Piper Comanche PA-24 Service Manual page 70

Threaded Fastener Installation.
2-7b.
A. Fastener Lengths
Fastener lengths must be long enough to prevent bearing loads on threads. In addition, the fastener
or screw must extend through the nut.
The specified fastener grip length can be varied by one size (longer or shorter) to meet requirements
stated above.
B. Washer Usage
Add a maximum of two NAS1149 washers (of the correct diameter, material and finish that
matches the fastener being installed) under fastener heads or nuts to correct for variations in
material thickness within the tolerances permitted. Where needed, use a maximum of two standard
filler washers (spacers) under the nut to adjust for fastener length or alignment of cotter key hole.
Where nutplates are used, adjust for protruding head fastener length by using up to a maximum of
two standard filler washers under the fastener head.
C. Self-locking Fasteners
The use of self-locking nuts, fasteners and screws, including fasteners with non-metallic inserts is
subject to the following limitations:
(1) Fasteners incorporating self-locking devices must not be reused if they can be run up using less
than the required minimum torque values specified or as shown in Table II-IIA. They may be
reused, if hand tools are required to run them up, providing there is no obvious damage to the
self-locking device prior to installation.
(2) Fasteners 5/16 inch diameter and over with cotter pin holes may be used with self-locking
nuts.
(3) Self-locking nuts must not be used at joints which subject either the nut or the fastener to
rotation.
(4) Self-locking fasteners shall never be tapped or rethreaded. Nuts, fasteners and screws with
damaged threads or rough ends shall not be used, or rethreaded.
D. Torque
See Torque Requirements, above.
2-8. Handhold and Walkways.
CAUTION: AVOID DAMAGE TO THE WINGS BY STEPPING ONLY ON THE WALKWAY.
A fixed handhold is located on the right side of the fuselage, above the rear window. Walkways of four
parts Devoe non-skid compound and one part black enamel are painted on the right wing and flap.
2-9. Ground Handling.
Introduction to Ground Handling.
2-10.
Ground handling covers all essential information governing the handling of the airplane while on the
ground. This includes jacking, weighing, leveling, mooring, parking, towing and taxiing. When the
airplane is handled in the manner described in the following paragraphs, damage to the airplane and its
equipment will be prevented.
II - HANDLING AND SERVICING
PIPER COMANCHE SERVICE MANUAL
1B22B
(PIR-PPS20015-1, Rev. W.)
04/01/09