AD 2007-05-14 Airworthiness Directives; General Electric Company (GE) CF6-80C2 Turbofan Engines

This AD applies to the following General Electric Company (GE) turbofan engines with cast titanium assembly engine mount platforms part numbers (P/Ns) 1292M13G06, 1301M28G08, 1459M70G07, and 1846M24G04 and cast titanium assembly engine mount yokes P/Ns 9383M43G14 and 9383M43G16 installed. CF6-80C2A1 CF6-80C2A2 CF6-80C2A3 CF6-80C2A5 CF6-80C2A8 CF6-80C2A5F CF6-80C2B1 CF6-80C2B2 CF6-80C2B4 CF6-80C2B6 CF6-80C2B1F CF6-80C2B2F CF6-80C2B4F CF6-80C2B5F CF6-80C2B6F CF6-80C2B6FA CF6-80C2B7F CF6-80C2B8F CF6-80C2D1F These engines are installed on, but not limited to, Boeing 747, Boeing 767, MD-11 and Airbus A300-600 and A310 airplanes.

You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done. P/N and SN Weld-Repaired Forward Engine Mount Platforms and Forward Engine Mount Yokes Requiring Replacement (f) Table 1 of this AD lists the P/Ns and serial numbers (SNs) of the weld-repaired forward engine mount platforms that have a weld repair in a non-redundant area of the mount and must be replaced. Table 1.—Weld-Repaired Forward Engine Mount Platforms Requiring Replacement That Have a Weld Repair in a Non-Redundant Area of the Mount P/Ns SNs 1292M13G06 or 1846M24G04 WACHH228 WACHH254   WACHH285   WACHH290   WACHH292   WACHH295   WACHH299   WACHH384   WACHH427   WACHH440   WACHH604 1301M28G08 WACAR292   WACAR354 (g) Table 2 of this AD lists the P/Ns and SNs of the weld-repaired forward engine mount platforms that have a weld repair in a redundant area of the mount. Because it is impossible to detect whether the mount is operating on the redundant feature, each of these mounts must be replaced. The compliance time for mounts in this category can be longer than for the mounts listed in Table 1 of this AD. Table 2.—Weld-Repaired Forward Engine Mount Platforms Requiring Replacement That Have a Weld Repair in a Redundant Area of the Mount P/Ns SNs 1292M13G06 or 1846M24G04 WACHH173 WACHH189   WACHH274   WACHH278   WACHH314   WACHH325   WACHH486 1301M28G08 WACAR294   WACAR304   WACAR353   WACAR372 1459M70G07 MTXT1282 (h) Table 3 of this AD lists the P/Ns and SNs of the weld-repaired forward engine mount yokes that have a weld repair in a redundant area of the yoke. Because it is impossible to detect whether the mount yoke is operating on the redundant feature, each of these mount yokes must be replaced. The compliance time for mounts in this category can be longer than for the mounts listed in Table 1 of this AD. Table 3.—Weld-Repaired Forward Engine Mount Yokes Requiring Replacement That Have a Weld Repair in a Redundant Area of the Yoke P/Ns SNs 9383M43G14 WACV0388   WACV0394   WACV0405   WACV0406   WACV0477   WACV0498   WACV0529   WACV0556   WACV0579   WACV0581   WACV0582   WACV0600   WACV0605   WACV0617   WACV0625   WACV0627   WACV0633   WACV0645   WACV0683   WACV0703   WACV0733   WACV0737   WACV0759   WACV0775   WACV0791   WACV0799   WACV0875   WACV0883   WACV0885   WACV0909   WACV1097   WACV1615   WACV1713   WACV1753   WACV1797   WACV1867   WACV1987   WACV2131   WACV2159   WACV2185   WACV2343   WACV2511   WACV2695   WACV2707   WACV2881   WACV2899 9383M43G16 WACV0511   WACV0515   WACV0518   WACV0540   WACV0542   WACV0571   WACV0689   WACV0721   WACV0727   WACV0730   WACV0786   WACV0816   WACV0954 (i) GE advises that forward engine mount platform, P/Ns 1292M13G06 and 1846M24G04, are the same, except that P/N 1846M24G04 incorporates a previously approved field rework. This rework allows the thrust pin hole in the forward engine mount platform to be bored out to accept installation of an oversized thrust pin. GE cannot identify which SN goes with which P/N, but all SNs are affected. Welded Cast Titanium Forward Engine Mount Platform and Forward Engine Mount Yoke Removal (j) If the P/N and SN of the forward engine mount platform listed in Table 1 and Table 2 and the forward engine mount yoke listed in Table 3 of this AD are not installed on the engine, no further action is necessary. (k) If the P/N and SN of the forward engine mount platform listed in Table 1 of this AD is installed on the engine: (1) Remove the forward engine mount platform from the engine within 500 cycles or 6 months, after the effective date of this AD, whichever occurs first. (2) Information for removal of the forward engine mount platform from the engine can be found in the CF6-80C2 Engine Manual, 72-00-01, Disassembly. (l) If the P/N and SN of the forward engine mount platform listed in Table 2 of this AD is installed on the engine: (1) Remove the forward engine mount platform at the next shop visit, or within 4,800 cycles after the effective date of this AD, whichever occurs first. (2) Information for removal of the forward engine mount yoke can be found in the CF6-80C2 Engine Manual, 72-00-01, Disassembly. (m) If the P/N and SN of the forward engine mount yoke listed in Table 3 of this AD is installed on the engine: (1) Remove the forward engine mount yoke at the next shop visit, or within 4,800 cycles after the effective date of this AD, whichever occurs first. (2) Information for removal of the forward engine mount yoke can be found in the CF6-80C2 Engine Manual, 72-00-01, Disassembly. (n) Replace the affected forward engine mount platform and or the affected forward engine mount yoke with a non-weld-repaired cast titanium forward engine mount platform and or the forward engine mount yoke or a forged titanium forward engine mount platform or a forged titanium forward engine mount yoke. (o) Information for installing the forward engine mount platform and forward engine mount yoke can be found in the CF6-80C2 Engine Manual, 72-00-01, Assembly. (p) Location of the forward engine mount platform and forward engine mount yoke and SN are illustrated in the following Figure 1. BILLING CODE 4910-13-P ER05MR07.000 (q) After the effective date of this AD, do not install a weld-repaired, cast forward engine mount platform or a weld-repaired, cast forward engine mount yoke in any engine. Alternative Methods of

This AD results from the discovery of cracks in a forward engine mount platform and a forward engine mount yoke found during fluorescent penetrant inspection (FPI). We are issuing this AD to prevent cracks in the forward engine mount platform and forward engine mount yoke that could result in possible separation of the engine from the airplane.