AD 2001-19-02

This amendment adopts a new airworthiness directive (AD) that is applicable to GE CF34-3A1, -3B, and -3B1 turbofan engines with scavenge screens part numbers (P/N's) 4047T95P01 and 5054T86G02 installed in the B-sump oil scavenge system. This action requires initial and repetitive visual inspections and cleaning of the B-sump scavenge screens. This amendment is prompted by five reports of B-sump oil scavenge system failure causing engine in-flight shutdowns. The actions specified in this AD are intended to prevent B-sump scavenge screen blockage due to coking, which could result in ignition of B-sump oil in the secondary air system, fan drive shaft separation, and uncontained engine failure.

Final rule; request for comments

2001-19-02-AD General Electric Company: Amendment 39-12441. Docket 2001-NE-21-AD.

Applicability

This airworthiness directive (AD) is applicable to General Electric Company (GE) CF34-3A1, -3B, and -3B1 turbofan engines with scavenge screens part numbers (P/N's) 4047T95P01 and 5054T86G02 installed in the B-sump oil scavenge system. These engines are installed on, but not limited to, Bombardier Inc. (Canadair) Model CL-600-2A12, CL-600-2B16, and CL-600-2B19 airplanes.

Note 1: This 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(d) of this AD. The request should include an assessment of the effectof the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the requests should include specific proposed actions to address it.

Compliance

Compliance with this AD is required as indicated, unless already done.

To prevent B-sump scavenge screen blockage due to coking, which could result in ignition of B-sump oil in the secondary air system, fan drive shaft separation, and uncontained engine failure, do the following:

Initial Inspection and Cleaning of B-Sump Screens

(a) Perform an initial visual inspection and cleaning of scavenge screens, P/N's 4047T95P01 and 5054T86G02, installed in the B-sump oil scavenge system, in accordance with Accomplishment Instructions Paragraphs 3A through 3B of GE Aircraft Engines (GEAE) Alert Service Bulletins (ASB's) CF34-AL 79-A0014, Revision 1, dated August 23, 2001, and ASB CF34-BJ 79-A0015, Revision 1, dated August 23, 2001 and the following table:

Initial Inspection and Cleaning Schedule

Engine hours time-since-new (TSN)
Inspect and clean
(1) Fewer than 4,000 hours time-since-new (TSN) or time-since-last-shop-visit (TSLSV).
Before 4,000 hours TSN or TSLSV.
(2) 4,000 to 8,000 hours TSN or TSLSV.
Within 500 hours time-in-service (TIS) after the effective date of this AD.
(3) 8,000 hours or greater TSN or TSLSV.
Within 100 hours TIS after the effective date of this AD.

Definition

(b) For the purposes of this Ad, a shop visit is defined as a shop visit during which the B-sump scavenge screens were cleaned, and the B-sump was removed from the engine and cleaned.

Repetitive Inspections and Cleaning

(c) Perform repetitive visual inspections and cleaning for scavenge screens, P/N's 4047T95P01 and 5054T86G02, installed in the B-sump oil scavenge system, in accordance with Accomplishment Instructions Paragraph 3A through 3B of GE Aircraft Engines (GEAE) Alert Service Bulletins (ASB's) CF34-AL 79-A0014, Revision 1, dated August 23, 2001, and ASB CF34-BJ 79-A0015, Revision 1, dated August 23, 2001, and the following:

(1) At intervals not to exceed 500 hours TIS if no coke is found in screens during initial or repetitive inspections, and

(2) At intervals not to exceed 100 hours TIS if coke is found in screens during initial or repetitive inspections.

Alternative Methods of Compliance

(d) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manger, Engine Certification Office (ECO). Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, ECO.

Note 2: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the ECO.

(e) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the aircraft to a location where the requirements of this AD can be accomplished.

Documents That Have Been Incorporated by Reference

(f) The inspections must be done in accordance with the following GE Aircraft Engines Alert Service Bulletins (ASB's):

Document No.
Pages
Revision
Date
ASB CF34-AL S/B 79-A0014
Total pages: 9
All
1
August 23, 2001.
ASB CF34-BJ S/B 79-A0015
Total pages: 9
All
1
August 23, 2001.

This incorporation by reference were approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from GE Aircraft Engines 1000 Western Avenue, Lynn, MA 01910; Attention: CF34 Product Support Engineering, Mail Zone: 34017; telephone (781) 594-6323; fax (781) 594-0600. Copies may be inspected at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street, NW, suite 700, Washington, DC.

Effective Date of This AD

(g) This amendment becomes effective on October 9, 2001.

The FAA recently received reports of five in-flight shutdowns of CF34-3A1, -3B, and -3B1 engines, due to inadequate B-sump oil scavenging and subsequent oil release from the B-sump into the secondary air system. Four of these engines experienced internal fire due to oil ignition in the secondary air system; two of these engines experienced fan drive shaft separation due to heat distress; and one engine experienced an uncontained engine failure. The manufacturer has determined that the cause of inadequate B-sump oil scavenging in B-sump scavenge screen blockage due to deposits of coke. The manufacturers believes that the coke build up on the screens is the result of hot soak-back temperatures in the B-sump after each engine shutdown. Coke build up is causing scavenge screen blockage which can prevent the lube and scavenge oil pump fro effectively scavenging the oil from the B-sump during engine operation. Unscavanged oil accumulates in the B-sump, escapes across the carbon seal, and ignites in the secondary air system. This condition, if not corrected, could result in ignition of B-sump oil in the secondary air system, fan drive shaft separation, and uncontained engine failure.

Manufacturer's Service Information

The FAA has reviewed and approved the technical contents of GE Aircraft Engines (GEAE) Alert Service Bulletins (ASB's) CF34-AL, 79-A0014, Revision 1, dated August 23, 2001, and ASB CF34-BJ 79-A0015, Revision 1, dated August 23, 2001, that describe procedures for initial and repetitive visual inspections and cleaning of the B-sump scavenge screens.

FAA's Determination of an Unsafe Condition and Proposed Actions

Since an unsafe condition has been identified that is likely to exist or develop on other GE CF34-3A1, -3B, and -3B1 turbofan engines of the same type design, this AD is being issued to prevent B-sump scavenge screen blockage due to coking, which could result in ignition of B-sump oil in the secondary air system, fan drive shaft separation, and uncontained engine failure. This AD requires initial and repetitive visual inspections and cleaning of scavenge screens P/N's 4047T95P01 and 5054T86G02, installed in the B-sump oil scavenge system.

Immediate Adoption of This AD

Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days.

Comments Invited

Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified under the caption ADDRESSES. All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 2001-NE-21-AD." The postcard will be date stamped and returned to the commenter.

Regulatory Analysis

This final rule does not have federalism implications, as defined in Executive Order 13132, because it would not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. Accordingly, the FAA has not consulted with state authorities prior to publication of this final rule.

The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39--AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive: