Airworthiness directives: Allison Engine Co.,

[Federal Register: January 29, 1999 (Volume 64, Number 19)]

[Rules and Regulations]

[Page 4525-4526]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr29ja99-4]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-ANE-14-AD; Amendment 39-11017; AD 99-03-03]

RIN 2120-AA64

Airworthiness Directives; Allison Engine Company Model AE 3007A and AE 3007A1/1 Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

SUMMARY: This amendment supersedes an existing airworthiness directive (AD), applicable to Allison Engine Company Model AE 3007A turbofan engines, that currently requires reprogramming the Full Authority Digital Engine Control (FADEC) to software version VI.2. This amendment requires reprogramming the FADEC to a serviceable software version and reidentifying the FADEC assembly. This amendment is prompted by reports of at least seven uncommanded engine shutdowns, four of which occurred in flight, as a result of deficiencies in software version VI.2 on the AE 3007A engines and version VI.4 on the AE 3007A1/1 engines. The actions specified by this AD are intended to prevent an unintentional or uncommanded in-flight engine shutdown.

DATES: Effective February 16, 1999.

Comments for inclusion in the Rules Docket must be received on or before March 30, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 98-ANE-14-AD, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may also be sent via the Internet using the following address: ``9-ad- engineprop@faa.gov.'' Comments sent via the Internet must contain the docket number in the subject line.

FOR FURTHER INFORMATION CONTACT: Kyri Zaroyiannis, Aerospace Engineer, Chicago Aircraft Certification Office, FAA, Small Airplane Directorate, 2300 East Devon Avenue, Des Plaines, IL 60018; telephone (847) 294- 7836, fax (847) 294-7834.

SUPPLEMENTARY INFORMATION: On June 9, 1998, the Federal Aviation Administration (FAA) issued airworthiness directive (AD) 98-12-12, Amendment 39-10568 (63 FR 31338 June 9, 1998), to require programming the Full Authority Digital Engine Control (FADEC) with software version VI.2 (Allison Software part number 23068660; Allison FADEC assembly, with software VI.2 installed, part number 23068661). Additionally, the AD required that the FAA-approved Airplane Flight Manual be revised by incorporating the Embraer Flight Manual AFM 145/1153, Revision 14, dated May 7, 1998. These actions were prompted by reports of five in- flight engine shutdowns on Allison Engine Company AE 3007 series turbofan engines due to inadequate fault accommodation logic. That condition, if not corrected, could result in an unintentional or uncommanded in-flight engine shutdown.

Since the issuance of that AD, there have been at least seven uncommanded engine shutdowns, four of which occurred in flight, as a result of deficiencies in software version VI.2 on the AE 3007A engines and version VI.4 on the AE 3007A1/1 engines. Improved software version, VI.6A has been developed to address the deficiencies in software versions VI.2 and VI.4.

The compliance hourly schedule of this AD was chosen based on overall fleet risk assessment of a hazardous condition occurring, parts availability, and shop capacity. The compliance end date was chosen to further assure the desired level of safety of this action as affected by aircraft utilization variations throughout the fleet.

Since an unsafe condition has been identified that is likely to exist or develop on other Allison Engine Company AE 3007A and AE 3007A1/1 turbofan engines of the same type design, this AD supersedes AD 98-12-12 to require replacing FADEC

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assemblies, P/N 23062835, 23069253, 23068661, and 23068670 with serviceable parts.

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 filedin the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 98-ANE-14-AD.'' The postcard will be date stamped and returned to the commenter.

The regulations adopted herein will not have substantial direct effects 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. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

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, 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 removing Amendment 39-10568, (63 FR 31338, June 9, 1998), and by adding a new airworthiness directive, Amendment 39-11017, to read as follows:

   99-03-03 Allison Engine Company: Amendment 39-11017. Docket 98-ANE- 14-AD. Supersedes AD 98-12-12, Amendment 39-10568.

   Applicability: Allison Engine Company AE 3007A and AE 3007A1/1 turbofan engines. These engines are installed on, but not limited to the following airplanes: Embraer Model EMB-145, EMB-145ER, EMB- 145MR, and EMB-145LR.

   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 (d) 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.

   Compliance: Required as indicated, unless accomplished previously.

   To prevent an unintentional or uncommanded in-flight engine shutdown, accomplish the following:

   (a) Replace the Full Authority Digital Electronic Control (FADEC) assembly part numbers (P/N) 23062835, 23069253, 23068661, and 23068670, with serviceable parts within 200 flight hours after the effective date of this AD, but not later than April 30, 1999.

   (b) Prior to further flight, revise the FAA-approved Airplane Flight Manual by incorporating Embraer EMB-145 U.S. Airplane Flight Manual, Document No. AFM-145/1153, pages 3-14, 3-36B, 4-1, and 4-11, and 4-12 of Revision 14, dated May 7, 1998, until all affected engines within that operator's fleet are in compliance with this AD.

   (c) For the purpose of this AD, a serviceable part is any serviceable FADEC assembly except P/N's 23062835, 23069253, 23068661, or 23068670. This AD action eliminates FADEC assembly P/ N's 23062835, 23069253, 23068661, or 2306867 from installation eligibility and continued use in service.

   Note 2: Complete instructions for reprogramming and reidentifying the existing FADEC are contained in Rolls-Royce SB AE 3007A-73-021, Revision 1, dated December 23, 1998.

   (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 Manager, Chicago Aircraft Certification Office. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Chicago Aircraft Certification Office.

   Note 3: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Chicago Aircraft Certification Office.

   (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.

   (f) This amendment becomes effective on February 16, 1999.

   Issued in Burlington, Massachusetts, on January 25, 1999. David A. Downey, Assistant Manager, Engine and Propeller Directorate, Aircraft Certification Service.

   [FR Doc. 99-2151Filed1-28-99; 8:45 am]

   BILLING CODE 4910-13-U