Airworthiness Directive · Amendment 39-11422 · General Electric Aircraft Engines Engines
General Electric Aircraft Engines Engines
This AD applies to General Electric Aircraft Engines CF34-1A, CF34-3A, CF34-3A1, CF34-3A2, CF34-3B, CF34-3B1.
The models as the FAA's AD index lists them. The serial ranges, installed parts and exceptions are in the AD itself: read it at the FAA.
This amendment supersedes an existing airworthiness directive (AD), applicable to General Electric Aircraft Engines (GE) CF34 series turbofan engines, that currently requires installation of a main fuel control (MFC) that incorporates a flange vent groove and installation of an MFC with improved overspeed protection. This amendment requires replacement of Buna-N O-rings with Viton O-rings or a new location of the vent groove on the MFC mounting flange, or installation of an MFC with improved overspeed protection. This amendment is prompted by the determination that the location of the reworked vent groove was ineffective, and that replacement of Buna-N preformed packings with Viton preformed packings will alleviate the unsafe condition. The actions specified by this AD are intended to prevent uncommanded engine accelerations, which could result in an engine overspeed, uncontained engine failure, and damage to the airplane. The incorporation by reference of GE Alert ServiceBulletins (ASB s) No. A73-33, dated November 21, 1997; A73-33, Revision 1, dated May 29.1998; and A73-19, Revision 1, dated February 20, 1998, was approved by the Director of the Federal Register as of July 27, 1999. The incorporation by reference of GE ASB No. CF34AL 73-A0025, dated July 7, 1999; CF34BJ 73-A0040, dated July 7, 1999; CF34AL S/B 73-0026, dated August 12, 1999; and CF34BJ S/B 73-0041, dated August 12,1999, is approved by the Director of the Federal Register as of December 6, 1999. Comments for inclusion in the Rules Docket must be received on or before January 18, 2000.
