500 Hour Inspection Of Wing Flap Transmission Actuator Cable (Dukes Only) - Piper Navajo Chieftain PA-31-350 Service Manual

NAVAJO CHIEFTAIN SERVICE MANUAL
2.
Observe the clearance between the outer sheath and inner cable.
3.
Twist outer sheath in proper direction bringing clearance to 3/64 + 1/32 of an inch. It may
be necessary to loosen clamp on fuselage bulkhead in order to twist outer sheath.
4.
Holding outer sheath in this position, insert spline into flap motor, tighten nut finger tight
and wrench not over 1/16 turn from finger tight. Safety nut with .040 brass wire.
5.
Proceed with Steps 1 through 4 for other flex shaft if it has been disconnected.
6.
Tighten fuselage bulkhead clamp if loosened, reinstall access plates and make appropriate
logbook entry.
3-9a. 500 HOUR INSPECTION OF WING FLAP TRANSMISSION
ACTUATOR CABLE (Dukes
System Only. Aircraft S/N 31-5001 thru 31-7852171). Refer to Figure 3-2.
a.
Gain access to the flap motor and flexible shaft assemblies by removing the center floor panel in
the main cabin area and the right and left row of seats and floor panels aft of the main spar.
b.
Remove the aft access plate on the fairing located on the underside between the fuselage and wing.
c.
Remove the access plates at the aft side of the wheel well at wing stations 34.50, 44.50 and 54.00 and
on the underside of the wing at the trailing edge at wing stations 65.00, 82.75 and 92.50.
d.
Remove all Ty-Raps and support clamps along the entire length of both flexible shaft assemblies
and inspect the outer housing. If the housing is damaged, replace the flexible shaft assembly.
e.
Disconnect the flexible shafts and remove the flap motor. Using caution not to damage the flexible
shaft housing, route the flexible shafts outboard through the longitudinal beams. (Refer to Figure 3-2, Sketch
1).
NOTE
Do not disconnect flexible shaft from transmission at this time.
f.
Visually inspect the flexible shaft splined drive coupling and retaining pin for evidence of looseness
on the cable swage fitting (Refer to Figure 3-2, View A). If any looseness is apparent, replace the flexible shaft
assembly.
g.
Inspect the swaged fittings at both ends of the flexible shaft as follows:
1.
Expose the swaged portion of the inner cable at the motor end by twisting the outer housing
two turns clockwise. The swaged portion of the cable should have six (6), or eight (8), flats clearly visible and
free from deep scratches or wear marks.
2.
Using a micrometer, or dial caliper, measure the diameter of the swage for each of the flats
at the middle of the swaged portion of the cable. A total of three measurements should be taken for the six
flat cable ends, and four measurements should be taken for the eight flat cable ends. If any of the measurements
on the six flat cable ends exceed .235 inches, replace the drive shaft. If any of the measurements on the eight
flat cable ends exceed .247 inches, replace the drive shaft.
3.
Disconnect the drive shaft from the flap transmission. Using caution not to damage the shaft
housing, route inboard through the station 87.50 bulkhead (Refer to Figure 3-2, Sketch 2). Inspect the
swaged portion of the drive blade fitting end as described in steps "1" and "2" above.
4.
Inspect the drive blade dimension as shown in Figure 3-2, View B.
h.
Inspect the internal splines of the drive coupling for evidence of wear. If splines are distorted or
significantly worn, replace the drive shaft. The following method may be used to determine whether the
amount of spline wear is acceptable:
1.
Twist a piece of .032 safety wire around the swaged fitting at the motor end of the drive shaft to
form a pointer (Refer to Figure 3-2, Sketch 3). With one end of the flap motor armature shaft secured, engage
the opposite end into the flexible shaft spline.
Revised: 10/15/82
INSPECTION
1D19