Elongation Limits - Piper APACHE PA-23-235 Service Manual

(11) FLAP TORQUE TUBE 100 HOUR INSPECTION.
least 2500 hours total time-in-service and have not installed a steel flap torque tube (P/N
17634-002, 104622-002, or 104622-004);
whichever comes first, inspect the flap torque tube for wear, distortion, and corrosion as
follows:
NOTE: Installation of a steel flap torque tube P/N 17634-002, 104622-002, or 104622-004
relieves this repetitive inspection requirement.
(a) Remove the flap torque tube assembly per paragraph 5-50.
(b) After the flap torque tube has been removed from the aircraft and prior to removing the
end plugs, examine the area of the torque tube that comes in contact with the torque tube
bearing blocks for wear and distortion. If wear or distortion is noted on the tube and the
depth exceeds .005 inches, replace the torque tube per paragraph 4-12B.
(c) Inspect the attachment bolt holes
(for the flap horn and the flap
bellcrank) in the flap torque tube
for cracks originating out of each
hole using a Fluorescent Penetrant
procedure per the latest revision of
AC 43.13-1. Also, inspect the
subject holes for elongation.
Elongation up to .050 inch (see
Figure 3-9) is acceptable provided
that when the horn or bellcrank is
mounted on the tube with the
attachment bolts (without nuts)
installed, there is no relative motion
between the horn or bellcrank and
the torque tube with a light load
applied in a radial direction
simulating a flap air load. Replace the torque tube per paragraph 4-12B, if cracks are
noted in the subject holes or elongation exceeds limits.
(d) Remove the end plugs and inspect and remove any corrosion present on the inside
diameter of the torque tube, specifically in the area that contacts the wooden end plug
(P/N 17631-000). See the latest revision of AC 43.13-1 for corrosion removal and
corrosion protection processes. If severe cleaning is required, including the mechanical
removal of all the corrosion, the resultant wall thickness must be measured and cannot be
less than .063 inches. Replace the torque tube per paragraph 4-12B, if corrosion cannot be
repaired, or if remaining wall thickness does not meet minimum requirements.
(e) Inspect the wooden end plugs (P/N 17631-000) for deterioration and close fit with the
inside diameter of the torque tube. The maximum acceptable clearance between the inside
diameter of the torque tube and the outside diameter of the plug is .015 inches. The plugs
should be treated with a wood preservative product such as "tung oil" prior to reinstalling
in the torque tube. If replacement of the plugs is required, order new plug P/N 17631-002
which is manufactured from Acetal (Delrin) rod.
(f) If the torque tube meets the inspection requirements, above, it can be reinstalled per
paragraph 5-51.
III - Inspection
PIPER AZTEC SERVICE MANUAL
6E20
For airplanes which have accumulated at
each 100 hour time-in-service or annually,
TORQUE TUBE
.249 / .251 IN.
ACCEPTABLE LIMITS FOR OBLONG HOLE
(ANGLE TO CENTER LINE IS NOT CRITICAL)
Figure 3-9. Elongation Limits
.30 IN. MAX.
07/15/06