Airworthiness Directive · Amendment 39-17887 · Fuselage
The Boeing Company Airplanes
This AD applies to The Boeing Company airplanes, certificated in any category, identified in paragraphs (c)(1) and (c)(2) of this AD.
(1) All Model 707-100 long body, -200, -100B long body, and -100B short body series airplanes; and Model 707-300, -300B, -300C, and -400 series airplanes.
(2) All Model 720 and 720B series airplanes.
We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 707 airplanes, and Model 720 and 720B series airplanes. This AD was prompted by reports of scribe-line-related fatigue cracks on Model 727 airplanes, which are similar in design to Model 707 airplanes, and Model 720 and 720B series airplanes. This AD requires inspections for scribe lines in the skin lap joints, external approved repairs, external features, skin butt joints, and decals; and related investigative and corrective actions if necessary. This AD also requires surface finish restoration. We are issuing this AD to detect and correct scribe lines, which can develop into fatigue cracks in the skin and cause rapid decompression of the airplane.
(1) Except as specified in paragraphs (j)(1) and (j)(2) of this AD, at the applicable time specified in paragraph 1.E., “Compliance,” of Boeing 707 Alert Service Bulletin A3539, dated April 26, 2013: Do a detailed inspection of the fuselage skin for scribe lines, in accordance with the Accomplishment Instructions of Boeing 707 Alert Service Bulletin A3539, dated April 26, 2013. If no scribe line is found: Before further flight, do surface finish restoration, in accordance with the Accomplishment Instructions of Boeing 707 Alert Service Bulletin A3539, dated April 26, 2013.
(2) The inspection exceptions described in paragraph 1.E., “Compliance,” of Boeing 707 Alert Service Bulletin A3539, dated April 26, 2013, apply to paragraph (g)(1) of this AD.
If any scribe line is found during any inspection required by paragraph (g)(1) of this AD: At the applicable time specified in paragraph 1.E., “Compliance,” of Boeing 707 Alert Service Bulletin A3539, dated April 26, 2013, except as specified in paragraphs (j)(1) and (j)(2) of this AD, do all applicable related investigative and corrective actions, by doing all applicable actions specified in the Accomplishment Instructions of Boeing 707 Alert Service Bulletin A3539, dated April 26, 2013, except as specified in paragraph (j)(3) of this AD.
After completing any actions required by paragraph (h) of this AD: Before further flight, do surface finish restoration, in accordance with the Accomplishment Instructions of Boeing 707 Alert Service Bulletin A3539, dated April 26, 2013.
(1) Where paragraph 1.E., “Compliance,” of Boeing 707 Alert Service Bulletin A3539, dated April 26, 2013, specifies a compliance time “after the original issue date of this service bulletin,” this AD requires compliance within the specified compliance time after the effective date of this AD.
(2) Where the Condition column of paragraph 1.E., “Compliance,” of Boeing 707 Alert Service Bulletin A3539, dated April 26, 2013, refers to total flight cycles “as of the original issue date of this service bulletin,” this AD applies to the airplanes with the specified total flight cycles as of the effective date of this AD.
(3) Where Boeing 707 Alert Service Bulletin A3539, dated April 26, 2013, specifies to contact Boeing for additional inspections or repair instructions: Before further flight, repair the scribe line or cracking using a method approved in accordance with the procedures specified in paragraph (k) of this AD.
