Airworthiness Directive · Amendment 39-11560 · General Electric Company CF34 Series Turbofan Engines
General Electric Company CF34 Series Turbofan Engines
General Electric Company (GE) CF34-3A1 and -3B1 series turbofan engines, installed on but not limited to Bombardier Canadair CL601R (RJ) aircraft.
Note 1: This airworthiness directive (AD) applies to each engine identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For engines that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (c) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.
This amendment adopts a new airworthiness directive (AD), that requires revisions to the Engine Maintenance Program specified in the manufacturer's Instructions for Continued Airworthiness (ICA) for General Electric Company (GE) CF34 series turbofan engines to include required enhanced inspection of selected critical life-limited parts at each piece-part exposure. This AD also requires that an air carrier's approved continuous airworthiness maintenance program incorporate these inspection procedures. This amendment is prompted by a Federal Aviation Administration (FAA) study of in-service events involving uncontained failures of critical rotating engine parts that indicated the need for improved inspections. The improved inspections are needed to identify those critical rotating parts with conditions, which if allowed to continue in service, could result in uncontained failures. The actions specified by this AD are intended to prevent critical life-limited rotating engine part failure, which could result in an uncontained engine failure and damage to the airplane.
To prevent critical life-limited rotating engine part failure, which could result in an uncontained engine failure and damage to the airplane, accomplish the following:
(a) Within the next 30 days after the effective date of this AD, revise the CF34 Engine Maintenance Program, Chapter 5-21-00, of the GE CF34 Series Turbofan Engine Manual, SEI-756, and for air carrier operations revise the approved continuous airworthiness maintenance program, by adding the following:
“9. CF34-3A1 and CF34-3B1 Engine Maintenance Program—Shop Level Mandatory Inspection Requirements.
A. This procedure is used to identify specific piece-parts that require mandatory inspections that must be accomplished at each piece-part exposure using the applicable Chapters referenced in Table 804 for the inspection requirements.
B. Piece-part exposure is defined as follows:
(1) For engines that utilize the “On Condition” maintenance requirements:
The part is considered completely disassembled when done in accordance with the disassembly instructions in the GEAE engine authorized overhaul Engine Manual, and the part has accumulated more than 100 cycles-in-service since the last piece-part opportunity inspection, provided that the part was not damaged or related to the cause for its removal from the engine.
(2) For engines that utilize the “Hard Time” maintenance requirements: The part is considered completely disassembled when done in accordance with the disassembly instructions used in the “Minor Maintenance” or “Overhaul” instructions in the GEAE engine authorized Engine Manual, and the part has accumulated more than 100 cycles in service since the last piece-part opportunity inspection, provided that the part was not damaged or related to the cause for its removal from the engine.
C. Refer to Table 804 below for the mandatory inspection requirements.
| Part nomenclature | Manual chapter/section/subject | Mandatory inspection |
|---|---|---|
| Fan Disk (all) | 72-21-00, Inspection | All areas (FPI) 1 Bores (ECI) 2 |
| Stage 1 high pressure turbine (HPT) Rotor Disk (all) | 72-46-00, Inspection | All areas (FPI) 1 Bores (ECI) 2 Boltholes (ECI) 2 Air Holes (ECI) 2 |
| Stage 2 HPT Rotor Disk (all) | 72-46-00, Inspection | All areas (FPI) 1 Bores (ECI) 2 Boltholes (ECI) 2 Air Holes (ECI) 2 |
| HPT Rotor Outer Torque Coupling (all) | 72-46-00, Inspection | All areas (FPI) 1 Bore (ECI) 1 |
(b) Except as provided in paragraph (c) of this AD, and notwithstanding contrary provisions in section 43.16 of the Federal Aviation Regulations (14 CFR 43.16), these mandatory inspections shall be performed only in accordance with the CF34 Engine Maintenance Program, Chapter 5-21-00, of the General Electric Company, CF34 Series Turbofan Engine Manual, SEI-756.
