Document ID: FAA-2007-0183-0008
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; Bombardier Model DHC-8-400 Series Airplanes
Posted Date: 2008-02-14T05:00Z

[Federal Register: February 14, 2008 (Volume 73, Number 31)]
[Rules and Regulations]               
[Page 8591-8593]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr14fe08-6]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-0183; Directorate Identifier 2007-NM-146-AD; 
Amendment 39-15376; AD 2008-04-04]
RIN 2120-AA64

 
Airworthiness Directives; Bombardier Model DHC-8-400 Series 
Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for the 
products listed above. This AD results from mandatory continuing 
airworthiness information (MCAI) originated by an aviation authority of 
another country to identify and correct an unsafe condition on an 
aviation product. The MCAI describes the unsafe condition as:

    There has been a reported case of failure of a bracket (P/N 
85217732-108) of the over-centering spring assembly inside the 
translating door of the forward baggage compartment. * * * Failure 
of the bracket caused the eyebolt at the bottom of the spring 
assembly to become loose, resulted in damage of the support beam 
during normal door handle movement. Damage of the support beam, 
which is dormant, in combination with failure of a doorstop attached 
to any remaining undamaged support beam will degrade the structural 
integrity of the door, resulting in possible depressurization or 
loss of the door.

We are issuing this AD to require actions to correct the unsafe 
condition on these products.

DATES: This AD becomes effective March 20, 2008.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of March 20, 
2008.

ADDRESSES: You may examine the AD docket on the Internet at http://
www.regulations.gov or in person at the U.S. Department of 
Transportation, Docket Operations, M-30, West Building Ground Floor, 
Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC.

FOR FURTHER INFORMATION CONTACT: Pong K. Lee, Aerospace Engineer, 
Airframe and Propulsion Branch, ANE-171, FAA, New York Aircraft 
Certification Office, 1600 Stewart Avenue, Suite 410, Westbury, New 
York 11590; telephone (516) 228-7324; fax (516) 794-5531.

SUPPLEMENTARY INFORMATION: 

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an AD that would apply to the specified products. 
That NPRM was published in the Federal Register on November 13, 2007 
(72 FR 63827). That NPRM proposed to correct an unsafe condition for 
the specified products. The MCAI states:

    There has been a reported case of failure of a bracket (P/N 
85217732-108) of the over-centering spring assembly inside the 
translating door of the forward baggage compartment. This condition 
can exist on other translating doors on the aircraft. Investigation 
concluded that an insufficient gap between the bottom eyebolt and 
the barrel of the spring assembly caused an increase of tension load 
on the bracket and resulted in subsequent failure of the bracket. 
Failure of the bracket caused the eyebolt at the bottom of the 
spring assembly to become loose, resulted in damage of the support 
beam during normal door handle movement. Damage of the support beam, 
which is dormant, in combination with failure of a doorstop attached 
to any remaining undamaged support beam will degrade the structural 
integrity of the door, resulting in possible depressurization or 
loss of the door.

Corrective actions include a one-time inspection for damage of the 
spring support bracket and support beam of the forward baggage door, 
aft service door, and aft passenger door; repetitive inspections for 
integrity (corrosion, damage, cracking, and looseness or misalignment) 
of the doorstops of support beams found to be within damage limits; 
repair of support beams, or replacement of damaged brackets, support 
beams, or doorstops, as applicable; and removal of certain washers and 
nuts. You may obtain further information by examining the MCAI in the 
AD docket.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We received no comments on the NPRM or on the determination of 
the cost to the public.

Conclusion

    We reviewed the available data and determined that air safety and 
the public interest require adopting the AD as proposed.

Differences Between This AD and the MCAI or Service Information

    We have reviewed the MCAI and related service information and, in 
general, agree with their substance. But we might have found it 
necessary to use different words from those in the MCAI to ensure the 
AD is clear for U.S. operators and is enforceable. In making these 
changes, we do not intend to differ substantively from the information 
provided in the MCAI and related service information.
    We might also have required different actions in this AD from those 
in the MCAI in order to follow our FAA policies. Any such differences 
are highlighted in a NOTE within the AD.

Costs of Compliance

    We estimate that this AD will affect about 29 products of U.S. 
registry. We also estimate that it will take about 5 work-hours per 
product to comply with the basic requirements of this AD. The average 
labor rate is $80 per work-hour. Required parts will cost about $0 per 
product. Where the service information lists required parts costs that 
are covered under warranty, we have assumed that there will be no 
charge for these parts. As we do not control warranty coverage for 
affected parties, some parties may incur costs higher than estimated 
here. Based on these figures, we estimate the cost of this AD to the 
U.S. operators to be $11,600, or $400 per product.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. ``Subtitle VII: Aviation 
Programs,'' describes in more detail the scope of the Agency's 
authority.
    We are issuing this rulemaking under the authority described in 
``Subtitle VII, Part A, Subpart III, Section 44701: General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

[[Page 8592]]

Regulatory Findings

    We determined that this AD will not have federalism implications 
under Executive Order 13132. This AD 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.
    For the reasons discussed above, I certify this AD:
    1. Is not a ``significant regulatory action'' under Executive Order 
12866;
    2. Is not a ``significant rule'' under the 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this AD and placed it in the AD docket.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Operations office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains the NPRM, the regulatory evaluation, 
any comments received, and other information. The street address for 
the Docket Operations office (telephone (800) 647-5527) is in the 
ADDRESSES section. Comments will be available in the AD docket shortly 
after receipt.

List of Subjects in 14 CFR Part 39

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

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 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. The FAA amends Sec.  39.13 by adding the following new AD:

2008-04-04 Bombardier, Inc. (Formerly de Havilland, Inc.): Amendment 
39-15376. Docket No. FAA-2007-0183; Directorate Identifier 2007-NM-
146-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective March 
20, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Bombardier Model DHC-8-400, DHC-8-401, 
and DHC-8-402 airplanes; certificated in any category; having serial 
numbers 4001 and 4003 through 4102.

Subject

    (d) Air Transport Association (ATA) of America Code 52:

Reason

    (e) The mandatory continuing airworthiness information (MCAI) 
states:

    There has been a reported case of failure of a bracket (P/N 
85217732-108) of the over-centering spring assembly inside the 
translating door of the forward baggage compartment. This condition 
can exist on other translating doors on the aircraft. Investigation 
concluded that an insufficient gap between the bottom eyebolt and 
the barrel of the spring assembly caused an increase of tension load 
on the bracket and resulted in subsequent failure of the bracket. 
Failure of the bracket caused the eyebolt at the bottom of the 
spring assembly to become loose, resulted in damage of the support 
beam during normal door handle movement. Damage of the support beam, 
which is dormant, in combination with failure of a doorstop attached 
to any remaining undamaged support beam will degrade the structural 
integrity of the door, resulting in possible depressurization or 
loss of the door.

Corrective actions include a one-time inspection for damage of the 
spring support bracket and support beam of the forward baggage door, 
aft service door, and aft passenger door; repetitive inspections for 
integrity (corrosion, damage, cracking, and looseness or 
misalignment) of the doorstops of support beams found to be within 
damage limits; repair of support beams, or replacement of damaged 
brackets, support beams, or doorstops, as applicable; and removal of 
certain washers and nuts.

Actions and Compliance

    (f) Unless already done, do the following actions.
    (1) Within 1,000 flight hours after the effective date of this 
AD, perform a one-time inspection for damage of the spring support 
bracket and support beams of the forward baggage door, aft service 
door, and aft passenger door, as applicable, in accordance with 
Bombardier Service Bulletin 84-52-51, Revision A, dated September 8, 
2006. Replace any damaged bracket, support beam, or doorstop in 
accordance with the service bulletin, prior to further flight.
    (i) If any support beam is damaged at only one spring location 
and the damage is within the limits defined in Bombardier Repair 
Drawing RD 8/4-52-202, Issue 1, dated December 2, 2005, do the 
actions specified in paragraphs (f)(1)(i)(A) and (f)(1)(i)(B) of 
this AD.
    (A) Inspect each doorstop of the affected door for integrity in 
accordance with the service bulletin prior to further flight, and 
repeat the inspection thereafter at intervals not to exceed 400 
flight hours, until the support beam is repaired as specified in 
paragraph (f)(1)(i)(B) of this AD or replaced in accordance with the 
service bulletin. If the doorstop does not meet integrity standards 
during any inspection required by this paragraph, before further 
flight, repair or replace the doorstop with a new or serviceable 
doorstop in accordance with the repair drawing.
    (B) Within 5,000 flight hours after accomplishing the inspection 
described in paragraph (f)(1) of this AD, repair the support beam in 
accordance with the repair drawing or replace in accordance with the 
service bulletin. Doing the repair or replacement terminates the 
inspections required by paragraph (f)(1)(i)(A) of this AD.
    (ii) If any support beam is damaged at one or two spring 
locations and any damage exceeds the limits defined in Bombardier 
Repair Drawing RD 8/4-52-202, Issue 1, dated December 2, 2005, prior 
to further flight, replace the damaged support beam with a new 
support beam in accordance with the service bulletin.
    (iii) If any support beam is damaged at two spring locations and 
the damage is within the limits defined in Bombardier Repair Drawing 
RD 8/4-52-202, Issue 1, dated December 2, 2005, prior to further 
flight, repair the support beam in accordance with the repair 
drawing.
    (2) Within 1,000 flight hours after the effective date of this 
AD, remove the nuts and washers at the bottom of the over-centering 
spring assemblies of the forward baggage door, aft service door, and 
aft passenger door by incorporating Modsum 4-155296, in accordance 
with Bombardier Service Bulletin 84-52-51, Revision A, dated 
September 8, 2006.

FAA AD Differences

    Note: This AD differs from the MCAI and/or service information 
as follows: No differences.

Other FAA AD Provisions

    (g) The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, New 
York Aircraft Certification Office (ACO), FAA, has the authority to 
approve AMOCs for this AD, if requested using the procedures found 
in 14 CFR 39.19. Send information to ATTN: Pong K. Lee, Aerospace 
Engineer, New York ACO, FAA, 1600 Stewart Avenue, Suite 410, 
Westbury, New York 11590; telephone (516) 228-7324; fax (516) 794-
5531. Before using any approved AMOC on any airplane to which the 
AMOC applies, notify your appropriate principal inspector (PI) in 
the FAA Flight Standards District Office (FSDO), or lacking a PI, 
your local FSDO.
    (2) Airworthy Product: For any requirement in this AD to obtain 
corrective actions from a manufacturer or other source, use these 
actions if they are FAA-approved. Corrective actions are considered 
FAA-approved if they are approved by the State of Design Authority 
(or their delegated agent). You are required to assure the product 
is airworthy before it is returned to service.
    (3) Reporting Requirements: For any reporting requirement in 
this AD, under the

[[Page 8593]]

provisions of the Paperwork Reduction Act, the Office of Management 
and Budget (OMB) has approved the information collection 
requirements and has assigned OMB Control Number 2120-0056.

Related Information

    (h) Refer to MCAI Canadian Airworthiness Directive CF-2007-05, 
effective April 24, 2007; Bombardier Service Bulletin 84-52-51, 
Revision A, dated September 8, 2006, including MHI Service Bulletin 
8-MHI0084, Revision C, dated September 6, 2006; and Bombardier 
Repair Drawing RD 8/4-52-202, Issue 1, dated December 2, 2005, for 
related information.

Material Incorporated by Reference

    (i) You must use Bombardier Service Bulletin 84-52-51, Revision 
A, dated September 8, 2006; and Bombardier Repair Drawing RD 8/4-52-
202, Issue 1, dated December 2, 2005; as applicable; to do the 
actions required by this AD, unless the AD specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) For service information identified in this AD, contact 
Bombardier, Inc., Bombardier Regional Aircraft Division, 123 Garratt 
Boulevard, Downsview, Ontario M3K 1Y5, Canada.
    (3) You may review copies at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue SW., Renton, Washington; or at the 
National Archives and Records Administration (NARA). For information 
on the availability of this material at NARA, call (202) 741-6030, 
or go to: http://www.archives.gov/federal-register/cfr/ibr-
locations.html.

    Issued in Renton, Washington, on February 7, 2008.
Kevin Hull,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E8-2626 Filed 2-13-08; 8:45 am]

BILLING CODE 4910-13-P