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2009-07-12: High-pressure (HP)

FAA order 2009-07-12 is an airworthiness directive in force since May 7, 2009. The FAA's subject line: High-pressure (HP). It names the General Electric CF-34-1A, General Electric CF34-3A, General Electric CF34-3A1, General Electric CF34-3A2, General Electric CF34-3B, General Electric CF34-3B1 engines: about 484 aircraft on the U.S. register today across them, though an order usually covers particular versions or serial numbers rather than every one. System: engine.

What it applies to as the FAA lists it

Kind of product
Engine
Makes
General Electric Aircraft Engines
Models
CF34-1A, CF34-3A, CF34-3A1, CF34-3A2, CF34-3B, CF34-3B1
Engine series
General Electric CF-34-1A 13 aircraft
General Electric CF34-3A 15 aircraft
General Electric CF34-3A1 15 aircraft
General Electric CF34-3A2 20 aircraft
General Electric CF34-3B 327 aircraft
General Electric CF34-3B1 94 aircraft

Dates and paperwork

In force since
May 7, 2009
Published
April 2, 2009 (signed March 26, 2009)
Docket
FAA-2007-0419
Status
Current
The FAA's document
Read the order on the FAA's site

The FAA's summary their words, unchanged

The FAA is adopting a new airworthiness directive (AD) for General Electric Company (GE) CF34-1A, -3A, -3A1, -3A2, -3B, and -3B1 turbofan engines with high-pressure (HP) rotor 4-step air balance piston stationary seals (4-step seals), part numbers (P/Ns) 4923T54G01, 6019T90G03, 6037T99G01, 6037T99G02, and 6037T99G03, installed. This AD requires removing the 4-step seals and incorporating an 8-step seal at the next piece-part exposure. This AD results from the investigation of an airplane accident. Both engines experienced high-altitude flameout. Rotation of the HP rotors was not maintained during descent and the engines could not be restarted. We are issuing this AD to prevent the inability to restart both engines after flameout due to excessive friction of the 4-step seal, which could result in subsequent forced landing of the airplane.

The order itself the regulatory text, as published

Show the full text (2,552 characters)
2009-07-12 General Electric Company: Amendment 39-15871. Docket No. FAA-2007-0419; Directorate Identifier 2007-NE-52-AD. Effective Date (a) This airworthiness directive (AD) becomes effective May 7, 2009. Affected ADs (b) None. Applicability (c) This AD applies to General Electric Company (GE) CF34-1A, - 3A, -3A1, -3A2, -3B, and -3B1 turbofan engines, with high-pressure (HP) rotor 4-step air balance piston stationary seals (4-step seals), part numbers (P/Ns) 4923T54G01, 6019T90G03, 6037T99G01, 6037T99G02, and 6037T99G03, installed. These engines are installed on, but not limited to, Bombardier, Inc. airplane models CL-600- 2A12, -2B16, and -2B19. Unsafe Condition (d) This AD results from the investigation of an airplane accident. Both engines experienced high-power flameout. Rotation of the HP rotors was not maintained during descent and the engines could not be restarted. We are issuing this AD to prevent the inability to restart both engines after flameout due to excessive friction of the 4-step seal, which could result in subsequent forced landing of the airplane. Compliance (e) You are responsible for having the actions required by this AD performed at the next piece-part exposure after the effective date of this AD, unless the actions have already been done. (f) Remove the 4-step seals, P/Ns 4923T54G01, 6019T90G03, 6037T99G01, 6037T99G02, and 6037T99G03. (g) Incorporate an 8-step seal, either by modifying the existing 4-step seal to an 8-step seal, or by replacing it with an 8-step seal. (h) Information on modifying the seal and part number configuration charts, can be found in GE Service Bulletin (SB) No. CF34-AL S/B 72-0238, dated July 27, 2007 (CL-600-2B19), and SB No. CF34-BJ S/B 72-0217, dated July 27, 2007 (CL-600-2A12 and CL-600- 2B16). Definition (i) For the purposes of this AD, piece-part exposure means when the 4-step seal is removed from the engine or when the combustion liner is removed. Alternative Methods of Compliance (j) The Manager, Engine Certification Office, has the authority to approve alternative methods of compliance for this AD if requested using the procedures found in 14 CFR 39.19. Related Information (k) Contact Kenneth Steeves, Aerospace Engineer, Engine Certification Office, Engine and Propeller Directorate, FAA, 12 New England Executive Park, Burlington, MA 01803; e-mail: keneth.steeves@faa.gov; telephone: (781) 238-7765, fax: (781) 238- 7199, for more information about this AD. Material Incorporated by Reference (l) None.

Source: FAA Dynamic Regulatory System, airworthiness directives. The FAA's document is the authority; the register counts are this site's, from the FAA register of October 5, 2026. Connections as data: /graph/directive/2009-07-12.json · aircraft systems.