Airworthiness Directive · Amendment 39-17438 · General Electric Company Turbofan Engines
General Electric Company Turbofan Engines
This AD applies to all General Electric Company (GE) CF6-80C2 A1/A2/A3/A5/A8/A5F/B1/B2/B4/B5F/B6/B1F/B2F/B4F/B6F/B7F/D1F turbofan engines with any of the following installed:
(1) Fuel tube, part number (P/N) 1321M42G01, 1334M88G01, 1374M30G01, or 1383M12G01.
(2) Spray shield, P/N 1606M57G01, 1606M57G03, or 1775M61G01.
(3) Supporting bracket, P/N 1321M88P001A.
We are superseding an existing airworthiness directive (AD) for certain General Electric Company (GE) CF6-80C2 series turbofan engines. That AD currently requires replacement of the fuel tube connecting the flowmeter to the integrated drive generator (IDG) fuel- oil cooler and the fuel tube(s) connecting the main engine control (MEC) or hydromechanical (HMU) to the flowmeter, with improved fuel tubes. This new AD requires the same actions, requires installation of a new simplified one-piece supporting bracket, adds an engine model, alters the list of affected part numbers (P/Ns), changes the replacement schedule, and revises our estimated cost of compliance. This AD was prompted by several additional reports of fuel leaks and two reports of engine fire due to improper assembly of supporting brackets on the fuel tube connecting the flowmeter to the IDG fuel-oil cooler. We are issuing this AD to prevent high-pressure fuel leaks caused by improper seating of fuel tube flanges, which could result in an engine fire and damage to the airplane.
After the effective date of this AD, if the fuel tubes are disconnected for any reason, or at the next engine shop visit, whichever occurs first, replace the fuel tubes and brackets with improved tubes and brackets eligible for installation. For on-wing maintenance, replace only tubes and brackets that have been disconnected. Do the following:
(1) Replace the fuel flowmeter to IDG fuel-oil cooler fuel tube, P/N 1321M42G01, with a part eligible for installation.
(2) For engines with Power Management Controls, replace the main engine control to fuel flowmeter fuel tube, P/N 1334M88G01, with a part eligible for installation.
(3) For engines with full authority digital electronic controls, replace the hydromechanical unit to fuel flowmeter fuel tubes, P/Ns 1383M12G01 and 1374M30G01, with a part eligible for installation.
(4) Replace supporting bracket, P/N 1321M88P001A, and spray shields, P/Ns 1606M57G01, 1606M57G03, and 1775M61G01 with one-piece supporting bracket, P/N 2021M83G01.
(5) Perform an idle leak check after accomplishing paragraphs (f)(1), (f)(2), (f)(3), or (f)(4), or any combination thereof.
After the effective date of this AD, do not install any of the following parts into any GE CF6-80C2 series turbofan engines: fuel tubes P/Ns 1321M42G01, 1334M88G01, 1374M30G01, and 1383M12G01, supporting bracket P/N 1321M88P001A, and spray shields P/Ns 1606M57G01, 1606M57G03, and 1775M61G01.
For the purpose of this AD, an engine shop visit is the induction of an engine into the shop for maintenance involving separation of pairs of major mating engine flanges (lettered flanges), except that the separation of engine flanges solely for the purposes of transporting the engine without subsequent engine maintenance does not constitute an engine shop visit.
