Airworthiness Directive · Amendment 39-16987 · Fuel
The Boeing Company Airplanes
This AD applies to The Boeing Company Model 757-200, -200PF, -200CB, and -300 series airplanes, certificated in any category; as identified in the applicable service bulletin specified in paragraph (c)(1) or (c)(2) of this AD.
(1) For Model 757-200, -200PF, and -200CB series airplanes: Boeing Service Bulletin 757-28A0078, Revision 2, dated January 11, 2012.
(2) For Model 757-300 series airplanes: Boeing Service Bulletin 757-28A0079, Revision 2, dated January 11, 2012.
We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 757 airplanes. This AD requires replacing the power control relays for the fuel boost pumps and override pumps with new relays having a ground fault interrupter (GFI) feature. This AD also requires an electrical bonding resistance measurement for certain GFI relays to verify that certain bonding requirements are met. This AD also requires, for certain airplanes, an inspection to ensure that certain screws are properly installed, and installing longer screws if necessary. This AD was prompted by fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent damage to the fuel pumps caused by electrical arcing that could introduce an ignition source in the fuel tank, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.
For airplanes on which the actions specified in Boeing Alert Service Bulletin 757-28A0078, dated July 16, 2008, or 757-28A0079, dated July 16, 2008, have not been accomplished before the effective date of this AD: Within 60 months after the effective date of this AD, do the actions specified in paragraphs (g)(1) and (g)(2) of this AD.
(1) Replace the power control relays for the main tank fuel boost pumps with new relays having a ground fault interrupter (GFI) feature; do applicable electrical bonding resistance measurements between the GFI relays and their installation panel to verify that applicable bonding requirements are met; and do an operational test to ensure correct operation; as specified in Boeing Service Bulletin 757-28A0078, Revision 2, dated January 11, 2012 (for Model 757-200, -200CB, and -200PF series airplanes); or Boeing Service Bulletin 757-28A0079, Revision 2, dated January 11, 2012 (for Model 757-300 series airplanes). Do all actions in accordance with Part 1 of the Accomplishment Instructions of Boeing Service Bulletin 757-28A0078, Revision 2, dated January 11, 2012 (for Model 757-200, -200CB, and -200PF series airplanes); or Boeing Service Bulletin 757-28A0079, Revision 2, dated January 11, 2012 (for Model 757-300 series airplanes).
(2) Replace the power control relays for the center tank override fuel boost pumps with new relays having a GFI feature, in accordance with the actions required in paragraph (g)(2)(i) or (g)(2)(ii) of this AD.
(i) Replace the power control relays with new relays having a GFI feature; do applicable electrical bonding resistance measurements between the GFI relays and their installation panel to verify that applicable bonding requirements are met; and do an operational test to ensure correct operation; as specified in Boeing Service Bulletin 757-28A0078, Revision 2, dated January 11, 2012 (for Model 757-200, -200CB, and -200PF series airplanes); or Boeing Service Bulletin 757-28A0079, Revision 2, dated January 11, 2012 (for Model 757-300 series airplanes). Do all actions in accordance with Part 1 of the Accomplishment Instructions of Boeing Service Bulletin 757-28A0078, Revision 2, dated January 11, 2012 (for Model 757-200, -200CB, and -200PF series airplanes), or Boeing Service Bulletin 757-28A0079, Revision 2, dated January 11, 2012 (for Model 757-300 series airplanes).
(ii) Install and maintain TDG Aerospace universal fault interrupters (UFIs), in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA.
Note 1 to paragraph (g)(2)(ii) of this AD: Guidance on installing TDG Aerospace UFIs can be found in Supplemental Type Certificate ST01950LA (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgSTC.nsf/0/196ec7e864607b5b862573c5007cb3b5/$FILE/ST01950LA.pdf).
For airplanes on which the actions specified in Boeing Alert Service Bulletin 757-28A0078, dated July 16, 2008, or 757-28A0079, dated July 16, 2008, have been accomplished before the effective date of this AD: Within 60 months after the effective date of this AD, do a general visual inspection to verify that each GFI installation screw has enough grip length to hold the screws in each nut plate, and do applicable electrical bonding resistance measurements between the GFI relays and their installation panel to verify that applicable bonding requirements are met. If the screw does not have enough grip length, before further flight, install a longer screw. Do all actions in accordance with Part 2 of the Accomplishment Instructions of Boeing Service Bulletin 757-28A0078, Revision 2, dated January 11, 2012 (for Model 757-200, -200CB, and -200PF series airplanes); or Boeing Service Bulletin 757-28A0079, Revision 2, dated January 11, 2012 (for Model 757-300 series airplanes).
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
