AD 2003-25-05

[Federal Register Volume 68, Number 243 (Thursday, December 18, 2003)]
[Rules and Regulations]
[Pages 70428-70429]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-31058]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-266-AD; Amendment 39-13388; AD 2003-25-05]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model DHC-8-102, -103, -106, 
-201, -202, -301, -311, and -315 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 DHC-8-102, -103, -106, -201, -
202, -301, -311, and -315 airplanes, that currently requires 
inspections to detect breakage in the struts of the rear mount strut 
assemblies on the left and right engine nacelles, and replacement of 
any broken struts. The existing AD also requires eventual replacement 
of all currently installed struts with new and/or reworked struts, as 
terminating action for the inspections. The amendment requires new 
repetitive inspections of the strut assemblies for cracking of struts 
replaced per the existing AD, and replacement of any cracked strut with 
a new, machined strut. The amendment also changes the applicability of 
the existing AD by adding certain airplanes and removing certain other 
airplanes, and includes an optional terminating action for the 
repetitive inspections. The actions specified by this AD are intended 
to prevent failure of the engine rear mount struts, which could result 
in reduced structural integrity of the nacelle and engine support 
structure. This action is intended to address the identified unsafe 
conditions.

DATES: Effective January 22, 2004.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of January 22, 2004.

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: Jon Hjelm, Aerospace Engineer, 
Airframe Branch, ANE-171, FAA, New York Aircraft Certification Office, 
10 Fifth Street, Third Floor, Valley Stream, New York 11581; telephone 
(516) 256-7523; fax (516) 568-2716.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 94-04-09, 
amendment 39-8829 (59 FR 8393, February 22, 1994), which is applicable 
to certain Bombardier Model DHC-8-100 and DHC-8-300 airplanes, was 
published in the Federal Register on October 9, 2003 (68 FR 58283). The 
action proposed to require new repetitive inspections of the strut 
assemblies for cracking of struts replaced per the existing AD, and 
replacement of any cracked strut with a new, machined strut. The action 
also proposed to change the applicability of the existing AD by adding 
certain airplanes and removing certain other airplanes, and proposed to 
include an optional terminating action for the repetitive inspections.

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 192 airplanes of U.S. registry that will be 
affected by this AD.
    The actions that are currently required by AD 94-04-09 take 
approximately 16 work hours per airplane to accomplish, at an average 
labor rate of $65 per work hour. Required parts are provided by the 
manufacturer at no cost to the operators. Based on these figures, the 
cost impact of the currently required actions is estimated to be $1,040 
per airplane.
    The new detailed inspection that is required in this AD action 
takes approximately 1 work hour per airplane to accomplish, at an 
average labor rate of $65 per work hour. Based on these figures, the 
cost impact of the required inspection on U.S. operators is estimated 
to be $12,480, or $65 per airplane, per inspection cycle.
    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. 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.
    The optional terminating action, if done, will take approximately 
16 work hours per strut to accomplish, at an average labor rate of $65 
per work hour. Required parts will cost aproxiamately $800 per strut. 
Based on these figures, the cost impact of the optional terminating 
action is estimated to be $1,840 per strut, per airplane.

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

[[Page 70429]]

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 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
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

0
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]

0
2. Section 39.13 is amended by removing amendment 39-8829 (59 FR 8393, 
February 22, 1994), and by adding a new airworthiness directive (AD), 
amendment 39-13388, to read as follows:

2003-25-05 Bombardier, Inc. (Formerly de Havilland, Inc.): Amendment 
39-13388. Docket 2001-NM-266-AD. Supersedes AD 94-04-09, Amendment 
39-8829.

    Applicability: Model DHC-8-102, -103, -106, -201, -202, -301, -
311, and -315 airplanes; serial numbers 003 through 509 inclusive; 
certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent failure of the engine rear mount struts on the left 
and right engine nacelles, which could result in reduced structural 
integrity of the nacelle and engine support structure, accomplish 
the following:

Repetitive Inspections

    (a) Within 1,000 flight hours since installation of any new or 
reworked rear mount strut per the replacement required by paragraph 
(b) of AD 94-04-09, amendment 39-8829, or within 250 flight hours 
after the effective date of this AD, whichever is later; do a 
detailed inspection for cracking of each rear mount strut in the 
left and right engine nacelles.

    Note 1:  Bombardier Service Bulletin 8-71-24, dated August 21, 
2001, does not contain inspection procedures for the detailed 
inspection required by paragraph (a) of this AD; however, the 
definition of a detailed inspection is specified in Note 2 of this 
AD.


    Note 2:  For the purposes of this AD, a detailed inspection is 
defined as: ``An intensive visual examination of a specific 
structural area, system, installation, or assembly to detect damage, 
failure, or irregularity. Available lighting is normally 
supplemented with a direct source of good lighting at intensity 
deemed appropriate by the inspector. Inspection aids such as mirror, 
magnifying lenses, etc., may be used. Surface cleaning and elaborate 
access procedures may be required.''

    (1) If no crack is found, repeat the inspection at intervals not 
to exceed 250 flight hours, until accomplishment of paragraph (b) of 
this AD.
    (2) If any crack is found, before further flight, replace the 
strut with a new, improved strut per Bombardier Service Bulletin 8-
71-24, dated August 21, 2001. Repeat the inspection thereafter at 
intervals not to exceed 50 flight hours, for that nacelle only.

Optional Terminating Action

    (b) Replacement of both rear mount struts in a nacelle with new, 
improved struts, by doing all the actions specified in the Job Set-
up, Procedure, and Close-out sections of the Accomplishment 
Instructions of Bombardier Service Bulletin 8-71-24, dated August 
21, 2001, ends the repetitive inspections required by this AD for 
that nacelle only. Replacement of both rear mount struts on both the 
left and right engine nacelles ends the repetitive inspections 
required by this AD.

Parts Installation

    (c) As of the effective date of this AD, no person shall install 
an engine rear mount strut, P/N 87110016-001, -003, -005, -007, -
009, or -011, on any airplane.

Alternative Methods of Compliance

    In accordance with 14 CFR 39.19, the Manager, New York Aircraft 
Certification Office, FAA, is authorized to approve alternative 
methods of compliance for this AD.

Incorporation by Reference

    (e) Unless otherwise provided in this AD, the actions shall be 
done in accordance with Bombardier Service Bulletin 8-71-24, dated 
August 21, 2001. This incorporation by reference was approved by the 
Director of the Federal Register in accordance with 5 U.S.C. 522(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 3: The subject of this AD is addressed in Canadian 
airworthiness directive CF-2001-20, dated May 16, 2001.

Effective Date

    (f) This amendment becomes effective on January 22, 2004.

    Issued in Renton, Washington, on December 5, 2003.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-31058 Filed 12-17-03; 8:45 am]
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