Airworthiness Directive · Amendment 39-16621 · Nacelles/pylons
The Boeing Company 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 The Boeing Company 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 747-54A2203, Revision 2, dated July 9, 2009.
We are superseding an existing airworthiness directive (AD) for the products listed above. That AD currently requires repetitive inspections and torque checks of the hanger fittings and strut forward bulkhead of the forward engine mount and adjacent support structure, and visual inspections of the internal angle and external bulkhead chord and detailed inspection of internal angles, and corrective actions if necessary. The existing AD also provides for an optional inspection. This new AD requires additional inspections of airplanes that have hi-lok bolts and collars at all of the Group B fastener locations, except fastener 13, and related investigative and corrective actions. This AD also requires repetitive inspections of the internal angle, and corrective actions if necessary. This AD also requires, for certain airplanes, replacing the fasteners, which terminates certain repetitive inspections. This AD was prompted by reports of undertorqued or loose fasteners, a cracked bulkhead chord, and a fractured back-up angle. We are issuing this AD to detect and correct loose fasteners and/or damaged or cracked hanger fittings, back-up angles, and bulkhead of the forward engine mount, which could lead to failure of the hanger fitting and bulkhead and consequent separation of the engine from 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.
Except as provided by paragraphs (i), (l), and (n) of this AD: At the applicable compliance times and repeat intervals listed in Tables 1 and 2 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-54A2203, Revision 1, dated August 9, 2007, do the inspections and applicable related investigative and corrective actions in accordance with Parts 2 and 8 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-54A2203, Revision 1, dated August 9, 2007; or Revision 2, dated July 9, 2009. After the effective date of this AD, use only Boeing Alert Service Bulletin 747-54A2203, Revision 2, dated July 9, 2009.
For all airplanes: Except as provided by paragraph (m) of this AD, at the applicable time in Table 2 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-54A2203, Revision 2, dated July 9, 2009, do the initial inspection and related investigative and corrective actions in accordance with Part 7 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-54A2203, Revision 2, dated July 9, 2009, except as required by paragraphs (k) and (n) of this AD. Repeat the inspection thereafter at the applicable time in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-54A2203, Revision 2, dated July 9, 2009.
(i) For airplanes that were inspected in accordance with in Boeing Alert Service Bulletin 747-54A2203, dated August 31, 2000; or Revision 1, dated August 9, 2007; and that have hi-lok bolts and collars at all of the Group B fastener locations: Except as provided by paragraph (m) of this AD, at the applicable time in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-54A2203, Revision 2, dated July 9, 2009, do the initial inspection and related investigative and corrective actions in accordance with Part 2 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-54A2203, Revision 2, dated July 9, 2009, except as required by paragraph (n) of this AD. Repeat the inspection at the applicable interval in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-54A2203, Revision 2, dated July 9, 2009.
For airplanes that were inspected in accordance with Boeing Alert Service Bulletin 747-54A2203, dated August 31, 2000, and that have hi-lok bolts and collars at all of the Group B fastener locations: Within 18 months after the effective date of this AD, replace all hi-lok Group B fasteners in accordance with Part 6 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-54A2203, Revision 2, dated July 9, 2009. Repeat the inspection required by Part 2 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-54A2203, Revision 2, dated July 9, 2009, at the applicable interval specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-54A2203, Revision 2, dated July 9, 2009.
Where Step 3 of Part 7 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-54A2203, Revision 1, dated August 9, 2007; or Revision 2, dated July 9, 2009; provides the option to support the engine weight instead of removing the engine, this AD does not allow that option. This AD requires that the engine be removed before performing the inspections required by paragraph (h) of this AD.
(l) Where Boeing Alert Service Bulletin 747-54A2203, Revision 1, dated August 9, 2007, specifies a compliance time after the date of that service bulletin, this AD requires compliance within the specified compliance time after October 9, 2007 (the effective date of AD 2007-19-19).
(m) Where Boeing Alert Service Bulletin 747-54A2203, Revision 2, dated July 9, 2009, specifies a compliance time after the date of Revision 1 or Revision 2 of that service bulletin, this AD requires compliance within the specified compliance time after the effective date of this AD.
(n) Where Boeing Alert Service Bulletin 747-54A2203, Revision 1, dated August 9, 2007; or Boeing Alert Service Bulletin 747-54A2203, Revision 2, dated July 9, 2009; specifies to contact Boeing for appropriate action, this AD requires, before further flight, repair of the discrepancy or replacement of the discrepant part using a method approved in accordance with the Boeing Commercial Airplanes Organization Designation Authorization or in accordance with the procedures specified in paragraph (p) of this AD.
Actions performed before the effective date of this AD, in accordance with Boeing Alert Service Bulletin 747-53A2203, Revision 1, dated August 9, 2007, are acceptable for compliance with the corresponding actions specified in paragraphs (h), (i), and (j) of this AD.
