AD 61-22-03 ACTIVE

61-22-03 CANADAIR: Amdt. 356 Part 507 Federal Register November 1, 1961. Applies to all CL-44D4 aircraft.

Compliance required as indicated.

The following measures are required pending the development and installation of Canadian Department of Transport and FAA approved modification to the outer elevator hinge fittings to prevent elevator flutter during flight.

Within the next 25 hours' time in service after the effective date of this AD, and every 25 hours' time in service thereafter, apply an upload of approximately 110 lbs. on elevator spar at Station 299 and check for fore and aft movement at upper and lower hinge bracket attachments.

(a) If movement exceeds .010 inches at the upper and lower hinge bracket attachment points, the fittings, P/N 28-A24498 A and B and P/N 28-A24670 must be reworked as stated in (1) or (2):

(1) Open up the .375-inch diameter holes to .4375 plus or minus .0005-inch diameter. Replace existing bolt, P/N 28-A24367 with an NAS 464-7-22 bolt or equivalent; AN 320-7 nut or equivalent; (use washers under nut to line up cotter pin hole), and cotter pin.

(2) Open up the .375-inch diameter holes to .4750 plus or minus .0005-inch diameter. Install bushing and reinstall the original bolt, P/N 28-A24367, if within tolerances (i.e., .3745 plus .0000 minus .0003-inch diameter), or replace with new bolt, P/N 28-A24367. Use existing nut and washer, install new cotter pin. Remove all sharp edges. The bushings shall meet the following requirements:

Material: SAE 4130, MIL-S6758 condition "N". Cadmium plated.

Outside diameter: Before plating .4770 plus .0005 minus .0000-inch diameter.

After plating .4780 plus .0005 minus .0000-inch diameter.

Length: .748 plus .002 minus .000-inch for bushings in P/N 28-A24498 A and B.

.298 plus .002 minus .000-inch for bushings in P/N 28-A24670.

After installation, the bushings must be line reamed to their inside diameter of .3750 plus or minus .0005-inch. Chamfer inside of bushing .03-inch x 45 degrees, under head of bolt.

(b) Prior to installing bolts, shim the gap between the attachment lugs, P/N 28- A24498 A and B and the hingle brackets, P/N 28-A24670 to eliminate any movement. The torque value for either of the replacement bolts, P/N 28-A24367 or NAS 464-7-20 or equivalent, is 10 inch-pounds.

(c) After rework, holes must be line reamed to positively insure alinement. When the line reaming is done from outside and from underside of stabilizer, a 0.5-inch diameter hole is required in the horizontal stabilizer outer skin. If reamed from top, the spar cap may be removed locally to clear reamer. Rework of the skin shall be in accordance with Canadair Drawing 28- 22135.

(d) Fittings, P/N 28-A24498 A and B, and P/N 28-A24670 whose .375-inch diameter (original) holes are elongated beyond .4750-inch plus or minus .0005-inch must be replaced.

(e) Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, FAA Eastern Region, may adjust the repetitive inspection intervals specified in this AD to permit compliance at an established inspection period of the operator if the request contains substantiating data to justify the increase for such operator.

This directive effective November 1, 1961.