Airworthiness Directive · Amendment 39-15494 · Boeing Model 737-300, -400, and -500 Series Airplanes
Boeing Model 737-300, -400, and -500 Series Airplanes
This AD applies to all Boeing Model 737-300, -400, and -500 series airplanes, certificated in any category.
We are adopting a new airworthiness directive (AD) for all Boeing Model 737-300, -400, and -500 series airplanes. This AD requires revising the FAA-approved maintenance inspection program to include inspections that will give no less than the required damage tolerance rating for each structural significant item (SSI), doing repetitive inspections to detect cracks of all SSIs, and repairing cracked structure. This AD results from a report of incidents involving fatigue cracking in transport category airplanes that are approaching or have exceeded their design service objective. We are issuing this AD to maintain the continued structural integrity of the entire fleet of Model 737-300, -400, and -500 series airplanes.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
The term “the SSID,” as used in this AD, means Boeing Document D6-82669, “Supplemental Structural Inspection Document Models 737-300/400/500 Airplanes,” Original Release, dated May 2007.
Before the accumulation of 66,000 total flight cycles, or within 12 months after the effective date of this AD, whichever occurs later, incorporate a revision into the FAA-approved maintenance inspection program that provides no less than the required damage tolerance rating (DTR) for each structural significant item (SSI) listed in the SSID. (The required DTR value for each SSI is listed in the SSID.) The revision to the maintenance inspection program must include and must be implemented in accordance with the procedures in Section 5.0, “Damage Tolerance Rating (DTR) System Application,” and Section 6.0, “SSI Discrepancy Reporting” of the SSID. Under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.), the Office of Management and Budget (OMB) has approved the information collection requirements contained in this AD and has assigned OMB Control Number 2120-0056.
Except as provided by paragraph (i) of this AD: Before the accumulation of 66,000 total flight cycles, or within 4,000 flight cycles measured from 12 months after the effective date of this AD, whichever occurs later, do the applicable initial inspections to detect cracks of all SSIs, in accordance with the SSID. Repeat the applicable inspections thereafter at the intervals specified in Section 3.0, “Implementation” of the SSID.
(i) For any SSI that has been repaired or altered before the effective date of this AD such that the repair or design change affects your ability to accomplish the actions required by paragraph (h) of this AD: You must request FAA approval of an alternative method of compliance (AMOC) in accordance with section 39.17 of the Federal Aviation Regulations (14 CFR 39.17), at the initial compliance time specified in paragraph (h) of the AD; or do the actions specified in paragraphs (i)(1) and (i)(2) of this AD, at the times specified in those paragraphs, as an approved means of compliance with the requirements of paragraph (h) of this AD.
(1) At the initial compliance time specified in paragraph (h) of the AD, identify each repair or design change to that SSI.
(2) Within 12 months after the identification of a repair or design change required by paragraph (i)(1) of this AD, assess the damage tolerance characteristics of each SSI affected by each repair or design change to determine the effectiveness of the applicable SSID inspection for that SSI and if not effective, incorporate a revision into the FAA-approved maintenance inspection program to include a damage-tolerance based alternative inspection program for each affected SSI. Thereafter, inspect the affected structure in accordance with the alternative inspection program. The inspection method and compliance times (i.e., threshold and repeat intervals) of the alternative inspection program must be approved in accordance with the procedures specified in paragraph (l) of this AD.
If any cracked structure is found during any inspection required by paragraph (h) or (i) of this AD, before further flight, repair the cracked structure using a method approved in accordance with the procedures specified in paragraph (l) of this AD.
Before any airplane that is subject to this AD and that has exceeded the applicable compliance times specified in paragraph (h) of this AD can be added to an air carrier's operations specifications, a program for the accomplishment of the inspections required by this AD must be established in accordance with paragraph (k)(1) or (k)(2) of this AD, as applicable.
(1) For airplanes that have been inspected in accordance with this AD: The inspection of each SSI must be done by the new operator in accordance with the previous operator's schedule and inspection method, or the new operator's schedule and inspection method, at whichever time would result in the earlier accomplishment for that SSI inspection. The compliance time for accomplishment of this inspection must be measured from the last inspection accomplished by the previous operator. After each inspection has been done once, each subsequent inspection must be performed in accordance with the new operator's schedule and inspection method.
(2) For airplanes that have not been inspected in accordance with this AD: The inspection of each SSI required by this AD must be done either before adding the airplane to the air carrier's operations specification, or in accordance with a schedule and an inspection method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA. After each inspection has been done once, each subsequent inspection must be done in accordance with the new operator's schedule.
