Airworthiness Directive · Amendment 39-11763 · Honeywell International Inc. (Formerly AlliedSignal Inc.) ALF502R and LF507 Series Turbofan Engines
Honeywell International Inc. (Formerly AlliedSignal Inc.) ALF502R and LF507 Series Turbofan Engines
Honeywell International Inc. (formerly AlliedSignal, Textron Lycoming and Avco Lycoming) ALF502R and LF507 series turbofan engines, installed on but not limited to British Aerospace BAe 146-100A, BAe 146-200A, BAe 146-300A, AVRO 146-RJ70A, AVRO 146-RJ85A, and AVRO 146-100A series airplanes.
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 Chapter 5, Airworthiness Limitations section, of the Honeywell International Inc. ALF502R and LF507 series Engine Manuals to include required enhanced inspection of selected critical life-limited parts at each piece-part exposure. This action requires an air carrier's approved continuous airworthiness maintenance program to incorporate these inspection procedures. This action 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 60 days after the effective date of this AD, revise Chapter 5, Airworthiness Limitations section, of the Honeywell International Inc. ALF502R and LF507 Engine Manuals, and the appropriate manuals of former type certificate holders of the engine design including: Allied Signal Inc.; Textron Lycoming, Stratford Division; Avco Lycoming, Stratford Division and Avco Lycoming Engine Group, Stratford Division, Connecticut, and for air carrier operations revise the approved continuous airworthiness maintenance program, by adding the following:
“Chapter 5, Airworthiness Limitations Section, Mandatory Inspections:
(1) Perform inspections of the following parts at each piece-part opportunity in accordance with the instructions provided in the applicable manual provisions:
| Part nomenclature | Part number (P/N) | Inspect per engine manual chapter |
|---|---|---|
| For ALF502R series turbofan engines: | ||
| Fan Disc | All | 72-31-07 Inspection/Check. |
| First Turbine Disc | All | 72-51-12 Inspection/Check. |
| Second Turbine Disc | All | 72-51-21 Inspection/Check. |
| Impeller | All | 72-34-38 Inspection/Check. |
| LPT Shaft/3rd Turbine | All | 72-52-03 Inspection/Check. |
| Fourth Turbine Disc | All | 72-52-06 Inspection/Check. |
| For LF507 series turbofan engines: | ||
| Fan Disc | All | 72-31-08 Inspection/Check. |
| First Turbine Disc | All | 72-51-11 Inspection/Check. |
| Second Turbine Disc | All | 72-51-20 Inspection/Check. |
| Impeller | All | 72-34-20 Inspection/Check. |
| LPT Shaft/3rd Turbine | All | 72-52-24 Inspection/Check. |
| Fourth Turbine Disc | All | 72-52-03 Inspection/Check. |
(2) For the purposes of these mandatory inspections, piece-part opportunity means:
(i) The part is completely disassembled when done in accordance with the disassembly instructions in the engine manufacturer's Engine Manual; and
(ii) 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.”
(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 Chapter 5, Airworthiness Limitations section, of the Honeywell International Inc. ALF502R and LF507 Engine Manuals.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Engines
