Airworthiness Directives; de Havilland Model DHC-7 Series Airplanes

[Federal Register Volume 61, Number 102 (Friday, May 24, 1996)]
[Rules and Regulations]
[Pages 26088-26090]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-12729]



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[[Page 26089]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-NM-110-AD; Amendment 39-9631; AD 96-11-06]
RIN 2120-AA64


Airworthiness Directives; de Havilland Model DHC-7 Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain de Havilland Model DHC-7 series airplanes, that 
requires modification of the emergency lights circuitry. This amendment 
is prompted by reports of the emergency lights turning on inadvertently 
due to voltage spikes from other equipment; and reports that the 
existing emergency light switch arrangement allows the flight 
compartment and flight attendant's panel switches to override each 
other. The actions specified by this AD are intended to prevent such 
failures of the emergency light systems, which could prevent the use of 
the emergency lights in the event of an emergency.

DATES: Effective June 28, 1996.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of June 28, 1996.

ADDRESSES: The service information referenced in this AD may be 
obtained from Bombardier, Inc., Bombardier Regional Aircraft Division, 
Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. This information 
may be examined at the Federal Aviation Administration (FAA), Transport 
Airplane Directorate, Rules Docket, 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; or at the Office of the Federal Register, 800 North 
Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Wing Chan, 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) 256-7511; fax (516) 568-
2716.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain de Havilland Model DHC-7 
series airplanes was published in the Federal Register on January 9, 
1996 (61 FR 636). That action proposed to require modification of the 
emergency lights circuitry.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Support for the Proposal

    Two commenters support the proposed rule.

Request To Include an Additional Modification Requirement

    One commenter requests that proposed rule be revised to include a 
requirement to install Modification 7/2622. This modification is 
described in de Havilland Service Bulletin 7-33-23 and also affects the 
emergency lighting system. The commenter mentions that this 
modification is mandated by Canadian airworthiness directive CF 95-03. 
The commenter states that, by including a requirement in the proposal 
to install Modification 7/2622, safety would be enhanced and 
unnecessary requests for alternate means of compliance would be 
avoided.
    The FAA does not concur with the commenter's request to revise this 
AD action to require installation of Modification 7/2622. The FAA finds 
that, although the unsafe condition that prompted the Transport Canada 
airworthiness action to mandate that modification concerns the failure 
of the emergency lighting systems, the cause of that failure is 
different from the causes of failure addressed in this AD. 
Additionally, the modification affects some airplanes other than those 
identified in the applicability of this AD.
    However, the FAA is considering separate rulemaking action to 
address the installation of Modification 7/2622 on applicable 
airplanes.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule as proposed.

Cost Impact

    The FAA estimates that 14 airplanes of U.S. registry will be 
affected by this AD, that it will take approximately 8 work hours per 
airplane to accomplish the required actions, and that the average labor 
rate is $60 per work hour. Required parts will be provided at no cost 
to the operators. Based on these figures, the cost impact of the AD on 
U.S. operators is estimated to be $6,720, or $480 per airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the 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 adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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.

[[Page 26090]]

Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

96-11-06  De Havilland, Inc.: Amendment 39-9631. Docket 95-NM-110-
AD.

    Applicability: Model DHC-7 series airplanes, serial numbers 3 
through 27 inclusive, on which de Havilland Modification No. 7/1697 
has not been installed; certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise 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 emergency lighting system due to 
voltage spikes from other equipment or due to inadvertent override 
of the emergency lighting switches, accomplish the following:
    (a) Within 6 months after the effective date of this AD, modify 
the emergency lights circuitry by accomplishing de Havilland 
Modification No. 7/1697 (Emergency Lights- Revised Switching Logic), 
in accordance with the Accomplishment Instructions of de Havilland 
Service Bulletin No. 7-33-7, dated October 17, 1980.
    (b) As of the effective date of this AD, no person shall install 
an emergency light switch, part number MS24659-21A, on any airplane 
subject to 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.
    (e) The modification shall be done in accordance with de 
Havilland Service Bulletin No. 7-33-7, dated October 17, 1980. This 
incorporation by reference was approved by the Director of the 
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 
51. Copies may be obtained from Bombardier, Inc., Bombardier 
Regional Aircraft Division, Garratt Boulevard, Downsview, Ontario 
M3K 1Y5, Canada. Copies may be inspected at the FAA, Transport 
Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or 
at the FAA, New York Aircraft Certification Office, Engine and 
Propeller Directorate, 10 Fifth Street, Third Floor, , Valley 
Stream, New York 11581; or at the Office of the Federal Register, 
800 North Capitol Street, NW., suite 700, Washington, DC.
    (f) This amendment becomes effective on June 28, 1996.

    Issued in Renton, Washington, on May 15, 1996.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-12729 Filed 5-23-96; 8:45 am]
BILLING CODE 4910-13-U

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