[Federal Register Volume 63, Number 106 (Wednesday, June 3, 1998)]
[Rules and Regulations]
[Pages 30121-30122]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-14222]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-60-AD; Amendment 39-10550; AD 98-11-25]
RIN 2120-AA64


Airworthiness Directives; de Havilland Model DHC-8-311 and -315 
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-8-311 and -315 series 
airplanes, that requires replacement of the nitrogen cylinder 
assemblies that inflate the airplane's ditching dams with improved 
nitrogen cylinder assemblies. This amendment is prompted by issuance of 
mandatory continuing airworthiness information by a foreign civil 
airworthiness authority. The actions specified by this AD are intended 
to prevent failure of the ditching dams to inflate fully during an 
emergency water landing, which could result in water entering the 
airplane.

DATES: Effective July 8, 1998.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of July 8, 1998.

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: Ezra Sasson, 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) 256-7520; 
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-8-
311 and -315 series airplanes was published in the Federal Register on 
April 2, 1998 (63 FR 16169). That action proposed to require 
replacement of the nitrogen cylinder assemblies that inflate the 
airplane's ditching dams with improved nitrogen cylinder assemblies.

Comments

    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.

Conclusion

    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 2 airplanes of U.S. registry will be 
affected by this AD, that it will take approximately 4 work hours per 
airplane to accomplish the required modification, and that the average 
labor rate is $60 per work hour. Required parts will be provided by the 
manufacturer of the nitrogen cylinder assembly at no cost to the 
operator. Based on these figures, the cost impact of the AD on U.S. 
operators is estimated to be $480, or $240 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.


Sec. 39.13  [Amended]

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

98-11-25 De Havilland Inc.: Amendment 39-10550. Docket 98-NM-60-AD.

    Applicability: Model DHC-8-311 and -315 series airplanes in the 
medium and high gross weight configuration, on which Bombardier 
Change Request CR803SO00001, CR803SO00002, CR803CH00046, 
CR803CH00079, CR803CH00105, CR825CH00847, or CR803CH00051 has been 
incorporated; 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 ditching dams to inflate fully during 
an emergency water landing, which could result in water entering the 
airplane, accomplish the following:

[[Page 30122]]

    (a) Within 6 months after the effective date of this AD, replace 
the existing nitrogen cylinder assembly on the ditching dams with a 
new nitrogen cylinder assembly that incorporates an improved valve 
assembly (reference de Havilland Modification 8/3154), in accordance 
with Bombardier Service Bulletin S.B. 8-25-122, dated October 10, 
1997.
    (b) As of the effective date of this AD, no person shall install 
on any airplane any nitrogen cylinder assembly having part number 
410870(BSC) or 410870-1.
    (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 replacement shall be done in accordance with Bombardier 
Service Bulletin S.B. 8-25-122, dated October 10, 1997. 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, 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.

    Note 3: The subject of this AD is addressed in Canadian 
airworthiness directive CF-97-21, dated November 13, 1997.

    (f) This amendment becomes effective on July 8, 1998.

    Issued in Renton, Washington, on May 22, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-14222 Filed 6-2-98; 8:45 am]
BILLING CODE 4910-13-U