using tiedown line (2), turn blades (3) so that
blade of tank (5) to be checked is over drive shaft
tunnel (6).
15.
Check oil level in sight gage (7) on each side of
oil tank (5) of blade (3) over tunnel (6). If average
level at two gages is at bottom of sight gage,
leakage is excessive.
16.
If leakage is excessive, pitch-varying housing oil
seals are defective. Replace seals (Tasks 5-24
and 5-25).
5-37
