Airworthiness directives: de Havilland,

[Federal Register: September 3, 1998 (Volume 63, Number 171)]

[Proposed Rules]

[Page 46925-46927]

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

[DOCID:fr03se98-28]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-143-AD]

RIN 2120-AA64

Airworthiness Directives; de Havilland Model DHC-7 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

SUMMARY: This document proposes the supersedure of an existing airworthiness directive (AD), applicable to all de Havilland Model DHC- 7 series airplanes, that currently requires certain structural inspections, and repair, if necessary. This action would require certain structural inspection. 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 detect and correct fatigue cracking in certain significant structural areas, which could reduce the structural integrity of these airplanes.

DATES: Comments must be received by October 5, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-143-AD, 1061 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.

FOR FURTHER INFORMATION CONTACT: Serge Napoleon, Aerospace Engineer, Airframe and Propulsion Branch, ANE-171, FAA, Engine and Propeller Directorate, New York Aircraft Certification Office, 10 Fifth Street, Third Floor, Valley Stream, New York 11581; telephone (516) 256-7512; fax (516) 568-2716.

[[Page 46926]]

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-143-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-143-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

On March 6, 1997, the FAA issued AD 97-06-08, amendment 39-9965 (62 FR 12531, March 17, 1997), applicable to all de Havilland Model DHC-7 series airplanes, to require certain structural inspections, and repair, if necessary. That action was prompted by a structural re- evaluation, which identified certain significant structural items to inspect for fatigue cracking as these airplanes approach and exceed the manufacturer's original design life. The requirements of that AD are intended to prevent fatigue cracking in these areas which, if not detected and corrected in a timely manner, could reduce the structural integrity of these airplanes.

Actions Since Issuance of Previous Rule

Since the issuance of AD 97-06-08, which identified six significant structural areas for repetitive structural inspections to detect fatigue cracking, Transport Canada Aviation (TCA), which is the airworthiness authority for the Canada, identified a seventh area that also requires repetitive structural inspections to detect fatigue cracking. Such cracking, if not detected and corrected in a timely manner, could reduce the structural integrity of these airplanes.

Explanation of Relevant Service Information

The manufacturer has issued de Havilland Dash 7 Maintenance Manual, Product Support Manual (PSM) 1-7-2, Chapter 5, Section 5-60-00, Temporary Revisions (TR) 5-99 and 5-97, both dated December 22, 1997, which describe procedures for Supplementary Inspection Program (SIP) tasks for the additional inspection to detect cracks in the fastener holes located on the left and right wing at stringers 6 and 8. Accomplishment of this inspection will ensure the continued structural airworthiness of Model DHC-7 series airplanes. TCA classified these TR's as mandatory and issued Canadian airworthiness directive CF-94- 19R1, dated January 26, 1998, in order to assure the continued airworthiness of these airplanes in Canada.

FAA's Conclusions

This airplane model is manufactured in Canada 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, 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 State, the proposed AD would supersede AD 97-06-08 to continue to require certain structural inspections, and repair, if necessary. This proposed action also would require an additional structural inspection to detect cracks in the fastener holes located on the left and right wing at stringers 6 and 8. The actions would be required to be accomplished in accordance with the service information described previously.

Cost Impact

There are approximately 50 airplanes of U.S. registry that would be affected by this proposed AD.

The inspections that are currently required by AD 97-06-08, and retained in this AD, take approximately 15 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the currently required actions on U.S. operators is estimated to be $45,000, or $900 per airplane, per inspection cycle.

The new inspection that is proposed in this AD action would take approximately 3 work hours per airplane to accomplish, at an average labor rate $60 per work hour. Based on these figures, the cost impact of the proposed requirements of this AD on U.S. operators is estimated to be $9,000, or $180 per airplane, per inspection cycle.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the current or 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.

[[Page 46927]]

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 39-9965 (62 FR 12531, March 17, 1997), and by adding a new airworthiness directive (AD), to read as follows:

    De Havilland Inc.: Docket 98-NM-143-AD. Supersedes AD 97-06-08, Amendment 39-9965.

    Applicability: All Model DHC-7 series airplanes, 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 (f) 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 ensure the continued structural integrity of these airplanes, accomplish the following:

    Restatement of Requirements of AD 97-06-08, Amendment 39-9965

    (a) Within 6 months after April 21, 1997 (the effective date of AD 97-06-08, amendment 39-9965), incorporate into the FAA-approved maintenance inspection program the inspections and inspection intervals defined in DHC-7 Maintenance Manual (PSM 1-7-2), Chapter 5, Section 5-06-00, Temporary Revision (TR 5-84), dated June 15, 1994; and inspect the significant structural items prior to the thresholds specified in TR 5-84 of PSM 1-7-2. Repeat the inspections thereafter at the intervals specified in TR 5-84 of PSM 1-7-2.

    (b) Prior to further flight, repair any discrepancies detected during any inspection required by paragraph (a) of this AD in accordance with one of the following:

    (1) The DHC-7 Maintenance Manual; or

    (2) The DHC-7 Structural Repair Manual; or

    (3) Other data meeting the certification basis of the airplane which is approved by the Manager, New York Aircraft Certification Office (ACO), FAA, Engine and Propeller Directorate; or

    (4) Data meeting the certification basis of the airplane which is approved by Transport Canada Aviation.

    New Requirements of This AD

    (c) Incorporate into the FAA-approved maintenance inspection program the inspections and inspection intervals defined in the DHC- 7 Maintenance Manual PSM 1-7-2, Supplementary Inspection Program (SIP), Chapter 5, Section 5-60-00, Temporary Revision (TR 5-99), dated December 22, 1997, at the applicable time specified in paragraph (c)(1) or (c)(2) of this AD; and inspect the significant structural items prior to the thresholds specified in TR 5-99 of PSM 1-7-2. Thereafter, repeat the inspection at the intervals specified in TR 5-99 of PSM 1-7-2.

    (1) For airplanes that have accumulated 38,000 or more total flight cycles as of the effective date of this AD: Incorporate within 2,000 flight cycles after the effective date of this AD.

    (2) For airplanes that have accumulated less than 38,000 total flight cycles as of the effective date of this AD: Incorporate prior to the accumulation of 40,000 total flight cycles.

    (d) Incorporate into the FAA-approved maintenance inspection program the inspections and inspection intervals as defined in the DHC-7 Maintenance Manual, Chapter 5, Section 5-60-00, (PSM 1-7-2), Supplementary Inspection Program (SIP), Temporary Revision TR 5-97, dated December 22, 1997, at the applicable time specified in paragraph (d)(1) or (d)(2) of this AD; and inspect the significant structural items prior to the thresholds specified in TR 5-97 of PSM 1-7-2. Thereafter, repeat the inspection at the intervals specified in TR 5-99 of PSM 1-7-2.

    (1) For airplanes that have accumulated 19,000 or more total flight cycles as of the effective date of this AD: Incorporate within 1,000 flight cycles after the effective date of this AD.

    (2) For airplanes that have accumulated less than 19,000 total flight cycles as of the effective date of this AD: Incorporate prior to the accumulation of 20,000 total flight cycles.

    (e) All inspection results, positive or negative, must be reported to de Havilland in accordance with ``Introduction,'' paragraph 5, of DHC-7 Maintenance Manual (PSM 1-7-2), Chapter 5, Section 5-60-00, Temporary Revision (TR 5-84), dated June 15, 1994. Information collection requirements contained in this regulation have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120- 0056.

    (f) 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.

    (g) 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-94-19R1, dated January 26, 1998.

    Issued in Renton, Washington, on August 28, 1998. Vi L. Lipski, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

    [FR Doc. 98-23743Filed9-2-98; 8:45 am]

    BILLING CODE 4910-13-M

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