[Federal Register Volume 59, Number 161 (Monday, August 22, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-20156]


[[Page Unknown]]

[Federal Register: August 22, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-NM-19-AD; Amendment 39-9003; AD 94-17-08]

 

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 all de Havilland Model DHC-7 series airplanes, that 
requires removal of the aluminum or brass hardware in the firewall 
terminal block assembly and replacement with steel hardware. This 
amendment is prompted by the results of an investigation, which 
revealed that corroded aluminum washers in the DC firewall terminal 
block assembly may loosen the electrical connections. The actions 
specified by this AD are intended to prevent interruption of DC 
electrical power due to connections that may have loosened from 
corrosion.

DATES: Effective on September 21, 1994. -
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of September 21, 1994.

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, 181 South Franklin Avenue, Room 202, 
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: Peter Cuneo, Electrical Engineer, 
Systems and Equipment Branch, ANE-173, FAA, Engine and Propeller 
Directorate, New York Aircraft Certification Office, 181 South Franklin 
Avenue, Room 202, Valley Stream, New York 11581; telephone (516) 791-
6427; fax (516) 791-9024.

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 all de Havilland Model DHC-7 
series airplanes was published in the Federal Register on April 22, 
1994 (59 FR 19154). That action proposed to require removal of the 
aluminum or brass hardware in the firewall terminal block assembly and 
replacement with steel hardware (Modification 7/2617). -
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were submitted in response 
to the proposal or the FAA's determination of the cost to the public. 
The FAA has determined that air safety and the public interest require 
the adoption of the rule as proposed. -
    The FAA estimates that 55 airplanes of U.S. registry will be 
affected by this AD, that it will take approximately 3 work hours per 
airplane to accomplish the required actions, and that the average labor 
rate is $55 per work hour. Required parts will be nominal in cost. 
Based on these figures, the total cost impact of the AD on U.S. 
operators is estimated to be $9,075, or $165 per airplane. -
    The total 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. -
    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. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended] -

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

94-17-08 De Havilland, Inc.: Amendment 39-9003. Docket 94-NM-19-AD.

    -Applicability: All Model DHC-7 series airplanes, certificated 
in any category. -
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent interruption of DC electrical power due to 
connections that may have loosened from corrosion, accomplish the 
following: -
    (a) Within 60 days after the effective date of this AD, remove 
the aluminum or brass hardware in the firewall terminal block 
assembly and replace with steel hardware (Modification 7/2617), in 
accordance with de Havilland Service Bulletin S.B. 7-24-69, dated 
October 8, 1993. -
    (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 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: 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. -
    (d) The removal and replacement shall be done in accordance with 
de Havilland Service Bulletin S.B. 7-24-69, dated October 8, 1993. 
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 Engine and Propeller Directorate, New York Aircraft 
Certification Office, 181 South Franklin Avenue, Room 202, Valley 
Stream, New York; or at the Office of the Federal Register, 800 
North Capitol Street, NW., suite 700, Washington, DC. -
    (e) This amendment becomes effective on September 21, 1994.

    Issued in Renton, Washington, on August 11, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-20156 Filed 8-19-94; 8:45 am]
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