Airworthiness Directive · Amendment 39-16808 · General Electric Company (GE) CT7-8, CT7-8A, CT7-8A1, CT7-8E, and CT7-8F5 Turboshaft Engines
General Electric Company (GE) CT7-8, CT7-8A, CT7-8A1, CT7-8E, and CT7-8F5 Turboshaft Engines
This AD applies to the following General Electric Company (GE) turboshaft engines:
(1) CT7-8, all engine serial numbers (S/Ns).
(2) CT7-8A, engine S/Ns 947565 and below.
(3) CT7-8A1, engine S/Ns 530017 and below.
(4) CT7-8E, engine S/Ns 953068 and below, and S/Ns 953070 through 953072.
(5) CT7-8F5, engine S/Ns 731005 and below, and S/Ns 731007, 731008, 817021, and 817022.
We are adopting a new airworthiness directive (AD) for the products listed above. This AD was prompted by four reports of unrecoverable engine stalls, during hover in a left-roll attitude. This AD requires the installation of an accessory gearbox (AGB) axis-A oil slinger nut to the axis-A shaft assembly. We are issuing this AD to prevent an unrecoverable engine stall, leading to a helicopter forced landing or accident.
Comply with this AD at the next engine shop visit, the next 1,500-hour helicopter inspection, or before operation after next engine installation, whichever occurs first.
Install the AGB axis-A oil slinger nut to the axis-A shaft assembly. Use Accomplishment Instructions, paragraphs 3.A. through 3.C. of GE Aircraft Engines CT7-8 Turboshaft Engine Service Bulletin No. CT7-8 S/B 72-0033, Revision 1, dated April 28, 2011, to do the installation.
An oil slinger nut installation performed before the effective date of this AD using GE Aircraft Engines CT7-8 Turboshaft Engine Service Bulletin No. CT7-8 S/B 72-0033, dated February 11, 2011, satisfies the installation requirements of this AD.
