Piper Navajo PA-31 Service Manual page 110

SECTION IV . ..
STRUCTURES
4-1. DESCRIPTION. The fuselage is an all metal semi-monocoque structure with a maximum cross
sectional dimension of 63.0 inches in height and 46.0 inches in width. The overall length of the fuselage,
including tail cone, is 356.75 inches. The fuselage is constructed of bulkheads, stringers, stiffeners and
longitudinal beams, all of which the outer skin is riveted to. Windows include a two piece windshield and
five windows along each side. The four forward windows are double pane while the aft or triangular shaped
window is a single pane. A storm window is located in the forward lower section of the pilot's side window
and when the latch at the lower side is released, the window will swing in and forward. A 23 by 30 inch
emergency exit is an integral part of the second right window and isjettisonable when the release just aft of
the exit is pulled. The cabin extrance door is located on the left side of the fuselage just aft of the wing.
The door separates at the middle with the upper half swinging upward and the lower half swinging down to
provide cabin entrance steps.
Optional features available on the PA-31 and PA-31-325 Navajo include a pilot's door, cargo door and
nacelle storage lockers.
The pilot's door is located adjacent to the pilot's seat and permits rapid entrance to or exit from the
cockpit without the necessity of going the full length of the cabin.
The cargo door is located immediately aft of the cabin entrance door. This door swings up but only
after the cabin entrance door has been opened. This door permits rapid loading and storage of cargo and
also facilitates loading items normally too bulky to pass through the cabin entrance door.
The nacelle storage lockers affords additional storage space for luggage and sundry items. Each locker
provides an additional 13 cubic feet of storage space.
Each wing panel is an all metal, full cantilever semi-monocoque type construction with a removabl
fiberglas tip. Installed in each wing ahead of the main spar are two bladder type fuel cells. The main landing,
gear is enclosed in wheel wells built into the lower surface of each wing and is enclosed by doors when
retracted. Attached to each wing is the power plant, aileron and flap. The right aileron incorporates a trim
tab which is adjustable through a control in the cockpit. The full length I beam type main spars extend into
the fuselage and are jointed with high strength butt fittings in the center of the fuselage, making in effect a
continuous main spar. The main spar is also attached to the side of the fuselage as are the front and rear
spars.
The all metal empennage group is a full cantilever design consisting of a vertical stabilizer (fin), rudder,
right and left horizontal stabilizer and elevator, all with removable fiberglas tips. The rudder and right
elevator have a trim tab attached, that is controllable from the cockpit. Both the vertical and horizontal
stabilizers incorporate two channel main spars that run the full length of the stabilizer and attach to the aft
bulkhead assembly of the fuselage.
All components are completely zinc chromate primed and exterior surfaces are coated with acrylic
lacquer.
Reissued: 10/12/79
STRUCTURE
PIPER NAVAJO SERVICE MANUAL
1E14