Airworthiness Directive · Amendment 39-14296 · Boeing Model 737-100, -200, -200C, -300, -400, and -500 Series Airplanes
Boeing Model 737-100, -200, -200C, -300, -400, and -500 Series Airplanes
Superseded. A later AD replaced this one: AD 2009-16-14. Comply with the one in force.
This AD applies to Model 737-100, -200, -200C, -300, -400, and -500 series airplanes, as identified in Boeing Special Attention Service Bulletin 737-53-1204, dated June 19, 2003; certificated in any category.
The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. This AD requires repetitive inspections of the intercostal webs, attachment clips, and stringer splice channels for cracks; and corrective action if necessary. This AD is prompted by reports of fatigue cracks on several Boeing Model 737-200 series airplanes. We are issuing this AD to detect and correct fatigue cracking of the intercostals on the forward and aft sides of the forward entry door, which could result in loss of the forward entry door and rapid 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.
The term “service bulletin,” as used in this AD, means Boeing Special Attention Service Bulletin 737-53-1204, dated June 19, 2003.
Before the accumulation of 15,000 total flight cycles, or within 4,500 flight cycles after the effective date of this AD, whichever occurs later: Do the inspections specified in paragraph (h) or (i) of this AD, as applicable.
For Group 1 passenger airplanes identified in the service bulletin: Perform a detailed inspection of the intercostal web, attachment clips, and stringer splice channels for cracks; and a high frequency eddy current inspection of the stringer splice channels, located forward and aft of the forward entry door, for cracks; per Parts 1 and 2 of the Work Instructions of the service bulletin.
(i) For Group 2 cargo airplanes identified in the service bulletin: Perform a detailed inspection of the intercostal webs and attachment clips located forward of the forward entry door for cracks, per Part 3 of the Work Instructions of the service bulletin.
If no crack is found during any inspection required by paragraph (h) or (i) of this AD, repeat the inspections in paragraph (h) or (i) of this AD at the applicable time specified in Table 1 of this AD, except as provided by paragraph (k) of this AD.
| Airplane group number in Service Bulletin | For intercostal location— | Repeat inspections at intervals not to exceed— |
|---|---|---|
| Group 1 | Stringer-16L (S-16L), from Body Stringer 348.2 to BS 360 (aft of door) | 4,500 flight cycles. |
| Group 1 | S-7L through S-15L, from BS 348.2 to BS 360 (aft of door) | 25,000 flight cycles. |
| Group 1 and 2 | S-7L through S-16L, from BS 294.5 to BS 303.9 (forward of door) | 25,000 flight cycles. |
For intercostal webs at S-16L from BS 348.2 to BS 360: Installation of the repair as a preventative modification or corrective action per Part 1 of the Work Instructions of the service bulletin defers the repetitive inspections to intervals not to exceed 25,000 flight cycles. For Model 737-400 series airplanes, use 737-400 Structural Repair Manual (SRM) 53-10-04, Figure 201, instead of Figure 202.
If any crack is found during any inspection required by paragraph (h) or (i) of this AD, perform the actions specified in paragraphs (l)(1) through (l)(3) of Table 2 of this AD, as applicable. Repeat the inspections at the applicable time specified in Table 1 of this AD, except as provided by paragraph (k) of this AD.
| During any inspection specified in— | If any crack is found in— | At intercostal location— | Before further flight— |
|---|---|---|---|
| (1) Part 1 of the Work Instructions of the service bulletin | (i) The intercoastal web | S-16L, from BS 348.2 to BS 360 (aft of door) | Repair per Part 1 of the Work Instructions of the service bulletin, except the service bulletin specifies to contact Boeing for repair instructions, before further flight, do the repair specified in paragraph (m) of this AD. Use 737-400 SRM 53-10-04, Figure 201, instead of Figure 202, as applicable (see Note 1). |
| (ii) An attachment clip or stringer splice channel | S-16L, from BSDo 348.2 to BS 360 (aft of door) | Do the repair specified in paragraph (m) of this AD. | |
| (2) Part 2 of the Work Instructions of the service bulletin | An intercoastal web, attachment clip, or stringer splice channel | S-7L through S-16L, from BS 294.5 to BS 303.9 (forward of door); and S-7L through S-15L, from BS 348.2 to BS 360 (aft of door) | Do the repair specified in paragraph (m) of this AD. |
| (3) Part 3 of the Work Instructions of the service bulletin | An intercoastal web or attachment clip | S-7L through S-16L, from BS 294.5 to BS 303.9 (forward of door) | Do the repair specified in paragraph (m) of this AD. |
Note 1: The service bulletin specifies to repair any crack found at the S-16L intercostal (BS 348.2-360) on Boeing Model 737-400 series airplanes per 737-400 SRM 53-10-04, Figure 202. Figure 202 does not exist; the correct figure is 737-400 SRM 53-10-04, Figure 201.
At the time specified in Table 2 of this AD, repair per a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or per data meeting the type certification basis of the airplane approved an Authorized Representative for the Boeing Delegation Option Authorization Organization who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane and the approval must specifically refer to this AD.
