Airworthiness Directive · Amendment 39-14241 · General Electric Company CT7-5, -7, and -9 Series Turboprop Engines
General Electric Company CT7-5, -7, and -9 Series Turboprop Engines
Superseded. A later AD replaced this one: AD 2007-08-01. Comply with the one in force.
This AD applies to General Electric Company (GE) CT7-5A2, -5A3, -7A, -7A1, -9B, -9B1, and -9B2 turboprop engines, with stage 2 turbine aft cooling plate, part number (P/N) 6064T07P01, 6064T07P02, 6064T07P05, or 6068T36P01 installed. These engines are installed on, but not limited to, Construcciones Aeronauticas, SA CN-235 series and SAAB Aircraft AB SF340 series airplanes.
The FAA is adopting a new airworthiness directive (AD) for General Electric Company (GE) CT7-5A2, -5A3, -7A, -7A1, -9B, -9B1, and -9B2 turboprop engines, with stage 2 turbine aft cooling plate, part number (P/N) 6064T07P01, 6064T07P02, 6064T07P05, or 6068T36P01 installed. This AD requires a onetime eddy current inspection (ECI) of certain P/N stage 2 turbine aft cooling plate boltholes. This AD results from reports of six stage 2 turbine aft cooling plates found cracked during inspection. We are issuing this AD to prevent stage 2 aft cooling plate separation, resulting in uncontained engine failure and damage to the airplane.
You are responsible for having the actions required by this AD performed at the next engine or hot section module shop visit, but before accumulating an additional 6,000 cycles-in-service after the effective date of the AD, unless already done.
Perform a onetime ECI of the stage 2 turbine aft cooling plate boltholes, using paragraph 3.B. of GE Alert Service Bulletin (ASB) No. CT7-TP S/B 72-A0464, Revision 2, dated May 9, 2003.
(g) Remove from service any stage 2 turbine aft cooling plate that does not pass the return to service criteria specified in paragraph 3.B.(2) of GE Alert Service Bulletin (ASB) No. CT7-TP S/B 72-A0464, Revision 2, dated May 9, 2003.
Previous credit is allowed for onetime ECIs of the stage 2 turbine aft cooling plate boltholes that were done using GE ASB No. CT7-TP S/B 72-A0464, dated February 25, 2003, or GE ASB No. CT7-TP S/B 72-A0464, Revision 1, dated March 12, 2003, before the effective date of this AD.
(i) For the purposes of this AD, an engine or hot section module shop visit is defined as the introduction of the engine or hot section module into a shop that includes separation of CT7 turboprop engine major case flanges.
