Piper Navajo PA-31 Service Manual page 153

PIPER NAVAJO SERVICE MANUAL
b. Fabricate a test weight in accordance with specifications in Table IV-I.
c.
With the elevators assembled and mounted in the jig, establish a horizontal reference mark which
aligns with the trailing edge of the elevator when held in a level position (chord line level). Ascertain that
the assembly rotates freely with no binding at knife edges.
d. Check the test weight arm location by measuring 8.28 inches forward from the hinge line and
identifying the tool hole at this point in the rib web center line. Early 40140 elevator assemblies require
the
drilling of a .191 hole at the above noted location if not previously located and drilled. Hang the
fabricated
master test weight in the above mentioned hole. (On PA-31-325 a master weight is hung on both sides
of
the elevator.)
e.
If the elevator is balanced (trailing edge aligns with reference mark) with just the master test
weight, the surface is at the minimum static limit per Table IV-I and is satisfactory.
f.
If the elevator is leading edge heavy, balance weight material must be removed to produce a
balanced condition with the master test weight in place. Remove trim weights, part number 43332 first,
if
installed; then remove material from the main balance weight. Remove material or trim weights evenly from
both sides.
g. If the elevator is trailing edge heavy with just the specified master test weight installed, then it
must be determined that the elevator does not exceed the maximum static limits per Table IV-I. Add
individual 0.1 pound test weights to master test weight until the elevator balances. If the number of 0.1
pound test weights does not exceed the maximum allowed per Table IV-I, the elevator is within the static
balance limits. If the number of 0.1 pound test weight added to the master test weight exceeds the
maximum allowable, the elevator balance exceeds the maximum, and trim weight must be added to the
surface balance weights, equally to each side, to produce a balanced condition. Ascertain that the number
of trim weights added does not exceed the maximum amount as stated in Table IV-I.
h. The installation of trim weights (P/N 43332-00) may be accomplished by the following
procedures:
1. Elevators (P/N 40140-00, -01, -28 and -29 on PA-31-310 aircraft, proceed as follows:
(a) If installed, remove elevator deicer boots by removing attaching screws.
(b) Remove the elevator tip by removing attaching screws.
(c) A trim weight attachment point is provided on the outboard rib at approximately one
inch aft of the leading edge. (Refer to Figure 4-17.) Weights are installed, not to
exceed two per anchor nut, with the proper length AN3 bolts. Should it be necessary
to install an additional third and fourth weight (per elevator), a second attachment
point is provided at approximately 2.75 inches aft of the rib leading edge. Distribute
the weights evenly between both elevators. (Should the second attachment anchor nut
not be provided, it may be installed per instructions given in Paragraph 4-93.)
(d)
Reinstall elevator tips with attaching screws.
(e) If removed, install deicer boots. Clean the surface of the skin in the area where the
boot attaches of all metal particles and dirt. Apply a sufficient amount of Sil-Glyde
lubricant to the area to be covered by the boot. Slide boot into place and secure
attaching screws.
Revised: 9/23/80
STRUCTURES
1G9