Document ID: FAA-2007-0183-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; Bombardier Model DHC-8-400 Series Airplanes
Posted Date: 2007-11-13T05:00Z

[Federal Register: November 13, 2007 (Volume 72, Number 218)]
[Proposed Rules]               
[Page 63827-63829]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr13no07-14]                         

========================================================================
Proposed Rules
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains notices to the public of 
the proposed issuance of rules and regulations. The purpose of these 
notices is to give interested persons an opportunity to participate in 
the rule making prior to the adoption of the final rules.

========================================================================

[[Page 63827]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-0183; Directorate Identifier 2007-NM-146-AD]
RIN 2120-AA64

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

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: We propose to adopt a new airworthiness directive (AD) for the 
products listed above. This proposed 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.

The proposed AD would require actions that are intended to address the 
unsafe condition described in the MCAI.

DATES: We must receive comments on this proposed AD by December 13, 
2007.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov.
 Follow the instructions for submitting comments.

     Fax: (202) 493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-40, 1200 New 
Jersey Avenue, SE., Washington, DC, between 9 a.m. and 5 p.m., Monday 
through Friday, except Federal holidays.

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 this proposed AD, 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.

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: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2007-0183; 
Directorate Identifier 2007-NM-146-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD based on those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov
, including any personal information you provide. We 

will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    Transport Canada Civil Aviation (TCCA), which is the aviation 
authority for Canada, has issued Canadian Airworthiness Directive CF-
2007-05, effective April 24, 2007 (referred to after this as ``the 
MCAI''), 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.

Relevant Service Information

    Bombardier has issued Service Bulletin 84-52-51, Revision A, dated 
September 8, 2006, including Service Bulletin 8-MHI0084, Revision C, 
dated September 6, 2006; and Repair Drawing RD 8/4-52-202, Issue 1, 
dated December 2, 2005. The actions described in this service 
information are intended to correct the unsafe condition identified in 
the MCAI.

FAA's Determination and Requirements of This Proposed AD

    This product has been approved by the aviation authority of another 
country, and is approved for operation

[[Page 63828]]

in the United States. Pursuant to our bilateral agreement with the 
State of Design Authority, we have been notified of the unsafe 
condition described in the MCAI and service information referenced 
above. We are proposing this AD because we evaluated all pertinent 
information and determined an unsafe condition exists and is likely to 
exist or develop on other products of the same type design.

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 proposed different actions in this AD from those 
in the MCAI in order to follow FAA policies. Any such differences are 
highlighted in a NOTE within the proposed AD.

Costs of Compliance

    Based on the service information, we estimate that this proposed AD 
would affect about 29 products of U.S. registry. We also estimate that 
it would take about 5 work-hours per product to comply with the basic 
requirements of this proposed AD. The average labor rate is $80 per 
work-hour. Required parts would 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 costs. 
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 the proposed AD on 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.

Regulatory Findings

    We determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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 proposed 
regulation:
    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 proposed AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

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

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

Comments Due Date

    (a) We must receive comments by December 13, 2007.

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: Doors.

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

[[Page 63829]]

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 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 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.

    Issued in Renton, Washington, on November 5, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E7-22103 Filed 11-9-07; 8:45 am]

BILLING CODE 4910-13-P