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Proposed Rule

Airworthiness Directives; Bombardier, Inc. Model DHC-8-400, -401, and -402 Airplanes

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Information about this document as published in the Federal Register.

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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 that would supersede an existing AD. 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 cases have been reported where a loss of fluid in the No. 2 hydraulic system has caused the power transfer unit (PTU) to overspeed, resulting in pressure fluctuations and increased fluid flow within the No. 1 hydraulic system. In one case, the hydraulic system control logic did not shut down the PTU and the overspeed condition persisted, resulting in the illumination of the No. 1 HYD FLUID HOT caution light.

* * * * *

The unsafe condition is possible loss of both the No. 1 and No. 2 hydraulic systems, resulting in the potential loss of several functions essential for safe flight and landing of the airplane. 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 7, 2010.

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., 400 Côte-Vertu Road West, Dorval, Québec H4S 1Y9, Canada; telephone 514-855-5000; fax 514-855-7401; 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:

Fabio Buttitta, 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) 228-7303; 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-2010-0382; Directorate Identifier 2009-NM-211-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 have lengthened the 30-day comment period for proposed ADs that address MCAI originated by aviation authorities of other countries to provide adequate time for interested parties to submit comments. The comment period for these proposed ADs is now typically 45 days, which is consistent with the comment period for domestic transport ADs.

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

On July 31, 2008, we issued AD 2008-17-06, Amendment 39-15644 (73 FR 47818, August 15, 2008). That AD required actions intended to address an unsafe condition on the products listed above.

Since we issued AD 2008-17-06, a modification of the power transfer unit (PTU) control logic, including the provision of automatic PTU shutdown in the event of loss of fluid in the No. 2 hydraulic system, has been developed. The modification addresses the identified unsafe condition. In addition, the applicability has been revised to remove airplanes having serial number 4185 and subsequent, since an equivalent modification has been installed in production on these airplanes. Transport Canada Civil Aviation (TCCA), which is the aviation authority for Canada, has issued Canadian Airworthiness Directive CF-2006-08R1, dated August 31, 2009 (referred to after this as “the MCAI”), to correct an unsafe condition for the specified products. The MCAI states:

Several cases have been reported where a loss of fluid in the No. 2 hydraulic system has caused the power transfer unit (PTU) to overspeed, resulting in pressure fluctuations and increased fluid flow within the No. 1 hydraulic system. In one case, the hydraulic system control logic did not shut down the PTU and the overspeed condition persisted, resulting in the illumination of the No.1 HYD FLUID HOT caution light.Start Printed Page 20788

As an interim action to avoid possible loss of both the No. 1 and No. 2 hydraulic systems, the Airplane Flight Manual (AFM) has been revised to include pulling the HYD PWR XFER circuit breaker in the event of the loss of all hydraulic fluid in the No. 2 hydraulic system.

Insertion of the resultant Temporary Amendment (TA) No. 13 into the AFM was mandated in the original issue of this [Canadian] directive. This instruction * * * remains in effect until * * * this [revised] directive is accomplished.

Revision 1 of this directive * * * mandates modification of the PTU control logic, including the provision of automatic PTU shutdown in the event of loss of fluid in the No. 2 hydraulic system. In addition, the applicability of the [Canadian] directive has been revised to remove aircraft Serial Number (SN) 4185 and subsequent, since an equivalent modification has been installed in production on these aircraft.

The unsafe condition is possible loss of both the No. 1 and No. 2 hydraulic systems, resulting in the potential loss of several functions essential for safe flight and landing of the airplane. You may obtain further information by examining the MCAI in the AD docket.

Relevant Service Information

Bombardier has issued Service Bulletin 84-29-22, Revision A, dated February 24, 2009. 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 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 42 products of U.S. registry.

The actions that are required by AD 2008-17-06 and retained in this proposed AD take up about 1 work-hour per product, at an average labor rate of $85 per work hour. Required parts cost about $0 per product. Based on these figures, the estimated cost of the currently required actions is up to $85 per product.

We estimate that it would take up to 165 work-hours per product to comply with the new basic requirements of this proposed AD. The average labor rate is $85 per work-hour. Required parts would cost about $10,982 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 modification on U.S. operators to be up to $1,050,294, or up to $25,007 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.

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:

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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 removing Amendment 39-15644 (73 FR 47818, August 15, 2008) and adding the following new AD:

Bombardier, Inc.: Docket No. FAA-2010-0382; Directorate Identifier 2009-NM-211-AD.

Comments Due Date

(a) We must receive comments by June 7, 2010.

Affected ADs

(b) This AD supersedes AD 2008-17-06, Amendment 39-15644.

Applicability

(c) This AD applies to Bombardier, Inc. Model DHC-8-400, -401, and -402 airplanes, certificated in any category; serial numbers 4001, 4003, 4004, 4006, and 4008 through 4184 inclusive.

Subject

(d) Air Transport Association (ATA) of America Code 29: Hydraulic power.

Reason

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

“Several cases have been reported where a loss of fluid in the No.2 hydraulic system has caused the power transfer unit (PTU) to Start Printed Page 20789overspeed, resulting in pressure fluctuations and increased fluid flow within the No. 1 hydraulic system. In one case, the hydraulic system control logic did not shut down the PTU and the overspeed condition persisted, resulting in the illumination of the No.1 HYD FLUID HOT caution light.

“As an interim action to avoid possible loss of both the No. 1 and No. 2 hydraulic systems, the Airplane Flight Manual (AFM) has been revised to include pulling the HYD PWR XFER circuit breaker in the event of the loss of all hydraulic fluid in the No. 2 hydraulic system.

“Insertion of the resultant Temporary Amendment (TA) No. 13 into the AFM was mandated in the original issue of this [Canadian] directive. This instruction * * * remains in effect until * * * this [revised] directive is accomplished.

“Revision 1 of this directive * * * mandates modification of the PTU control logic, including the provision of automatic PTU shutdown in the event of loss of fluid in the No. 2 hydraulic system. In addition, the applicability of the [Canadian] directive has been revised to remove aircraft Serial Number (SN) 4185 and subsequent, since an equivalent modification has been installed in production on these aircraft.”

The unsafe condition is possible loss of both the No. 1 and No. 2 hydraulic systems, resulting in the potential loss of several functions essential for safe flight and landing of the airplane.

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.

Restatement of Requirements of AD 2007-12-03: Airplane Flight Manual (AFM) Revision

(g) Within 14 days after July 10, 2007 (the effective date of AD 2007-12-03, Amendment 39-15081, which was superseded by AD 2008-17-06), revise the Limitations section of the applicable AFM to include the information in the applicable Bombardier temporary amendment specified in Table 1 of this AD, as specified in the temporary amendment. These temporary amendments introduce procedures for pulling the “HYD PWR XFER” circuit breaker in the event of the loss of all hydraulic fluid in the No. 1 or No. 2 hydraulic system. Operate the airplane according to the limitations and procedures in the applicable temporary amendment.

Table 1—AFM Temporary Amendments

For Model—Use Bombardier Temporary Amendment—Issue—Dated—To Bombardier Dash 8 Q400 Airplane Flight Manual—
DHC-8-400 airplanes131July 14, 2005PSM 1-84-1A.
DHC-8-401 airplanes131July 14, 2005PSM 1-84-1A.
DHC-8-402 airplanes131July 14, 2005PSM 1-84-1A.

Note 1:

This may be done by inserting a copy of the applicable temporary amendment into the applicable AFM. When the applicable temporary amendment has been included in general revisions of the AFM, the general revisions may be inserted into the AFM, provided the relevant information in the general revisions is identical to that in the temporary amendment.

Restatement of Requirements of AD 2008-17-06: AFM Revision

(h) Within 14 days after September 2, 2008 (the effective date of AD 2008-17-06), revise the applicable AFM Normal and Abnormal Procedures section to include the information in the applicable Bombardier temporary amendment specified in Table 2 of this AD, as specified in the temporary amendment. These temporary amendments introduce additional procedures for ensuring that the “PTU CNTRL” switch is Normal, the “PTU CNTRL ON” advisory light is out, and the “HYD PWR XFER” circuit breaker is pulled in the event of the illumination of the “#2 HYD ISO VALVE” caution light. After accomplishing the AFM revision, the AFM limitation required by paragraph (g) in this AD may be removed from the AFM.

Table 2—AFM Temporary Amendments

For Model—Use Bombardier Temporary Amendment—Issue—Dated—To Bombardier Dash 8 Q400 Airplane Flight Manual—
DHC-8-400 airplanes133June 9, 2008PSM 1-84-1A.
DHC-8-401 airplanes133June 9, 2008PSM 1-84-1A.
DHC-8-402 airplanes133June 9, 2008PSM 1-84-1A.

New Requirements of This AD: Actions

(i) Within 6,000 flight hours after the effective date of this AD, modify the PTU control logic, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84-29-22, Revision A, dated February 24, 2009. Doing this modification terminates the requirements of paragraphs (g) and (h) of this AD, and after the modification has been done, the AFM limitation required by paragraphs (g) and (h) of this AD may be removed from the AFM.

(j) Modifying the PTU control logic is also acceptable for compliance with the requirements of paragraph (i) of this AD if done before the effective date of this AD, in accordance with Bombardier Service Bulletin 84-29-22, dated December 5, 2008.

FAA AD Differences

Note 2:

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

Other FAA AD Provisions

(k) 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. Send information 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 on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards 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. Start Printed Page 20790

(3) Reporting Requirements: For any reporting requirement in this AD, under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.), the Office of Management and Budget (OMB) has approved the information collection requirements and has assigned OMB Control Number 2120-0056.

Related Information

(l) Refer to MCAI Canadian Airworthiness Directive CF-2006-08R1, dated August 31, 2009; and Bombardier Service Bulletin 84-29-22, Revision A, dated February 24, 2009; for related information.

Start Signature

Issued in Renton, Washington, on April 9, 2010.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.

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[FR Doc. 2010-9110 Filed 4-20-10; 8:45 am]

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