Airworthiness Directive · Amendment 39-15670 · Boeing Model 737-300, -400, and -500 Series Airplanes
Boeing Model 737-300, -400, and -500 Series Airplanes
Superseded. A later AD replaced this one: AD 2012-12-04. Comply with the one in force.
This AD applies to Boeing Model 737-300, -400, and -500 series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 737-53A1293, dated August 13, 2008.
We are adopting a new airworthiness directive (AD) for certain Boeing Model 737-300, -400, and -500 series airplanes. This AD requires repetitive external detailed inspections or non-destructive inspections to detect cracks in the fuselage skin along the chem-mill steps at stringers S-1 and S-2R, between station (STA) 400 and STA 460, and repair if necessary. This AD results from reports of cracks in the fuselage skin common to stringer S-1 and between STA 400 and STA 460. We are issuing this AD to detect and correct fatigue cracking of the fuselage skin panels at the chem-mill steps, which could result in sudden fracture and failure of the fuselage skin panels, and consequent rapid decompression of the airplane.
Comply with this AD within the compliance times specified, unless already done.
At the applicable times specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-53A1293, dated August 13, 2008 (hereafter “the service bulletin”); except where the service bulletin specifies a compliance time after the date on the service bulletin, this AD requires compliance within the specified compliance time after the effective date of this AD: Do repetitive external detailed inspections or non-destructive inspections (NDI) to detect cracks in the fuselage skin along the chem-mill steps at stringers S-1 and S-2R, between STA 400 and STA 460, by accomplishing the applicable inspections specified in the Accomplishment Instructions of the service bulletin.
If any crack is found during any inspection required by paragraph (f) of this AD, before further flight, repair the cracked fuselage skin using a method approved in accordance with the procedures specified in paragraph (h) of this AD.
