Airworthiness Directive · Amendment 39-14030 · General Electric Company CF34-8C1 Series and CF34-8C5 Series Turbofan Engines
General Electric Company CF34-8C1 Series and CF34-8C5 Series Turbofan Engines
This AD applies to General Electric Company (GE) CF34-8C1 series and CF34-8C5 series turbofan engines, with master variable geometry (VG) actuators, GE part number 4120T02P02, serial number (SN) APM238AE, and SNs APM242AE and up; and Arkwin Industries, Inc. Parts Manufacturer Approval (PMA) part number 1211508-002, SN 238AE and SNs 242AE and up installed. The Arkwin PMA parts are also marked with PN 4120T02P02. These engines are installed on, but not limited to, Bombardier Inc. Model CL-600-2C10 (CRJ-700 & -701) and CL-600-2D24 (CRJ-900) airplanes.
The FAA is superseding an existing airworthiness directive (AD) for General Electric Company (GE) CF34-8C1 series and CF34-8C5 series turbofan engines, with certain serial number (SN) master variable geometry (VG) actuators installed. That AD currently requires initial and repetitive reviews of the airplane Maintenance Data Computer (MDC) for master VG actuator fault messages, and if the MDC is inoperative, reviews of the Engine Indication and Crew Alerting System (EICAS) for fault messages. That AD also requires replacing actuators reported faulty by the Full Authority Digital Engine Control (FADEC). This ad requires those same actions, and expands the applicability to additional actuators by part number (P/N) and SN. This AD also prohibits installation of affected master VG actuators onto any CF34- 8C1 and CF34-8C5 engine after the effective date of this AD. This AD results from the need to add to the list of affected parts, master VG actuators made by parts manufacturer approval (PMA). We are issuing this AD to prevent dual-channel electrical signal faults in the VG master actuator, which will cause an uncommanded reduction of thrust to idle with a subsequent loss of the ability to advance thrust above idle, and which will result in a multiengine loss of thrust if dual- channel faults occur on more than one engine simultaneously.
You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.
(f) After the effective date of this AD, do not install any master VG actuators specified in this AD onto any engine.
Within 10 days after the effective date of this AD, initially review the Maintenance Data Computer (MDC) fault history, and if the MDC is inoperative, review the Engine Indication and Crew Alerting System (EICAS) for fault messages, and replace actuators with faults reported by the FADEC. Follow the review and replacement requirements of paragraph 3 of the Accomplishment Instructions of GE Alert Service Bulletin (ASB) No. CF34-8C-AL S/B 75-A0007, Revision 3, dated February 14, 2005.
At intervals not to exceed 10 days, repetitively review the MDC fault history, and if the MDC is inoperative, review the EICAS for fault messages, and replace actuators with faults reported by the FADEC. Follow the review and replacement requirements of paragraph 3 of the Accomplishment Instructions of GE ASB No. CF34-8C-AL S/B 75-A0007, Revision 3, dated February 14, 2005.
(i) Replacing an affected master VG Actuator with a master VG actuator not specified in this AD is terminating action for the repetitive inspections requirement specified in paragraph (h) of this AD for that actuator.
Inspections completed before the effective date of this AD using GE ASB No. CF34-8C-AL S/B 75-A0007, Revision 1 dated November 7, 2003; or Revision 2 dated December 16, 2004; or Revision 3 dated February 14, 2005; are acceptable for compliance with the corresponding inspection in this AD.
