Airworthiness Directive · Amendment 39-14350 · Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747SR, and 747SP Series Airplanes
Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747SR, and 747SP Series Airplanes
This AD applies to Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747SR, and 747SP series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 747-53A2508, dated August 19, 2004.
The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747- 200C, 747-200F, 747-300, 747SR, and 747SP series airplanes. This AD requires doing a one-time high-frequency eddy current inspection and repetitive detailed inspections for cracks in the frame web of main entry door number 1; and repairing the door frame web if necessary. This AD also provides for optional terminating action for the repetitive inspections. This AD is prompted by reports of cracking at the upper aft corner of the cutout for main entry door number 1 in the station 488 frame web. We are issuing this AD to detect and correct cracks in the frame web. These cracks could cause the frame to break and lead to 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.
Before the accumulation of 16,000 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later, do a high frequency eddy current (HFEC) inspection and a detailed inspection of the station 488 frame web, by doing all of the actions specified in the Accomplishment Instructions of Boeing Alert Service Bulletin (ASB) 747-53A2508, dated August 19, 2004; except as provided by paragraph (h) or (j) of this AD.
If no crack is found during the inspections required by paragraph (f) of this AD, do the applicable actions specified in paragraph (g)(1) or (g)(2) of this AD.
(1) For airplanes identified in the service bulletin as Groups 1 and 2: Repeat the detailed inspection required by paragraph (f) of this AD at intervals not to exceed 3,000 flight cycles.
(2) For airplanes identified in the service bulletin as Group 3, do the actions specified in either paragraph (g)(2)(i) or (g)(2)(ii) of this AD.
(i) Repeat the detailed inspection required by paragraph (f) of this AD thereafter at intervals not to exceed 1,500 flight cycles.
(ii) Within 1,500 flight cycles after the inspections required by paragraph (f) of this AD, perform a HFEC inspection for cracks of the frame web between the upper door sill and door stop number 8 in accordance with the method referenced in Figure 3 or Figure 4 of the Accomplishment Instructions of the service bulletin. Repeat the HFEC inspection thereafter at intervals not to exceed 3,000 flight cycles.
If any crack in the main entry door frame web is found during any inspection required by this AD: Before further flight, perform repairs—including an open-hole HFEC inspection of the frame inner chord—in accordance with the Accomplishment Instructions of Boeing ASB 747-53A2508, dated August 19, 2004. Where the service bulletin specifies to contact Boeing for appropriate action: Before further flight, repair the door frame web and any frame chord damage using a method approved in accordance with paragraph (k) of this AD.
Note 1: Boeing ASB 747-53A2508, dated August 19, 2004, references the Boeing Structural Repair Manual as an additional source of service information to comply with the intent of paragraph (h) this AD.
(i) For the repaired frame web only, accomplishing the door frame web repair required by paragraph (h) of this AD ends the repetitive inspections required by paragraph (g) of this AD.
(j)(1) If the frame inner chord replacement required by AD 90-06-06, amendment 39-6490, (which identifies Boeing Service Bulletin 747-53-2272, as listed in Boeing Document No. D6-35999, dated March 31, 1989, as a source of service information) is accomplished concurrently with the repair of the station 488 door frame web specified by paragraph (h) of this AD, the open-hole HFEC inspection required by paragraph (h) of this AD is not required for the new frame inner chord.
(2) Accomplishing the repetitive detailed inspections of the station 488 frame required by paragraph (f) of AD 2005-20-30, amendment 39-14327, or paragraph (f) of AD 2005-08-01, amendment 39-14053, satisfies the requirements for the corresponding repetitive detailed inspections described by paragraphs (g)(1) and (g)(2)(i) of this AD, provided those inspections are performed at intervals corresponding with the applicable intervals required by this AD.
