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Proposed Rule

Airworthiness Directives; Bombardier, Inc. Model DHC-8-400 Series Airplanes

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Information about this document as published in the Federal Register.

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Start Preamble

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:

Several operators have reported pitch oscillations and/or elevator asymmetry caution lights illumination when flying with the autopilot engaged. Investigations revealed that loose rivets in the torque tube assemblies caused relative motion between the crank arms and torque tubes.

Loose rivets could result in excessive wear and subsequent significant backlash in the driving crank arms. This condition, if left uncorrected, will progressively get worse and degrade the controllability of the aeroplane.

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 June 27, 2011.

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.

For service information identified in this proposed AD, contact Bombardier, Inc., Q-Series Technical Help Desk, 123 Garratt Boulevard, Toronto, Ontario M3K 1Y5, Canada; telephone 416-375-4000; fax 416-375-4539; e-mail thd.qseries@aero.bombardier.com; Internet http://www.bombardier.com. You may review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221.

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.

Start Further Info

FOR FURTHER INFORMATION CONTACT:

Cathy Nguyen-Quoc, Aerospace Engineer, Airframe and Mechanical Systems Branch, ANE-171, FAA, New York Aircraft Certification Office, 1600 Stewart Avenue, Suite 410, Westbury, New York 11590; telephone (516) 228-7323; fax (516) 794-5531.

End Further Info End Preamble Start Supplemental Information

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-2011-0471; Directorate Identifier 2010-NM-219-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-2010-27, dated August 20, 2010 (referred to after this as “the MCAI”), to correct an unsafe condition for the specified products. The MCAI states:

Several operators have reported pitch oscillations and/or elevator asymmetry caution lights illumination when flying with the autopilot engaged. Investigations revealed that loose rivets in the torque tube assemblies caused relative motion between the crank arms and torque tubes.

Loose rivets could result in excessive wear and subsequent significant backlash in the driving crank arms. This condition, if left uncorrected, will progressively get worse and degrade the controllability of the aeroplane.

Required actions include doing an inspection for the part number of the left and right elevator torque tube assemblies and, if necessary, replacing the elevator torque tube assembly or replacing the elevator torque tube rivets, and re-identifying the assemblies. You may obtain further information by examining the MCAI in the AD docket.

Relevant Service Information

Bombardier Inc., has issued Service Bulletin 84-27-50, Revision C, dated July 26, 2010. The actions described in this service information are intended to Start Printed Page 27618correct 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 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 66 products of U.S. registry. We estimate the following costs to comply with this proposed AD:

Estimated Costs

ActionLabor costParts costCost per productCost on U.S. operators
Inspection2 × $85 per hour = $170None$170$11,220

We estimate the following costs to do any necessary replacements that would be required based on the results of the proposed inspection. We have no way of determining the number of aircraft that might need these replacements:

On-Condition Costs

ActionLabor costParts costCost per product
Replace left torque tube15 work-hours × $85 per hour = $1,275$4,354$5,629
Replace right torque tube15 work-hours × $85 per hour = $1,2755,9137,188

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.

Start List of Subjects

List of Subjects in 14 CFR Part 39

End List of Subjects

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

Start Part

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Start Authority

Authority: 49 U.S.C. 106(g), 40113, 44701.

End Authority
[Amended]

2. The FAA amends § 39.13 by adding the following new AD:

Bombardier, Inc.: Docket No. FAA-2011-0471; Directorate Identifier 2010-NM-219-AD.

Comments Due Date

(a) We must receive comments by June 27, 2011.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Bombardier, Inc. Model DHC-8-400, -401, and -402 airplanes; certificated in any category; serial numbers 4001 through 4305 inclusive.

Subject

(d) Air Transport Association (ATA) of America Code 27: Flight controls.

Reason

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

Several operators have reported pitch oscillations and/or elevator asymmetry Start Printed Page 27619caution lights illumination when flying with the autopilot engaged. Investigations revealed that loose rivets in the torque tube assemblies caused relative motion between the crank arms and torque tubes.

Loose rivets could result in excessive wear and subsequent significant backlash in the driving crank arms. This condition, if left uncorrected, will progressively get worse and degrade the controllability of the aeroplane.

Compliance

(f) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

Inspection for Part Number

(g) At the applicable times identified in paragraphs (g)(1) and (g)(2) of this AD, do an inspection to determine the part numbers of the left and right elevator torque tubes, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84-27-50, Revision C, dated July 26, 2010. A review of airplane maintenance records is acceptable in lieu of this inspection if the part numbers of the left and right elevator torque tubes can be conclusively determined from that review.

(1) For airplanes that have accumulated 8,000 or more total flight hours as of the effective date of this AD: Within 2,000 flight hours after the effective date of this AD.

(2) For airplanes that have accumulated less than 8,000 total flight hours as of the effective date of this AD: Within 6,000 flight hours after the effective date of this AD, but before the accumulation of 10,000 total flight hours.

Corrective Actions

(h) If, as a result of the inspection required by paragraph (g) of this AD, any left elevator torque tube has part number (P/N) 82760709-009, at the applicable time in paragraph (g)(1) or (g)(2) of this AD, do the actions in paragraph (h)(1) or (h)(2) of this AD.

(1) Replace the elevator torque tube with a new elevator torque tube having P/N 82760709-011, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84-27-50, Revision C, dated July 26, 2010.

(2) Replace the rivets in each elevator torque tube assembly with Hi Lite pins having P/N B0206001AG8 and collars having P/N HST1070CY, and re-identify the elevator torque tube assembly having P/N 82760709-009, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84-27-50, Revision C, dated July 26, 2010.

(i) If, as a result of the inspection required by paragraph (g) of this AD, any right elevator torque tube has P/N 82760757-009, at the applicable time in paragraph (g)(1) or (g)(2) of this AD, do the actions in paragraph (i)(1) or (i)(2) of this AD.

(1) Replace the elevator torque tube with a new elevator torque tube having P/N 82760757-011, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84-27-50, Revision C, dated July 26, 2010.

(2) Replace the rivets in each elevator torque tube assembly with Hi Lite pins having P/N B0206001AG8 and collars having P/N HST1070CY, and re-identify the elevator torque tube assembly having P/N 82760757-009, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84-27-50, Revision C, dated July 26, 2010.

Credit for Actions Accomplished in Accordance With Previous Service Information

(j) Actions done before the effective date of this AD, in accordance with the service bulletins listed in table 1 of this AD, are considered acceptable for compliance with the corresponding action specified in this AD.

Table 1—Credit Service Bulletins

Service BulletinRevisionDate
Bombardier Service Bulletin 84-27-50OriginalMarch 3, 2010.
Bombardier Service Bulletin 84-27-50AApril 28, 2010.
Bombardier Service Bulletin 84-27-50BMay 19, 2010.

Parts Installation

(k) As of the effective date of this AD, no person may install on any airplane an elevator torque tube assembly having P/N 82760709-009 or 82760757-009.

FAA AD Differences

Note 1:

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

Other FAA AD Provisions

(l) The following provisions also apply to this AD:

(1) Alternative Methods of Compliance (AMOCs): The Manager, New York Aircraft Certification Office (ACO), ANE-170, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the ACO, send it to ATTN: Program Manager, Continuing Operational Safety, FAA, New York ACO, 1600 Stewart Avenue, Suite 410, Westbury, New York 11590; telephone 516-228-7300; fax 516-794-5531. Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office. The AMOC approval letter must specifically reference this AD.

(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.

Related Information

(m) Refer to MCAI Canadian Airworthiness Directive CF-2010-27, dated August 20, 2010; and Bombardier Service Bulletin 84-27-50, Revision C, dated July 26, 2010; for related information.

Start Signature

Issued in Renton, Washington, on May 5, 2011.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. 2011-11605 Filed 5-11-11; 8:45 am]

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