Airworthiness Directive · Amendment 39-15254 · Boeing Model 747-400, 747-400D, and 747-400F Series Airplanes; Model 757-200 Series Airplanes; and Model 767-200, 767-300, and 767-300F Series Airplanes
Boeing Model 747-400, 747-400D, and 747-400F Series Airplanes; Model 757-200 Series Airplanes; and Model 767-200, 767-300, and 767-300F Series Airplanes
This AD applies to the Boeing airplane models, certificated in any category, identified in the service bulletins specified in Table 1 of this AD.
| Boeing model— | As identified in Boeing Special Attention Service Bulletin— |
|---|---|
| 747-400, 747-400D, and 747-400F series airplanes | 747-26-2281, dated July 24, 2006. |
| 757-200 series airplanes | 757-26-0051, dated July 28, 2006. |
| 767-200, -300, and -300F series airplanes | 767-26-0131, dated July 24, 2006. |
The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 747-400, 747-400D, 747-400F, 757-200, 767-200, 767-300, and 767-300F series airplanes. This AD requires inspecting to determine the date code of the time delay relay for the cargo fire suppression system, and replacing the relay if necessary. This AD results from a report indicating that failure of a time delay relay on an ELMS (electrical load management system) panel led to testing of other time delay relays at Boeing and at the supplier. Similar relays are used in the cargo fire suppression system. The time delay relay controls when the secondary fire bottles discharge. We are issuing this AD to ensure there is sufficient fire suppressant to control a cargo fire if the airplane is more than the relay delay time from a suitable airport, which could result in an uncontrollable fire in the cargo compartment.
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 the Accomplishment Instructions of the following service bulletins, as applicable:
(1) For Model 747-400, 747-400D, and 747-400F series airplanes: Boeing Special Attention Service Bulletin 747-26-2281, dated July 24, 2006;
(2) For Model 757-200 series airplanes: Boeing Special Attention Service Bulletin 757-26-0051, dated July 28, 2006; and
(3) For Model 767-200, -300, and -300F series airplanes: Boeing Special Attention Service Bulletin 767-26-0131, dated July 24, 2006.
Within 24 months after the effective date of this AD: Do a general visual inspection of the part number (P/N) TDH6103-1204, -1804, and -6003 time delay relay, as applicable, in the main equipment center to determine if the relay was manufactured during a certain date range, in accordance with the applicable service bulletin.
Within 30 days after finding a relay manufactured during the date range specified in the service bulletin, as required by paragraph (g) of this AD: Replace the relay with a relay that was not manufactured during the specified date range, or with a relay that has been tested by the supplier and found to be unaffected by thermal expansion, in accordance with the applicable service bulletin.
(i) As of the effective date of this AD, no person may install a time delay relay, P/N TDH6103-1204, -1804, or -6003, on any airplane if the relay has a date code between 0000 and 0343 and does not have an additional date code with the letter “T.”
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
