74-02-02 SL INDUSTRIES, INC: Amendment 39-1770. Applies to all Models B-1 and B-1A airplanes, certificated in all categories, and originally manufactured by either CallAir, Intermountain Company, Aero Commander or North American Rockwell Corporation.
Compliance required within the next 100 hours' time in service after the effective date of this AD, unless already accomplished.
To prevent failure of the front wing spar, accomplish the following:
(a) Inspect both front wing spars by the following procedures:
(1) Remove the P/N 16161 wing leading edge panels between the wing-body junction and the MLG shock strut by drilling out the necessary rivets.
(2) Remove the wing fairing covering the front spar attach bolt.
(3) Hoist the wing and jack the landing gear to relieve the load on the front spar attach bolt and remove the front spar attach bolt.
(4) Remove the P/N 16045-1 and -2 spar fittings by removal of (10) AN4 bolts attaching fittings to thespar web.
(5) Visually and with dye penetrant methods, inspect the spar web in the area of the P/N 16045-1 and -2 fittings for cracks. Give particular attention to the upper and lower fastener locations in the pattern of (10) fasteners attaching the P/N 16045-1 and -2 fittings to the spar web. Inspect these holes for elongation beyond .254 inches.
(6) Visually inspect the inboard 24 inches of the spar web for corrosion.
(b) Repair discrepancies found during the inspections of paragraph (a) as follows:
(1) For cracks or elongated fastener holes in the spar web, replace the damaged spar with a new spar.
(2) For corrosion on the spar web, repair as follows:
(i) Remove corrosion in accordance with AC 43.13-1.
(ii) If corrosion is less than 10% of spar web thickness locally and reduces the spar web cross-section area by less than 2%, treat the corroded spar web area with two coats of zinc chromate primer in accordance with MIL-P-6889 or MIL-P-8585A.
(iii) If corrosion exceeds 10% of local spar web thickness or 2% of spar web cross- section area, replace the spar or repair with a repair approved by the Chief, Engineering and Manufacturing Branch, FAA, Southwest Region.
(c) Reinstall the 16045-1 and -2 spar fittings.
(d) Install the 16246 and 16247 spar fittings in accordance with Service Bulletin A- 15.
(e) Reinstall the wing fairings and leading edge panels removed during paragraph (a) inspections.
NOTE: (SL Industries Service Bulletin A-24 covers this same subject.)
The manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to the General Manager, SL Industries, Inc., 7020 West Wilshire, Oklahoma City, Oklahoma 73132. These documents may also beexamined at the office of the Regional Counsel, Southwest Region, FAA, 4400 Blue Mound Road, Fort Worth, Texas and at FAA headquarters, 800 Independence Avenue, S.W., Washington, D.C. A historical file on this AD which includes the incorporated material in full is maintained by the FAA at its headquarters in Washington, D.C., and at the Southwest Regional Office in Fort Worth, Texas.
This amendment becomes effective January 18, 1974.