[Federal Register Volume 61, Number 99 (Tuesday, May 21, 1996)]
[Proposed Rules]
[Pages 25417-25418]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-12602]



 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
 
 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
 ========================================================================
 

  Federal Register / Vol. 61, No. 99 / Tuesday, May 21, 1996 / Proposed 
Rules  

[[Page 25417]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-NM-264-AD]
RIN 2120-AA64


Airworthiness Directives; de Havilland Model DHC-7 Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain de Havilland Model DHC-7 
series airplanes. This proposal would require repetitive non-
destructive inspections to detect disbonding of fuselage skin panels, 
and repair, if necessary. This proposal is prompted by a report of 
disbonding on fuselage skin panels, which was attributed to a 
manufacturing process error. The actions specified by the proposed AD 
are intended to prevent disbonding of the skin panels of the fuselage, 
which could result in degradation of the structural capability of the 
airplane fuselage.

DATES: Comments must be received by July 1, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-264-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, Canada M3K 1Y5. This information 
may be examined at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Sol Maroof, Aerospace Engineer, 
Airframe and Propulsion Branch, ANE-171, FAA, New York Aircraft 
Certification Office, Engine and Propeller Directorate, 10 Fifth 
Street, Third Floor, Valley Stream, New York 11581; telephone (516) 
256-7522; 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 filed in 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 95-NM-264-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-103, Attention: Rules 
Docket No. 95-NM-264-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    Transport Canada Aviation, which is the airworthiness authority for 
Canada, recently notified the FAA that an unsafe condition may exist on 
certain de Havilland Model DHC-7 series airplanes. Transport Canada 
Aviation advises that it has received a report indicating that, during 
a routine inspection, disbonding was discovered on a fuselage skin 
panel. Investigation revealed that the apparent cause of the disbonding 
was due to the initial material preparation process that was used on 
the fuselage skin panels during manufacture. Such disbonding, if not 
corrected, could result in degradation of the structural capability of 
the airplane fuselage.

Explanation of Relevant Service Information

    Bombardier has issued Service Bulletin S.B. 7-51-1, Revision `A', 
dated March 31, 1995, which describes procedures for conducting 
repetitive non-destructive inspections of de Havilland Model DHC-7 
series airplanes to detect disbonding of the fuselage skin panels. 
Transport Canada Aviation classified this service bulletin as mandatory 
and issued Canadian airworthiness directive CF-94-15 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, Transport Canada Aviation has kept 
the FAA informed of the situation described above. The FAA has examined 
the findings of Transport Canada Aviation, 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 the Requirements of the Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design, the 
proposed AD would require repetitive non-destructive inspections to 
detect disbonding of the fuselage skin panels. These inspections would 
be required to be accomplished in accordance with the service bulletin 
described previously.

[[Page 25418]]

    If any disbonding is detected on any fuselage skin panel, its 
repair would be required to be accomplished in accordance with a method 
approved by the FAA.

Cost Impact

    The FAA estimates that 50 de Havilland Model DHC-7 series airplanes 
of U.S. registry would be affected by this proposed AD, that it would 
take approximately 18 work hours per airplane to accomplish the 
proposed inspections, 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 $54,000, or $1,080 per airplane, per 
inspection cycle.
    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:

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:

De Havilland, Inc: Docket 95-NM-264-AD.

    Applicability: Model DHC-7 series airplanes, serial numbers 003 
through 113 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 (b) 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 disbonding of the skin panels of the fuselage, which 
could result in degradation of the structural capability of the 
airplane fuselage, accomplish the following:
    (a) Within 6 months after the effective date of this AD, perform 
a non-destructive inspection to detect disbonding of the fuselage 
skin panels, in accordance with the Accomplishment Instructions of 
Bombardier Service Bulletin S.B. 7-51-1, Revision 'A', dated March 
31, 1995.
    (1) If no disbonding is detected, repeat the inspection 
thereafter at intervals not to exceed 3 years.
    (2) If any disbonding is detected, prior to further flight, 
repair it in accordance with a method approved by the Manager, New 
York Aircraft Certification Office (ACO), FAA, Engine and Propeller 
Directorate.
    (b) 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 ACO. 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.

    (c) 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.

    Issued in Renton, Washington, on May 14, 1996.
S. R. Miller,
Acting Manager,Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-12602 Filed 5-20-96; 8:45 am]
BILLING CODE 4910-13-P