73-13-01 PIPER: Amendment 39-1665 as amended by Amendment 39-1936 is further amended by Amendment 39-1964. Applies to all Piper Model PA-34-200 "Seneca" airplanes, S/Ns 34-E4, 34-7250001 and up. Compliance required as indicated.
(a) Within the next 10 hours time in service after the effective date of this AD, unless already accomplished, determine the rudder trim tab "free play" as follows:
(1) Adjust rudder trim tab to neutral position with rudder trim wheel.
(2) Index tab to rudder. Use straight edge at trailing edge, making marks on rudder and tab that coincide.
(3) Hold light finger pressure against rudder tab in one direction and measure distance between marks.
(4) Reverse direction of finger pressure on rudder tab and measure distance between marks.
(5) "Free play" of the rudder tab is the sum of the distances measured in (3) and (4) above and should not exceed .125 inches.
(b) If rudder tab "free play" exceeds .125 inches, check the travel control arm assembly, P/N 96220-00 (Ref. Fig. 60, PA-34 parts catalog), for wear at the center bolt and at the bolt attaching the rudder trim rod assembly to the control arm. Replace the arm assembly and associated hardware if there is any noticeable wear or elongation of the bolt holes.
(c) Also check for end play in the rudder trim barrel, P/N 96596-00 (Ref. Fig. 34, PA-34 parts catalog). If end play exists, shim between the forward barrel mount support assembly and barrel. Reduce end play to the minimum amount attainable without causing excessive system friction.
Note: Shim (P/N 62833-18V) is a laminate made of 10 pieces of .002 inch brass shim stock, although it appears to be one solid piece. The proper thickness of shim material may be obtained by pealing off layers as required.
(d) Upon completion of any adjustments, re-check "free play" in accordance with the procedures of (a)(3), (a)(4), and (a)(5) to ascertain that travel is less than .125 inches.(e) Repeat the above inspection every 100 hours time in service after the initial inspection.
Piper Service Bulletin No. 390A pertains to this same subject.
When the airplane is modified with Piper Rudder Trim Mechanism Kit, Piper P/N 760800V, the repetitive inspections of (e) are no longer required.
Piper Service Letter No. 714 pertains to this same subject.
Amendment 39-1665 became effective June 18, 1973.
Amendment 39-1936 became effective August 30, 1974.
This Amendment 39-1964 becomes effective September 30, 1974.