Piper Navajo PA-31 Service Manual page 212

PIPER NAVAJO SERVICE MANUAL
5-26. INSTALLATION OF ELEVATOR BELLCRANK ASSEMBLY. (Refer to Figure 5-5.)
a.
Position the bellcrank (14), install pivot bolt (24) and torque to 60-85 in. lbs.
b.
Attach the forward end of the control rod (15) to the bellcrank (14) and secure.
c.
The aft end of the control rod (15) and balance spring (16) are to be connected during rigging
and adjustment.
NOTE
Apply corrosion retardant compound to the balance spring (16)
with the spring in the extended position to insure full coverage of all
coils. Refer to lubrication chart.
d.
Connect the control cables (10 and 11) to the bellcrank (14). Tighten bolts (22) so that the cable
ends (21) may turn freely on the bellcrank and safety.
e.
Check cable tension per Table V-I. Check rigging and adjustment as given in Paragraph 5-27
f.
Install access plates, tail cone and seat.
5-27. RIGGING AND ADJUSTMENT
OF ELEVATOR CONTROLS. (Refer to Figure 5-5 ) ppss00-46
a.
Ascertain that the left pilot's seat, the floor panel to the left of the control pedestal, an access
plate on the side of the fuselage under the horizontal stabilizer and tail cone are all removed.
b.
Put the elevator in neutral position by placing a modified straightedge, as shown in Figure 5-6,
against the underside of the horizontal stabilizer, next to and inboard of the row of rivets at station 19.0
with the aft end of the tool even with the trailing edge of the elevator. (This tool may be fabricated from
dimensions given in Figure 5-28.)
d.
With the elevator bellcrank neutral, adjust the turnbuckles (3) at fuselage station 110.5 to obtain
cable tension as given in Table V-I and to allow the control wheel to neutralize fore and aft. The neutral
position of the control wheel for the PA-31 is 8.25. ± .25 inches and 9.00 ± .25 inches for the PA-31-325 as
measured from the instrument panel along the underside of the control column to the wheel. On PA-31-325
only, remove or place a block under the bobweight prior to checking cable tension.
e.
To set the proper tension of the elevator balance spring (16), connect a spring scale to the aft end of
the spring and pull rearward until 30 lbs. + I lb. tension is obtained for PA-31-300 or PA-31-310 models or
37 lbs. ±
lb. for PA-31-325 models with the elevator in the neutral position. At this point observe which
hole in the link (17) is in line with the hook at the end of the spring and connect the spring into this hole in the
link. If proper tension cannot be obtained by using existing holes, four additional holes may be drilled per the
latest revision of Service Bulletin 549.
NOTE
If provisions are provided for safety wiring the nut and screw on the
elevator hinge assembly, safety wire per MS33540 as shown in
Figure 5-7a. The lock wire should always be installed and twisted so
that the loop around the head stays down and does not tend to come
up over the bolt head and leave a slack loop.
Revised: 5/3/84
SURFACE CONTROL
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