[Federal Register Volume 66, Number 63 (Monday, April 2, 2001)]
[Rules and Regulations]
[Pages 17506-17508]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-7700]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-15-AD; Amendment 39-12160; AD 2001-06-13]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model DHC-8-100, -200, 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, -200, and -300 series 
airplanes, that requires inspecting the endcaps of the main landing 
gear selector valve for leaks of hydraulic oil and, if leaks are 
detected, replacing the leaking endcaps or the entire selector valve. 
This amendment also requires eventual replacement or rework of certain 
selector valves, which will terminate the repetitive inspections. This 
amendment is prompted by a report of the collapse of the main landing 
gear due to an external leak of hydraulic oil in the landing gear 
selector valve, resulting from a fracture of the endcap. The actions 
specified by this AD are intended to prevent leaks of hydraulic oil 
from the main landing gear selector valve, which could result in the 
collapse of the main landing gear.

DATES: Effective May 7, 2001.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of May 7, 2001.

ADDRESSES: The service information referenced in this AD may be 
obtained from Bombardier, Inc., Bombardier Regional Aircraft Division, 
123 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, 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: James E. Delisio, Aerospace Engineer, 
Airframe and Propulsion Branch, ANE-171, FAA, New York Aircraft 
Certification Office, 10 Fifth Street, Third Floor, Valley Stream, New 
York 11581; telephone (516) 256-7521; 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, -200, and -300 series airplanes was published in the Federal 
Register on September 27, 2000 (65 FR 58011). That action proposed to 
require repetitive inspections of the endcaps of the main landing gear 
selector valve for leaks of hydraulic oil and, if leaks are detected, 
replacing the leaking endcaps or the entire selector valve. That action 
also proposed to require eventual replacement or rework of certain 
selector valves, which terminates the repetitive inspections.

Public Comment

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Request To Specify Terminating Action

    One commenter, an airline operator, points out that replacement of 
the endcap having part number (P/N) 52982 on a main landing gear 
selector valve having P/N 57420-5 is virtually the same action as 
specified in paragraph (c)(2) of the proposed rule. Therefore, the 
commenter requests that the FAA specify that such replacement on a 
selector valve having P/N 57420-5 also constitutes terminating action 
for the repetitive inspections required by paragraph (a) of the 
proposed rule.
    The FAA agrees with the commenter for the reason stated. We have 
revised paragraph (b)(1) of the AD to reflect that change.

Conclusion

    After careful review of the available data, including the comment 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the change described 
previously. The FAA has determined that this change will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

[[Page 17507]]

Cost Impact

    The FAA estimates that 235 airplanes of U.S. registry would be 
affected by this AD, that it will take approximately 9 work hours per 
airplane to accomplish the required inspection and replacement of the 
main landing gear selector valve (if a leak of hydraulic oil is 
detected at the first inspection), and that the average labor rate is 
$60 per work hour. If the operator chooses to replace the endcaps and 
do repetitive inspections prior to replacing the main landing gear 
selector valve, the number of work hours will be greater. Required 
parts will be provided at no charge to operators. Based on these 
figures, the cost impact of the AD on U.S. operators is estimated to be 
$126,900, or $540 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. The cost impact figures discussed 
in AD rulemaking actions represent only the time necessary to perform 
the specific actions actually required by the AD. These figures 
typically do not include incidental costs, such as the time required to 
gain access and close up, planning time, or time necessitated by other 
administrative actions.

Regulatory Impact

    The regulations adopted herein will not have a substantial direct 
effect 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, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    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:

2001-06-13  Bombardier, Inc. (Formerly de Havilland): Amendment 39-
12160. Docket 2000-NM-15-AD.

    Applicability: Model DHC-8-100, -200, and -300 series airplanes, 
serial numbers 003 through 182 inclusive; and 184 through 531 
inclusive; certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
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 (d) 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 the collapse of the main landing gear due to leaks of 
hydraulic oil from the main landing gear selector valve, accomplish 
the following:

Inspection

    (a) Within 100 flight cycles after the effective date of this 
AD, perform a general visual inspection of the endcaps of the main 
landing gear selector valve for the presence of hydraulic oil, in 
accordance with the Accomplishment Instructions of Bombardier Alert 
Service Bulletin A8-32-145, Revision `A', dated December 3, 1999. 
Repeat the inspection thereafter at intervals not to exceed 400 
flight hours until the requirements of paragraph (c) of this AD are 
accomplished.

    Note 2: For the purposes of this AD, a general visual inspection 
is defined as: ``A visual examination of an interior or exterior 
area, installation, or assembly to detect obvious damage, failure, 
or irregularity. This level of inspection is made under normally 
available lighting conditions such as daylight, hangar lighting, 
flashlight, or drop-light, and may require removal or opening of 
access panels or doors. Stands, ladders, or platforms may be 
required to gain proximity to the area being checked.''

Replacement or Modification

    (b) If any hydraulic oil is detected on either endcap during any 
inspection required by paragraph (a) of this AD: Prior to further 
flight, perform the actions specified in either paragraph (b)(1) or 
(b)(2) of this AD.
    (1) Replace the existing aluminum endcaps, part number (P/N) 
34629, with new stainless steel endcaps, P/N 52982, as specified in 
paragraph (b)(1)(i) or (b)(1)(ii) of this AD, as applicable; in 
accordance with the Accomplishment Instructions of Bombardier Alert 
Service Bulletin A8-32-145, Revision `A', dated December 3, 1999.
    (i) For main landing gear selector valves having P/N 57420, P/N 
57420-1, or P/N 57420-3, repeat the inspections required by 
paragraph (a) of this AD at intervals not to exceed 400 flight hours 
until the requirements of paragraph (c) of this AD are met.
    (ii) For main landing gear selector valves having P/N 57420-5, 
replacement of the endcaps having P/N 52982 constitutes compliance 
with the requirements of this AD.
    (2) Replace the main landing gear selector valve with a valve 
having P/N 57420-5A, in accordance with the Accomplishment 
Instructions of Bombardier Alert Service Bulletin A8-32-145, 
Revision `A', dated December 3, 1999. This action terminates the 
inspections required by paragraph (a) of this AD.

    Note 3: Use care when removing the endcaps, so that the internal 
components do not fall on the ground and get damaged.

    (c) Within 12 months after the effective date of this AD: 
Perform the actions specified in either paragraph (c)(1) or (c)(2) 
of this AD as applicable, in accordance with the Accomplishment 
Instructions of Bombardier Alert Service Bulletin A8-32-145, 
Revision `A', dated December 3, 1999. Accomplishment of either 
paragraph (c)(1) or (c)(2) terminates the repetitive inspection 
requirements of this AD.
    (1) If a main landing gear selector valve having P/N 57420, P/N 
57420-1, or P/N 57420-3 is installed, remove it and replace it with 
a valve having P/N 57420-5A.
    (2) If a main landing gear selector valve having P/N 57420-5 is 
installed, remove it and replace it with a valve having P/N 57420-5A 
or modify the valve to the P/N 57420-5A configuration (ModSum 
8Q100802).

Alternative Methods of Compliance

    (d) 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. 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.


[[Page 17508]]


    Note 4: 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

    (e) 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

    (f) The actions shall be done in accordance with Bombardier 
Alert Service Bulletin A8-32-145, Revision `A', dated December 3, 
1999. 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, 123 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, 
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 5: The subject of this AD is addressed in Canadian 
airworthiness directive CF-99-22, dated August 30, 1999.

Effective Date

    (g) This amendment becomes effective on May 7, 2001.

    Issued in Renton, Washington, on March 22, 2001.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-7700 Filed 3-30-01; 8:45 am]
BILLING CODE 4910-13-P