Airworthiness Directive · Amendment 39-15588 · Boeing Model 737-300 and -400 Series Airplanes
Boeing Model 737-300 and -400 Series Airplanes
This AD applies to Boeing Model 737-300 and -400 series airplanes, certificated in any category; as identified in Boeing Special Attention Service Bulletin 737-57-1289, dated June 13, 2007.
We are adopting a new airworthiness directive (AD) for certain Boeing Model 737-300 and -400 series airplanes. This AD requires testing and inspecting a certain web panel of the main wheel well pressure deck to determine the material type and thickness; and related investigative and corrective actions if necessary. This AD results from several reports indicating that cracks ranging from 0.8 to 8.0 inches long were found on a certain web panel of the main wheel well pressure deck. We are issuing this AD to prevent fatigue cracking in the web panel of the main wheel well pressure deck, which could result in venting and consequent decompression of the airplane.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Within 6 months after the effective date of this AD: Do a test of the web panel of the main wheel well pressure deck to determine the material type, and do an ultrasonic inspection to determine material thickness, by doing all the applicable actions specified in the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-57-1289, dated June 13, 2007.
(g) For airplanes on which the web thickness or material is found to be discrepant during the test and inspection required by paragraph (f) of this AD, accomplish the applicable actions specified in paragraphs (g)(1) and (g)(2) of this AD at the time specified, in accordance with Boeing Special Attention Service Bulletin 737-57-1289, dated June 13, 2007.
(1) Except as provided by paragraph (h) of this AD: Do all applicable related investigative and corrective actions (including detailed and general visual inspections) before further flight, by doing all the actions specified in the Accomplishment Instructions of the service bulletin. Repeat the inspections thereafter at intervals not to exceed 1,000 flight cycles until the actions required by paragraph (g)(2) of this AD have been done. For any web panel with a material thickness of less than 0.037 inch, replace the web panel before further flight, in accordance with paragraph 3.B.7. of the Accomplishment Instructions of the service bulletin. Doing this replacement ends the repetitive inspections required by this paragraph.
(2) Except as required by paragraph (g)(1) of this AD: Within 30 months or 6,000 flight cycles after accomplishing the actions required by paragraph (g)(1) of this AD, whichever is later, replace the web panel in accordance with the Accomplishment Instructions of the service bulletin. Doing this replacement ends the repetitive inspections required by paragraph (g)(1) of this AD.
If any crack or corrosion is found during any inspection required by paragraph (g)(1) of this AD, and Boeing Special Attention Service Bulletin 737-57-1289, dated June 13, 2007, specifies to contact Boeing for repair instructions: Before further flight, repair according to a method approved in accordance with the procedures specified in paragraph (i) of this AD.
