63-11-01 BOEING: Amdt. 568 Part 507 Federal Register May 23, 1963. Applies to All Models 707 and 720 Aircraft. \n\n\tCompliance required within the next 100 hours' time in service after the effective date of this AD and thereafter at intervals not exceeding 100 hours' time in service and as indicated in paragraphs (d) and (e). \n\n\tAs a result of failures of the landing gear truck beam and related components, accomplish the following: \n\n\t(a) Clean the truck beams in accordance with the following: \n\n\t\t(1) Prerinse the area using Stoddard Solvent P-S-661 type 1 or water. \n\n\t\t(2) Using a soft bristle or fiber brush, apply one of the following cleansing agents, or equivalent approved by FAA Engineering and Manufacturing Branch, Western Region to the soiled areas: \n\n\t\t\t(i) Oakite 204, full strength; \n\n\t\t\t(ii) Oakite 74L, one part with five parts water; \n\n\t\t\t(iii) Wyandotte Aerowash A, full strength; \n\n\t\t\t(iv) Kelite Formula 29, full strength; \n\n\t\t\t(v) An emulsion cleaner listed in Chapter 13 of Boeing Overhaul Manual; and \n\n\t\t\t(vi) An emulsion cleaner tested in accordance with Boeing Document D6- 17487, dated August 24, 1965, or later revision. \n\n\t\t(3) Allow cleansing agent to remain on the parts for 5 minutes. Do not permit the area to dry. Agitate the cleaner applied to beam and allow to remain on the parts an additional 5 minutes. Agitate again with the brush and thoroughly pressure rinse with water, preferably warm, but not exceeding 120 degrees F. In lieu of, or as a supplement to the pressure rinse with water, the cleaners may be removed by use of solvents listed in Chapter 13 of Boeing Overhaul Manual. \n\n\t(b) After cleaning, make a thorough visual inspection of the truck beam using mirrors as necessary and a strong light to detect any evidence of jack marks, scratches, gouges, corrosion or impact dents. Remove any straps around the beam which show evidence of damage. Particular attention shall be given to: \n\n\t\t(1) The lower section of the beam for evidence of jack marks caused by jack slippage or improperly placed jacks; \n\n\t\t(2) The forward area of the beam where contact is possible with the torsion link pivot pin retaining bolt (on the lower torque link lug on the Model 720); and, \n\n\t\t(3) To the aft area of the beam where contact is possible with the shock strut inner cylinder upon snubber failure. \n\n\t(c) Truck beams exhibiting evidence of corrosion, scratches, jack marks, dents or gouges shall be replaced before further flight unless repaired in accordance with FAA approved Boeing Service Bulletin No. 142(R-2) or later FAA approved revisions. Evidence of jack marks or dents shall be inspected with a dial indicator or FAA approved equivalent to determine the depth of such damage. No repair is permitted if the depth exceeds 0.005 inch. \n\n\t(d) Before further flight after any jacking operations and after main landing gear snubber failure, clean and inspect the truck beam as follows: \n\n\t\t(1) Clean truck beam with one of the approved Boeing solvents for cleaning of high heat-treated steel listed in Chapter 13 of the Boeing Overhaul Manual. \n\n\t\t(2) Inspect and, as necessary, rework or replace the truck beam in accordance with paragraphs (b) and (c). \n\n\t\t(3) If a truck beam shield is fabricated and installed in accordance with American Airlines Engineering Change Order No. B1743, dated October 8, 1962, or FAA Western Region Engineering approved equivalent is installed, the following inspection procedure for the truck beam area protected by the shield may be followed in lieu of that required by (d)(1) and (2): \n\n\t\t\t(i) Clean the truck beam shield with Navee 427 or FAA approved equivalent, and inspect it for evidence of dents, gouges, cracks, pressure marks, or other damage. \n\n\t\t\t(ii) If no evidence of dents, gouges, cracks, pressure marks or other damage is found, further inspection of the truck beam area protected by the shield is not required at this inspection period. \n\n\t\t\t(iii) If evidence of dents, gouges, cracks, pressure marks, or other damage is found, remove the shield and clean and inspect the truck beam in accordance with (d)(1) and (2). If the shield is still serviceable, it may be reinstalled provided that any dents, gouges, cracks, pressure marks, or other damage is painted over with yellow paint to indicate old damage. \n\n\tNOTE: When a shield is installed on the truck beam in compliance with paragraph (d)(3) compliance with the remaining provisions of the AD is still required. \n\n\t\t(4) If a Boeing truck beam shield is fabricated and installed in accordance with Boeing Service Bulletin No. 1780 or FAA Western Region Engineering approved equivalent, the following inspection procedure for the truck beam area protected by the shield may be followed in lieu of that required by (d)(1) and (2): \n\n\tNOTE: The British Overseas Airways Corporation truck beam shield manufactured and installed in accordance with BOAC Drawing No. BOA-B61138 is an approved equivalent to the Boeing truck beam shield. \n\n\t\t\t(i) Clean and inspect the truck beam shield for any evidence of impact damage such as dents. \n\n\t\t\t(ii) If no evidence of impact damage is found, further inspection of the truck beam area protected by the shield is not required at this inspection period. \n\n\t\t\t(iii) If the shield is distorted to the extent that contact with the beam is obvious or suspected, remove the shield and clean and inspect the truck beam in accordance with (d)(1) and (2). If the shield is still serviceable, it may be reinstalled provided that any impact damage is painted over with yellow paint to indicate old damage. \n\n\t\t\t(iv) At intervals not to exceed 600 hours' time in service after original installation of the shield, visually inspect the truck beam for evidence of foreign matter between the truck beam and the shield, or corrosion on the truck beam. If foreign matter is present, clean the truck beam and shield as necessary.If corrosion is present, remove the corrosion in accordance with Boeing FAA approved Service Bulletin No. 142 (R-2) or later FAA approved revision. \n\n\t\t\t(v) At intervals not to exceed 5,550 hours' time in service after original installation of the shield, remove the shield and inspect for corrosion. Remove any corrosion present in accordance with Boeing FAA approved Service Bulletin No. 142(R-2) or later FAA approved revisions. \n\n\t(e) The 100-hours repetitive inspection interval may be increased to 600 hours' time in service when the automatic brake cylinder and the piston in the main landing gear metering valve are replaced with new Boeing actuator assembly 69-10763, and the landing gear snubber assembly and main landing gear centering cylinders have been reworked in accordance with Boeing Service Bulletins Nos. 535 and 535B. Concurrently with the increase to 600 hour repetitive inspection interval, the cleaning procedures of paragraph (d) may be used in lieu of those of paragraph (a). \n\n\tNOTE: Some aircraft have been modified prior to delivery to incorporate the work required by Boeing Service Bulletins No. 535 and 535B. \n\n\t(f) The main landing gear shall not be jacked and/or supported at points other than the forward and aft truck beam jack pads, unless the aircraft is otherwise supported in accordance with Section 32 of the Boeing Maintenance Manual. \n\n\t(g) Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, FAA Western 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. \n\n\t(Boeing Service Bulletin No. 142(R-2) covers this same subject.) \n\n\tThis supersedes AD 62-17-02. \n\n\tThis directive effective May 23, 1963. \n\n\tRevised August 13, 1964. \n\n\tRevised May 17, 1966.