[Federal Register Volume 61, Number 100 (Wednesday, May 22, 1996)]
[Proposed Rules]
[Pages 25598-25600]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-12728]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-NM-158-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 all de Havilland Model DHC-7 
series airplanes. This proposal would require certain structural 
inspections, and repair, if necessary. This proposal is 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 
actions specified by the proposed 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.

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-158-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 de Havilland, Inc., Garratt Boulevard, Downsview, Ontario 
M3K 1Y5, Canada. 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,

[[Page 25599]]

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-158-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-158-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 
all de Havilland Model DHC-7 series airplanes. Service experience shows 
that transport category aircraft of this type require certain 
supplemental structural inspections and maintenance to compensate for 
the effects of prolonged time-in-service. As a result, the manufacturer 
has conducted a structural reassessment of these airplanes and has 
identified additional significant structural items where fatigue damage 
is likely to occur. The criteria for this reassessment are contained in 
FAA Advisory Circular (AC) 91-60, ``Continued Airworthiness of Older 
Airplanes.''

Explanation of Relevant Service Information

    De Havilland has issued Temporary Revision (TR 5-84), dated June 
15, 1994, of the DHC-7 Maintenance Manual (PSM 1-7-2), Chapter 5-60-00. 
TR 5-84 was developed based on service experience with the purpose of 
extending the Model DHC-7 series airplanes' life beyond 40,000 total 
flights cycles. It describes procedures for repetitive detailed visual 
inspections to detect cracks, loose or broken fasteners, and 
deformations of the vertical stabilizer, horizontal stabilizer, and 
lower skin panels of the wing. That document also indicates that 
operators should submit the results of these inspections to the 
manufacturer. Transport Canada Aviation classified this document as 
mandatory and issued Canadian airworthiness directive CF-94-19, dated 
October 6, 1994, 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 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, the 
proposed AD would require that operators incorporate, into their FAA-
approved maintenance inspection program, the inspections specified in 
DHC-7 Maintenance Manual (PSM 1-7-2), Chapter 5-60-00, Temporary 
Revision (TR 5-84), dated June 15, 1994. The actions would be required 
to be accomplished in accordance with the document described 
previously.
    Additionally, the proposed AD would require the repair of any 
findings of cracks, loose or broken fasteners, or deformations in 
accordance with either:
    1. The DHC-7 Maintenance Manual; or
    2. The DHC-7 Structural Repair Manual;
    3. Other data meeting the certification basis of the airplane which 
is approved by the Manager, New York Aircraft Certification Office, 
FAA, Engine and Propeller Directorate; or
    -4. Data meeting the certification basis of the airplane which is 
approved by Transport Canada Aviation.

Cost Impact

    The FAA estimates that 50 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 15 work 
hours per airplane to accomplish the proposed actions, 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 
$45,000, or $900 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.

[[Page 25600]]

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 USC 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-158-AD.

    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 
other 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 (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 ensure the continuing structural integrity of these 
airplanes, accomplish the following:
    (a) Within 6 months after the effective date of this AD, 
incorporate into the FAA-approved maintenance inspection program the 
inspections and inspection intervals defined in DHC-7 Maintenance 
Manual (PSM 1-7-2), Chapter 5-60-00, 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.
    (c) 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 5-60-
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.
    (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, 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 Manager, New York ACO.

    (e) Special flight permits may be issued in accordance with 
Secs. 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 15, 1996.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-12728 Filed 5-21-96; 8:45 am]
BILLING CODE 4910-13-U