Airworthiness directives: Royce GmbH,

[Federal Register: August 17, 1999 (Volume 64, Number 158)]

[Proposed Rules]

[Page 44666-44667]

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

[DOCID:fr17au99-14]

[[Page 44666]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-ANE-74-AD]

Airworthiness Directives; BMW Rolls-Royce GmbH Models BR700- 710A1-10 and BR700-710A2-20 Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

SUMMARY: This document proposes to revise an existing airworthiness directive (AD) applicable to BMW Rolls-Royce GmbH (BRR) Models BR700- 710A1-10 and BR700-710A2-20 turbofan engines. The existing AD currently requires initial and repetitive visual inspections of the engine compressor and combustion core fairings (also referred to as the engine core fairings) and fasteners for correct installation and damage, and verification that the engine core fairing fasteners are torqued to a higher torque value. This action would increase the repetitive inspection interval to 150 hours time-in-service (TIS) following an initial inspection and follow-on inspection at the current 50 hours TIS interval. This action also would require an initial inspection and follow-on inspection at a 50 hours TIS interval following any engine core fairing or fastener removal, repair, or replacement. Repair of engine core fairings has been added as an alternate to engine core fairing replacement, and an inspection for loose engine core fairing(s) has been included to verify correct installation on the engine. This proposal is prompted by results of repetitive inspections that indicate that the inspection interval can be increased safely. The actions specified by the proposed AD are intended to prevent engine compressor or combustion core fairing detachment and damage to the engine bypass duct, resulting in engine failure and damage to the airplane.

DATES: Comments must be received by September 16, 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-74-AD, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may also be sent via the Internet using the following address: ``9-ane- adcomment@faa.gov''. Comments sent via the Internet must contain the docket number in the subject line. Comments may be inspected at this location between 8:00 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays.

The service information referenced in the proposed rule may be obtained from BMW Rolls-Royce GmbH, Eschenweg 11, D-15827 Dahlewitz, Germany; telephone 011-49-33-7086-1883; fax 011-49-33-7086-3276. This information may be examined at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Keith Mead, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (781) 238- 7744, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed 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 above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with the substance of this proposal 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-74-AD.'' The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 98-ANE-74-AD, 12 New England Executive Park, Burlington, MA 01803-5299.

Discussion

On February 16, 1999, the Federal Aviation Administration (FAA) issued airworthiness directive (AD) 98-24-03, Amendment 39-11050 (64 FR 9056, February 24, 1999), following a priority letter AD issued November 12, 1998, applicable to BMW Rolls-Royce GmbH (BRR) Models BR700-710A1-10 and BR700-710A2-20 turbofan engines. That AD requires initial and repetitive visual inspections of the engine compressor and combustion core fairings (also referred to as the engine core fairings) and fasteners for correct installation and damage, and verification that the engine core fairing fasteners are torqued to the higher torque value. That action was prompted by a report of an engine compressor core fairing failure during engine ground runs on a BRR Model BR700- 710A1-10 turbofan engine installed on a Gulfstream G-V aircraft. That condition, if not corrected, could result in engine compressor or combustion core fairing detachment and damage to the engine bypass duct, resulting in engine failure and damage to the airplane.

Since the issuance of that AD, the Luftfahrt-Bundesamt (LBA), which is the airworthiness authority for Germany, has notified the FAA that they have determined, based on ongoing investigations and results of successful repetitive inspections, that the inspection interval can be safely increased. They also determined that if an engine core fairing was removed, an initial inspection and follow-on inspection at the current 50 hour TIS interval would be required to insure correct installation, before the 150 hour repetitive time-in-service (TIS) interval is permitted. They also instituted an inspection requirement for loose engine core fairings to verify proper installation and allowed the use of repaired engine core fairings. The LBA issued AD 1998-467/2 following publication of BRR Service Bulletin (SB) No. BR700-72-900062, Revision 3, dated March 24,1999, that increases the repetitive inspection intervals.

This engine model is manufactured in Germany and is type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the LBA has kept the FAA informed of the situation described above. The FAA has examined the findings of the LBA, reviewed all available information, and

[[Page 44667]]

determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would revise AD 98-24-03 to increase the repetitive inspection interval to 150 hours time-in-service (TIS) following a successful initial inspection and one follow-on inspection at the current 50 hours TIS inspection interval. Any engine core fairings or fasteners that have been removed, repaired, or replaced will require an initial inspection before flight and one follow-on inspection at the 50 hours TIS interval before the 150 hour TIS inspection interval is allowed.

There exists no adverse economic impact because this proposed rule only increases the repetitive inspection interval.

The regulations proposed herein would 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 proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this proposed regulation (1) is not a ``significant regulatory action'' under Executive Order 12866; (2) is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting 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.

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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 39-11050 (64 FR 9056, February 24, 1999), and by adding a new airworthiness directive, to read as follows:

   BMW Rolls-Royce GmbH: Docket No. 98-ANE-74-AD. Revises AD 98-24-03, Amendment 39-11050.

   Applicability: BMW Rolls-Royce GmbH (BRR) Model BR700-710A1-10 and BR700-710A2-20 turbofan engines installed on, but not limited to, Gulfstream Aerospace G-V and Bombardier BD-700-1A10 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 (e) 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 engine compressor and combustion core fairing (also referred to as the engine core fairing) detachment which could result in damage to the engine bypass duct, engine failure and damage to the aircraft, accomplish the following:

   (a) Prior to further flight, visually inspect the engine core fairings and fasteners to ensure correct installation and for cracks, loose fairings, or fasteners, and if loose, cracked, damaged, or improperly installed, repair or replace with serviceable parts. Torque all the fasteners to the increased torque value, in accordance with BRR Service Bulletin (SB) BR700-72-900062, Revision 1, dated October 29, 1998, or Revision 2, dated November 3, 1998, or Revision 3, dated March 24, 1999.

   (b) Thereafter, except as provided in paragraphs (c) or (d) of this AD, at intervals not to exceed 50 hours time-in-service (TIS) since last inspection, visually inspect the engine core fairings and fasteners for cracks, loose fairings, or fasteners, and, if loose, cracked, or damaged, repair or replace with serviceable parts. Torque all the fasteners to the increased torque value, in accordance with BRR SB BR700-72-900062, Revision 2, dated November 3, 1998, or Revision 3, dated March 24, 1999.

   (c) Following an initial inspection in accordance with paragraph (a) of this AD, and one follow-on inspection in accordance with paragraph (b), if both inspections found no cracks, damage, loose fairings or fasteners the repetitive inspection interval may be increased to 150 hours TIS since last inspection in accordance with the procedures described in paragraph (b) of this AD.

   (d) Reinspection and retorquing prior to further flight is required in accordance with paragraph (a) of this AD, following any engine core fairing or fastener which has been removed, repaired or replaced. One successful follow-on inspection and retorque in accordance with paragraph (b) of this AD must be accomplished before the repetitive 150 hour TIS inspection interval described in paragraph (c) of this AD is permitted.

   (e) 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, Engine 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, Engine Certification Office.

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

   Issued in Burlington, Massachusetts, on August 11, 1999. David A. Downey, Assistant Manager, Engine and Propeller Directorate, Aircraft Certification Service.

   [FR Doc. 99-21332Filed8-16-99; 8:45 am]

   BILLING CODE 4910-13-U