Airworthiness directives: Bombardier,

[Federal Register: October 2, 1998 (Volume 63, Number 191)]

[Proposed Rules]

[Page 52994-52996]

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

[DOCID:fr02oc98-25]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-237-AD]

RIN 2120-AA64

Airworthiness Directives; Bombardier Model DHC-7 and DHC-8 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

SUMMARY: This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Bombardier Model DHC-7 and DHC-8 series airplanes. This proposal would require a one-time visual inspection to determine the serial number of the brake shuttle valves of the main landing gear (MLG); and replacement of the filter fittings with new filter fittings, if necessary. This proposal is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by the proposed AD are intended to ensure that proper filter fittings are installed. Installation of improper filter fittings could result in failure of the brake shuttle valves, and consequent loss of brake effectiveness, which could reduce controllability of the airplane during taxi, takeoff, and landing roll.

DATES: Comments must be received by November 2, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-237-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays.

The service information referenced in the proposed rule may be obtained from Bombardier, Inc., Bombardier Regional Aircraft Division, Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Engine and Propeller Directorate, New York Aircraft Certification Office, 10 Fifth Street, Third Floor, Valley Stream, New York.

[[Page 52995]]

FOR FURTHER INFORMATION CONTACT: Anthony E. Gallo, Aerospace Engineer, Systems and Flight Test Branch, ANE-172, FAA, Engine and Propeller Directorate, New York Aircraft Certification Office, 10 Fifth Street, Third Floor, Valley Stream, New York 11581; telephone (516) 256-7510; fax (516) 568-2716.

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 shall 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-NM-237-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, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-237-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

Transport Canada Aviation (TCA), which is the airworthiness authority for Canada, notified the FAA that an unsafe condition may exist on certain Bombardier Model DHC-7 and DHC-8 series airplanes. TCA advises that an operator reported an incident wherein the hydraulic pressure for the main landing gear (MLG) remained applied on one wheel brake after the wheel brake was released. Investigation revealed that a defective filter fitting inside the brake shuttle valve had failed, which blocked the valve port and prevented the flow of hydraulic fluid from the brakes. The defective filter fittings were fitted into a specific batch of brake shuttle valves. Installation of improper filter fittings, if not corrected, could result in failure of the brake shuttle valves, and consequent loss of brake effectiveness, which could reduce controllability of the airplane during taxi, takeoff, and landing roll.

Explanation of Relevant Service Information

The manufacturer has issued Bombardier Alert Service Bulletins S.B. A7-32-102, Revision `A,' dated November 26, 1997 (for Model DHC-7 series airplanes), and S.B. A8-32-139, Revision `A,' dated December 19, 1997 (for Model DHC-8 series airplanes). These alert service bulletins describe procedures for a one-time visual inspection to determine the serial numbers of the brake shuttle valves of the MLG; and replacement of the filter fittings inside the brake shuttle valve with new filter fittings, if necessary. Accomplishment of the actions specified in the alert service bulletins is intended to adequately address the identified unsafe condition. Transport Canada Aviation classified these alert service bulletins as mandatory and issued Canadian airworthiness directive CF-98-05, dated March 2, 1998, in order to assure the continued airworthiness of these airplanes in Canada.

FAA's Conclusions

These airplane models are manufactured in Canada and are 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, TCA has kept the FAA informed of the situation described above. The FAA has examined the findings of TCA, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, the proposed AD would require accomplishment of the actions specified in the alert service bulletins described previously.

Cost Impact

The FAA estimates that 260 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 1 work hour per airplane to accomplish the proposed inspection, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $15,600, or $60 per airplane.

The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted.

Regulatory Impact

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:

[[Page 52996]]

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:

    Bombardier, Inc. (Formerly de Havilland, Inc.): Docket 98-NM-237-AD.

    Applicability: Model DHC-7-1, -100, -101, -102, and -103 series airplanes, having serial numbers (S/N) 003 through 113 inclusive; and Model DHC-8-100, -200, and -300 series airplanes, having S/N's 003 through 498 inclusive; certificated in any category.

    Note 1: This AD applies to each airplane 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 airplanes 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.

    Compliance: Required as indicated, unless accomplished previously.

    To prevent failure of the brake shuttle valves, and consequent loss of the brake effectiveness, due to installation of improper filter fittings, which could reduce controllability of the airplane during taxi, takeoff, and landing roll, accomplish the following:

    (a) Within 3 months after the effective date of this AD, perform a one-time visual inspection to determine the serial numbers of the brake shuttle valves of the main landing gear (MLG), in accordance with Bombardier Alert Service Bulletin S.B. A7-32-102, Revision `A,' dated November 26, 1997 (for Model DHC-7 series airplanes), or S.B. A8-32-139, Revision A,' dated December 19, 1997 (for Model DHC-8 series airplanes), as applicable. If any brake shuttle valve having S/N 2162A through 2244A inclusive is installed, prior to further flight, replace the filter fittings with new filter fittings, in accordance with the applicable alert service bulletin.

    (b) As of the effective date of this AD, no person shall install a brake shuttle valve having part number 5084-1 on any airplane, unless it has been inspected and any defective filter fitting replaced, in accordance with the requirements of this AD.

    (c) 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, New York Aircraft Certification Office (ACO), FAA, Engine and Propeller Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, New York ACO.

    Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the New York ACO.

    (d) 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 airplane to a location where the requirements of this AD can be accomplished.

    Note 3: The subject of this AD is addressed in Canadian airworthiness directive CF-98-05, dated March 2, 1998.

    Issued in Renton, Washington, on September 25, 1998. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

    [FR Doc. 98-26353Filed10-1-98; 8:45 am]

    BILLING CODE 4910-13-U

VLEX uses login cookies to provide you with a better browsing experience. If you click on 'Accept' or continue browsing this site we consider that you accept our cookie policy. ACCEPT