Airworthiness Directive · Amendment 39-17787 · Fuselage
The Boeing Company Airplanes
This AD applies to The Boeing Company Model 727, 727C, 727-100, 727-100C, 727-200, and 727-200F series airplanes, certificated in any category, having line position 1433 through 1832 inclusive, identified as Group 2 airplanes in Boeing Service Bulletin 727-53-0149, Revision 4, dated June 27, 1991.
We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 727 airplanes. This AD was prompted by certain mandated programs intended to support the airplane reaching its limit of validity of the engineering data that support the established structural maintenance program. This AD requires an inspection for cracks in the main wheel well pressure floor and a preventive modification or permanent repair, as applicable. We are issuing this AD to prevent cracking in the main wheel well pressure floor, which could result in reduced structural integrity of the airplane, and decompression of the cabin.
For the purposes of this AD, a detailed inspection is an intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirrors, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate procedures may be required.
At the later of the times specified in paragraphs (h)(1) and (h)(2) of this AD: Do a one-time detailed, high frequency eddy current (HFEC), or dye penetrant inspection for cracks in the main wheel well pressure floor at body stations 930, 940, and 950, between left and right buttock line 50 and the side of the airplane body, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 727-53-0149, Revision 4, dated June 27, 1991.
(1) Prior to the accumulation of 60,000 total flight cycles; or
(2) Within 2,500 flight cycles or 2 years after the effective date of this AD, whichever occurs first.
Note 1 to paragraph (h) of this AD: If a detailed inspection is performed, stripping the paint will help ensure accurate inspection results.
If no cracks are found during the inspection required by paragraph (h) of this AD: Before further flight, do the preventive modification, in accordance with Part IV of the Accomplishment Instructions of Boeing Service Bulletin 727-53-0149, Revision 4, dated June 27, 1991. Doing the preventive modification terminates the repetitive inspections required by paragraph (d) of AD 92-19-11, Amendment 39-8369 (57 FR 53247, November 9, 1992).
If any crack is found during the inspection required by paragraph (h) of this AD: Before further flight, do the permanent repair, in accordance with Part III of the Accomplishment Instructions of Boeing Service Bulletin 727-53-0149, Revision 4, dated June 27, 1991. Doing the permanent repair terminates the repetitive inspections required by paragraph (d) of AD 92-19-11, Amendment 39-8369 (57 FR 53247, November 9, 1992).
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Aircraft
