Airworthiness Directives; Bombardier Model DHC-8-100 and -300 Series Airplanes

[Federal Register Volume 64, Number 183 (Wednesday, September 22, 1999)]
[Rules and Regulations]
[Pages 51199-51200]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-24148]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-58-AD; Amendment 39-11321; AD 99-19-34]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model DHC-8-100 and -300 
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 Bombardier Model DHC-8-100 and -300 series 
airplanes, that requires modification of certain hydraulic systems that 
provide hydraulic pressure for the control of the rudder and for the 
main landing gear brakes. 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 damage to certain hydraulic system components in the number 
2 engine nacelle, which could result in loss of the number 1 and number 
2 hydraulic systems, and consequent reduced controllability of the 
airplane.

DATES: Effective October 27, 1999.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of October 27, 1999.

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:
Anthony Gallo, 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) 256-7510; 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 Bombardier Model DHC-8-100 
and -300 series airplanes was published in the Federal Register on July 
7, 1999 (64 FR 36624). That action proposed to require modification of 
certain hydraulic systems that provide hydraulic pressure for the 
control of the rudder and for the main landing gear brakes.

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 148 airplanes of U.S. registry will be 
affected by this AD.
    For airplanes identified in Bombardier Service Bulletin S.B. 8-32-
128, Revision `C,' it will take between 15 and 40 works hours per 
airplane to accomplish the required modification, at an average labor 
rate of $60 per work hour. Required parts will be provided by the 
manufacturer at no cost to the operators. Based on these figures, the 
cost impact of the modification required by this AD on U.S. operators 
is estimated to be between $133,200 and $355,200, or between $900 and 
$2,400 per airplane.
    For airplanes identified in Bombardier Service Bulletin S.B. 8-29-
23, it will take approximately 346 work hours per airplane to 
accomplish the required relocation, at an average labor rate of $60 per 
work hour. Required parts will be provided by the manufacturer at no 
cost to the operators. Based on these figures, the cost impact of the 
modification required by this AD on U.S. operators is estimated to be 
$3,072,480, or $20,760 per airplane.
    For airplanes identified in Bombardier Service Bulletin S.B. 8-29-
29, it will take approximately 120 work hours per airplane to 
accomplish the required installation, at an average labor rate of $60 
per work hour. Required parts will be provided by the manufacturer at 
no cost to the operators. Based on these figures, the cost impact of 
the installation required by this AD on U.S. operators is estimated to 
be $1,065,600, or $7,200 per airplane.

[[Page 51200]]

    The cost impact figures discussed above are 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:

99-19-34  Bombardier, Inc. (Formerly de Havilland, Inc.): Amendment 
39-11321. Docket 97-NM-58-AD.

    Applicability: Model DHC-8-100 and -300 series airplanes having 
serial numbers 003 through 405; except those airplanes on which 
Bombardier Modifications 8/1152 and 8/1982 have been installed, and 
on which either Bombardier Modification 8/1983 or 8/2781 has 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 damage to certain hydraulic system components in the 
number 2 engine nacelle, which could result in loss of the number 1 
and number 2 hydraulic systems, and consequent reduced 
controllability of the airplane, accomplish the following:
    (a) Within 18 months after the effective date of this AD, modify 
certain hydraulic systems that provide hydraulic pressure for the 
control of the rudder and for the main landing gear brakes by 
accomplishing the requirements of paragraph (a)(1) or (a)(2), as 
applicable, in accordance with Bombardier Service Bulletin S.B. 8-
32-128, Revision `C,' dated March 27, 1998.
    (1) For all airplanes on which Bombardier Modification 8/1152 
has been installed: Accomplish Part A of the Accomplishment 
Instructions of the service bulletin.
    (2) For all airplanes on which Bombardier Modification 8/1152 
has not been installed: Accomplish Part B of the Accomplishment 
Instructions of the service bulletin.
    (b) Within 18 months after the effective date of this AD, 
accomplish the actions specific in either paragraph (b)(1) or (b)(2) 
of this AD.
    (1) Relocate the number 2 standby power unit (SPU) of the number 
2 hydraulic system in accordance with Bombardier Service Bulletin 
S.B. 8-29-23, dated December 6, 1996; or
    (2) Install a hydraulic rudder isolation system in the number 1 
and number 2 hydraulic systems in accordance with Bombardier Service 
Bulletin S.B. 8-29-29, dated February 27, 1998.
    (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.

Incorporation by Reference

    (e) The actions shall be done in accordance with Bombardier 
Service Bulletin S.B. 8-32-128, Revision `C,' dated March 27, 1998; 
Bombardier Service Bulletin S.B. 8-29-23, dated December 6, 1996; or 
Bombardier Service Bulletin S.B. 8-29-29, dated February 27, 1998; 
as applicable. 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 directives CF-96-25R1, dated January 16, 1997, and CF-
96-25R2, dated September 10, 1998.

    (f) This amendment becomes effective on October 27, 1999.

    Issued in Renton, Washington, on September 10, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-24148 Filed 9-21-99; 8:45 am]
BILLING CODE 4910-13-P

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