[Federal Register Volume 64, Number 200 (Monday, October 18, 1999)]
[Rules and Regulations]
[Pages 56161-56163]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-26866]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-324-AD; Amendment 39-11373; AD 99-21-27]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model DHC-8-311 and -315 
Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to certain Bombardier Model DHC-8-311 and -315 series 
airplanes, that currently requires replacement of the nitrogen cylinder 
assemblies that inflate the airplane's ditching dams with improved 
nitrogen cylinder assemblies. This amendment expands the applicability 
of the existing AD. 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 November 22, 1999.
    The incorporation by reference of Bombardier Service Bulletin S.B. 
8-25-122, dated October 10, 1997, listed in the regulations, was 
approved previously by the Director of the Federal Register as of July 
8, 1998 (63 FR 30121, June 3, 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) by superseding AD 98-11-25, 
amendment 39-10550 (63 FR 30121, June 3, 1998), which is applicable to 
certain Bombardier Model DHC-8-311 and -315 series airplanes, was 
published in the Federal Register on August 12, 1999 (64 FR 43959). The 
action proposed to supersede AD 98-11-25 to continue to require 
replacement of the nitrogen cylinder assemblies that inflate the 
airplane's ditching dams with improved nitrogen cylinder assemblies. 
That action also proposed to expand the applicability of the existing 
AD.

[[Page 56162]]

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

    There are approximately 2 airplanes of U.S. registry that will be 
affected by this AD.
    The replacement that is currently required by AD 98-11-25, and 
retained in this AD, will take approximately 4 work hours per airplane 
to accomplish, at an average labor rate of $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 replacement currently required 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 removing amendment 39-10550 (63 FR 
30121, June 3, 1998), and by adding a new airworthiness directive (AD), 
amendment 39-11373, to read as follows:
99-21-27  Bombardier, Inc. (Formerly de Havilland, Inc.): Amendment 
39-11373. Docket 98-NM-324-AD. Supersedes AD 98-11-25, Amendment 39-
10550.

    Applicability: Model DHC-8-311 and -315 series airplanes in the 
medium and high gross weight configuration, on which Bombardier 
Change Request CR803SO00001, CR803SO00001-1, CR803SO00002, 
CR803SO00002-1, 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 (e) 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:

Restatement of the Requirements of AD 98-11-25, Amendment 39-10550

    (a) For 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: Within 6 months 
after July 8, 1998 (the effective date of AD 98-11-25), 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 de Havilland Service Bulletin S.B. 8-25-122, dated October 10, 
1997.
    (b) For 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: As of July 8, 
1998, no person shall install on any airplane any nitrogen cylinder 
assembly having part number (P/N) 410870(BSC) or 410870-1.

New Requirements of This AD

Replacement

    (c) For airplanes other than those identified in paragraph (a) 
of this AD: 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 having P/N 410870-3 or -5, 
that incorporates an improved valve assembly (reference de Havilland 
Modification 8/3154), in accordance with de Havilland Service 
Bulletin S.B. 8-25-122, dated October 10, 1997.

Spares

    (d) For airplanes other than those identified in paragraph (a) 
of this AD: As of the effective date of this AD, no person shall 
install on any airplane any nitrogen cylinder assembly having P/N 
410870(BSC) or 410870-1.

Alternative Methods of Compliance

    (e) 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.

Special Flight Permits

    (f) 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.

Incorporation by Reference

    (g) The replacement shall be done in accordance with de 
Havilland Service Bulletin S.B. 8-25-122, dated October 10, 1997. 
This incorporation by reference was approved previously by the 
Director of the Federal Register as of July 8, 1998 (63 FR 30121, 
June 3, 1998). Copies may be obtained from Bombardier, Inc., 
Bombardier Regional Aircraft Division, Garratt Boulevard,

[[Page 56163]]

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-97-21R1, dated July 22, 1998.

    (h) This amendment becomes effective on November 22, 1999.

    Issued in Renton, Washington, on October 7, 1999.
D. L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-26866 Filed 10-15-99; 8:45 am]
BILLING CODE 4910-13-U