Piper Arrow IV Turbo Maintenance Manual page 556

CHECKING PROPELLER BLADE TRACK.
Blade track is the ability of one blade tip to follow the other, while rotating, in almost the same plane.
Excessive difference in blade track - more than .0625 inch - may be an indication of bent blades or improper
propeller installation. Check blade track as follows:
1. With the engine shut down and blades vertical, secure to the aircraft a smooth board just under the tip
of the lower blade. Move the tip fore and aft through its full "blade-shake" travel, making small marks with a
pencil at each position. Then center the tip between these marks and scribe a line on the board for the full
width of the tip.
2. Carefully rotate propeller by hand to bring the opposite blade down. Center the tip and scribe a pencil
line as before and check that lines are not separated more than .0625 inch.
3. Propellers having excess blade track should be removed and inspected for bent blades, or for parts of
sheared O-ring, or foreign particles, which have lodged between hub and crankshaft mounting faces. Bent
blades will require repair and overhaul of assembly.
Effectivity
PA-28RT-201T
PIPER AIRCRAFT
PA-28RT-201 / 201T
MAINTENANCE MANUAL
Figure 61-3. Propeller Governor
3A24
61-10-05
Page 61-05
Revised- February 23, 1979