Airworthiness Directive · Amendment 39-14384 · Boeing Model 767-300 Series Airplanes
Boeing Model 767-300 Series Airplanes
This AD applies to Boeing Model 767-300 series airplanes, certificated in any category; as identified in Boeing Service Bulletin 767-25-0334, Revision 1, dated June 19, 2003.
The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 767-300 series airplanes. This AD requires replacing the frequency converters used to supply power for medical and galley utility outlets with modified frequency converters, and related actions. This AD results from a report indicating that a hard short circuit condition between the output of certain frequency converters and their downstream circuit breakers will produce a continuous output current that could cause the undersized output wiring to overheat when the frequency converters fail to shut off. We are issuing this AD to prevent overheating of the output wiring of the frequency converters, which could result in the failure of a wire bundle and consequent adverse effects on other systems sharing the affected wire bundle.
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 18 months after the effective date of this AD, do the actions specified in either paragraph (f)(1) or (f)(2) of this AD.
(1) Replace the frequency converters used to supply power for medical and galley utility outlets with modified frequency converters, and do any related actions, by doing all of the actions specified in the Accomplishment Instructions of Boeing Service Bulletin 767-25-0334, Revision 1, dated June 19, 2003.
(2) Remove and deactivate the frequency converters used to supply power for medical and galley utility outlets, and cap and stow the frequency converter wire bundles, in accordance with B.1. through B.6. of the Accomplishment Instructions of Boeing Service Bulletin 767-25-0334, Revision 1, dated June 19, 2003. As of the effective date of this AD, no person may install a frequency converter that has been removed and deactivated in accordance with this paragraph, unless it is modified in accordance with the Accomplishment Instructions of the service bulletin.
Actions done before the effective date of this AD in accordance with Boeing Service Bulletin 767-25-0334, dated November 7, 2002, are acceptable for compliance with the requirements of paragraph (f) of this AD.
