60-06-01 BOEING: Amdt. 111 Part 507 Federal Register March 8, 1960. Applies to Models 707 and 720 Series Airplanes Equipped with Nose Gear Outer Cylinder, Boeing P/N 5-83025- 3005. \n\n\tCompliance required as indicated. \n\n\tDue to failures found in the nose landing gear outer cylinder as a result of initial defects, the following inspections are required unless already accomplished:\n \n\t(a) Conduct a daily visual inspection with a 10-power magnifying glass for cracks in the outer surface of the nose gear outer cylinder in the upper barrel area of the trunnion, and in the area below the towing collar. Outer cylinders with cracks appearing on the outer surface must be replaced prior to further flight. Further inspection is not required on replacement part. This inspection must be continued until item (b) is accomplished. \n\n\t(b) Within 20 calendar days, inspect the areas described in (a) with probe type ultrasonic shear wave equipment or equivalent. Outer cylinders with cracks on the outer surface or with crack indications that exceed 1 inch in length must be replaced prior to further flight. Cylinders with crack indications 1 inch or less in length may be retained in service, provided: \n\n\t\t(1) A daily visual inspection as in (a) is continued and the ultrasonic inspections or equivalent are repeated every 20 landings. \n\n\t\t(2) A dye penetrant inspection or equivalent of the interior surface of the outer cylinder is accomplished within 550 hours' time in service and every 550 hours' time in service thereafter. \n\n\t(c) If no cracks or crack indications are found by inspections (a) and (b), the nose landing gear may revert to normal inspection procedures and periods except for accomplishing (d). \n\n\t(d) Conduct a dye penetrant inspection or equivalent for cracks on the interior surface of all nose gear outer cylinders within the next 3,000 hours' time in service. Outer cylinders with cracks on the interior surface that exceed 1 inch in length or that extend to the outer surface must be replaced prior to further flight. Cylinders with cracks 1 inch or less in length on the interior surface may be retained in service provided the cracks do not extend to the outer surface and the cylinders are inspected in accordance with (b)(1) and (b)(2). Operators may accomplish this inspection within the next 1,500 landings occurring subsequent to March 8, 1960, in lieu of the next 3,000 hours' time in service. (It will be necessary for operators to maintain a record of landings to ascertain compliance. If past records are unavailable, the number of prior landings may be estimated.) \n\n\t(Boeing Wire Service Bulletin No. 739 pertains to the above subject.) \n\n\tRevised November 18, 1960.\n \n\tRevised May 14, 1966.