AD 78-18-02

78-18-02 MCDONNELL DOUGLAS: Amendment 39-3289. Applies to Model DC-3 Series, DC-3A Series, DC-3C Series, DC-3D, Super DC-3 and R4D Series certificated in all categories, including all military models.

Compliance required as indicated.

To minimize the possibility of a jammed elevator control system, due to cable interference accomplish the following:

(a) Within the next 25 hours time in service after the effective date of this AD; unless already accomplished within the last 60 days:

NOTE: Determine that the elevator control system is properly rigged prior to accomplishment of the inspections required by this AD.

(1) Visually inspect the right and left elevator upper cables and cable fittings for possible interference with the bulkhead frame and channel located just aft of the control column assembly at fuselage station (F.S.) 63 on the DC-3 Series and at F.S. 24 on the Super DC-3. The elevator cable and/or cable fitting must have 3/32 inch minimum clearance relative to the bottom of the cutout hole and both legs of the channel, throughout full cable travel. Pay particular attention to clearance when the elevator horn of the control column is rotated to the lowest point of its movement arc.

NOTE: The channel is attached to aft side of bulkhead frame and the upper elevator cables are attached to extreme bottom of control column elevator horn, located forward of the bulkhead frame. Inspection may be accomplished after removal of external access plates on bottom of fuselage, forward and aft of F.S. 63 on DC-3 Series and F.S. 24 on the Super DC-3.

(2) If existing clearance is less than required by paragraph (a)(1), trim out the cable cutout hole in the bulkhead frame and both legs of the channel to provide a nominal clearance of 1/8 + 1/32 inches using a minimum 1/4 inch corner radius. Break and smooth all edges.

(b) Special flight permits may be issued in accordance with FAR's 21.197 and 21.199 to operate airplanes to abase for accomplishment of the inspection required by paragraph (a)(1).

(c) Equivalent modifications may be used when approved by the Chief, Aircraft Engineering Division, FAA Western Region.

This amendment becomes effective September 6, 1978.