Airworthiness Directive · Amendment 39-16492 · Fuel
The Boeing Company Model 757 and 767 Airplanes
This AD applies to The Boeing Company Model 757-200, 200CB, -200PF, and -300 series airplanes, line numbers 1 through 1050 inclusive, and all Model 767-200, -300, -300F, and -400ER series airplanes; certificated in any category.
We are adopting a new airworthiness directive (AD) for the products listed above. This AD requires repetitive testing for correct functioning of the engine indication and crew alerting system (EICAS) to ensure that it receives both the LOW FUEL and FUEL CONFIG discrete signals from the fuel quantity processor unit, and alerts the flightcrew of a low fuel situation, and if the test fails, troubleshooting to find wire faults and damaged equipment, and corrective actions if necessary. This AD was prompted by a report that the EICAS failed to alert the flightcrew of an improper fuel system configuration during flight. Later in that flight, the EICAS failed to alert the flightcrew that the fuel in the left- and right-hand main tanks was depleted below the minimum of 2,200 pounds. We are issuing this AD to detect and correct a single latent failure of the FUEL CONFIG discrete signal, which disables both the FUEL CONFIG and LOW FUEL messages. Such failure, combined with a flightcrew error in configuring the fuel system, could lead to depletion of the fuel in the main tanks and possible flame out of both engines. A dual engine flame out could result in inaccessibility of the remaining fuel in the center tank due to loss of electrical power to the pumps, consequent unrecoverable dual engine shutdown, and forced landing of the airplane.
Comply with this AD within the compliance times specified, unless already done.
Within 100 flight hours after the effective date of this AD: Do a test for correct functioning of the EICAS to ensure that it receives both the LOW FUEL and FUEL CONFIG discrete signals from the fuel quantity processor unit, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 757-28-0121, dated August 18, 2010; or Boeing Special Attention Service Bulletin 767-28-0106, dated August 25, 2010; as applicable. Repeat the test thereafter at intervals not to exceed 100 flight hours.
If any test required by paragraph (g) of this AD fails, before further flight, troubleshoot to find any wire faults, and damaged equipment (including bent connector pins), in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 757-28-0121, dated August 18, 2010; or Boeing Special Attention Service Bulletin 767-28-0106, dated August 25, 2010; as applicable.
(i) If, during any troubleshooting required by paragraph (h) of this AD, any wire fault or damaged equipment (including bent connector pins) is found, before further flight, do the applicable actions specified in paragraph (i)(1) or (i)(2) of this AD.
(1) For airplanes identified in Boeing Special Attention Service Bulletin 757-28-0121, dated August 18, 2010: Repair or replace affected wires and equipment (including bent connector pins), in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 757-28-0121, dated August 18, 2010.
(2) For airplanes identified in Boeing Special Attention Service Bulletin 767-28-0106, dated August 25, 2010: Do corrective actions using a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA.
Note 1: Guidance on doing corrective actions can be found in Chapter 28, Subject 28-41-00, Section July, of the Boeing 767 Fault Isolation Manual (FIM).
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.
Aircraft
