AD 2008-04-04

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 theunsafe condition on these products.

Final rule.

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 anincrease 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 toexceed 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 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 inthis 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.

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 flightof 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 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

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFRpart 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: