Airworthiness Directive · Amendment 39-16746 · Hydraulic power
The Boeing Company Model 747-400 and -400D Series Airplanes
This AD applies to The Boeing Company Model 747-400 and -400D series airplanes, certificated in any category; as specified in Boeing Service Bulletin 747-29A2114, Revision 1, dated July 15, 2010.
We are adopting a new airworthiness directive (AD) for the products listed above. This AD requires a general visual inspection to determine the routing of the wire bundles in the number two and number three engine pylons near the leading edge, and related investigative and corrective actions if necessary. For certain airplanes, this AD also requires certain concurrent actions. This AD was prompted by a report of a fuel leak from the main fuel feed tube at the number two engine pylon. We are issuing this AD to detect and correct chafing of the main fuel feed tube and the alternating current motor-driven hydraulic pump wire bundle, which could lead to arcing from the exposed wire to the fuel feed tube, and could result in a fire or explosion.
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 24 months after the effective date of this AD, do a general visual inspection to determine the routing of the wire bundles in the number two and number three engine pylons near the leading edge, and do all applicable related investigative and corrective actions, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-29A2114, Revision 1, dated July 15, 2010. Do all applicable related investigative and corrective actions before further flight.
For Model 747-400 series airplanes: Before or concurrently with accomplishing the requirements of paragraph (g) of this AD, install all applicable cable support brackets in the number two and number three engine pylon areas, and do all applicable related investigative and corrective actions, in accordance with Phase II of Boeing Service Bulletin 747-24A2168, Revision 3, dated July 29, 1993. Do all applicable related investigative and corrective actions before further flight. Doing the actions required by paragraph (c) of AD 92-27-13, Amendment 39-8448, is an acceptable method of compliance for the installation required by this paragraph.
Note 1: For the purposes of this AD, a detailed inspection is: “An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirror, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate procedures may be required.”
(i) Actions accomplished before the effective date of this AD, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-29A2114, dated October 1, 2009, are considered acceptable for compliance with the corresponding actions specified in paragraph (g) of this AD.
(j) Actions accomplished before the effective date of this AD, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-24A2168, Revision 1, dated December 5, 1991; or Revision 2, dated September 24, 1992; are considered acceptable for compliance with the corresponding actions specified in paragraph (h) of this AD.
