Adjustment Of Low Pitch Blade Angle And Stop; Typical Nicks And Removal Method Diagrams - Piper Navajo Chieftain PA-31-350 Service Manual

278
NAVAJO CHIEFIAIN SERVICE MANUAL
EXAGGERATED VIEW OF
NICKS IN LEADING EDGE
EXAGGERATED VIEW
NICKS IN FACE OF BL
SECTION
NICK IN F
REMOVE
CROCUS
MENDED.
OF
ADE
RECOMMENDED METHOD FOR
REMOVING NICKS BY RIFFLE
FILE AND CROCUS CLOTH.
BLEND DEEPEST PORTION OF
NICK INTO LEADING EDGE
ALIGNMENT WITH SMOOTH
CURVES.
A-A
FACE OF BLADE
BY FILE AND
CLOTH AS RECOM-
U
Figure 8-4. Typical Nicks and Removal Method
g.
at the aft
h.
Test for leakage by using a soap solution or equivalent and applying it around the valve stop and
end of the tube. Internal leakage will show up as flow of air through the tube.
Install spinner cap and cowling.
8-21. ADJUSTMENT OF LOW PITCH BLADE ANGLE AND STOP.
a.
The propeller comes from the factory with the low pitch stop adjusted for proper blade angle. If.
however, this adjustment has been disturbed, the following procedure is given for obtaining blade angle:
1.
The blade angle (Refer to Table VIII-I) is determined by placing a propeller protractor on
the face side of the propeller at the 30 inch station as measured from the hub centerline. The blade must be
horizontal.
2. The low pitch stop adjustment is made by a screw in the nose of the propeller cylinder.
Rotating the screw clockwise increases the low pitch and reduces the static RPM by about 100 RPM for
each half turn; or vice versa.
CAUTION
Before adjusting the low stop screw, the air pressure should be
dropped to zero. Unless this is done, it is possible to unscrew the
low stop far enough to disengage the threads, allowing the air
pressure to blow the stop screw out with great force. There should
be at lease four of the twenty threads of the stop screw engaged.
Reissued: 9/23/80
POWER PLANT
2H14