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Proposed Rule

Airworthiness Directives; Dowty Propellers Type R321/4-82-F/8, R324/4-82-F/9, R333/4-82-F/12, and R334/4-82-F/13 Propeller Assemblies

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

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AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to revise an existing airworthiness directive (AD) that applies to the products listed above. The existing AD currently requires initial and repetitive ultrasonic inspections of propeller hubs, part number (P/N) 660709201. Since we issued that AD, Dowty Propellers introduced a new hub assembly P/N. This proposed AD would revise that AD by introducing as an optional terminating action for the initial and repetitive ultrasonic inspections of that AD, replacement of propeller hub P/N 660709201 with a new propeller hub, P/N 660717226. We are proposing this AD to prevent that same propeller hub failure due to cracks in the hub, which could result in loss of control of the airplane, and to introduce an optional terminating action.

DATES:

We must receive comments on this proposed AD by June 2, 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: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this AD, contact Dowty Propellers, Anson Business Park, Cheltenham Road East, Gloucester GL 29QN, UK; telephone: 44 (0) 1452 716000; fax: 44 (0) 1452 716001. You may review copies of the referenced service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call 781-238-7125.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov;​ or in person at the Docket Management Facility 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 Office (phone: 800-647-5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

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FOR FURTHER INFORMATION CONTACT:

Michael Schwetz, Aerospace Engineer, Boston Aircraft Certification Office, FAA, 12 New England Executive Park, Burlington, MA 01803; phone: 781-238-7761; fax: 781-238-7170; e-mail: michael.schwetz@faa.gov.

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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-2010-1270; Directorate Identifier 2001-NE-50-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 because of 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

On December 2, 2005, we issued AD 2005-25-10, Amendment 39-14403 (70 FR 73364, December 12, 2005), for Dowty Propellers type R321/4-82-F/8, R324/4-82-F/9, R333/4-82-F/12, and R334/4-82-F/13 propeller assemblies. That AD requires initial and repetitive ultrasonic inspections of propeller hubs, P/N 660709201. That AD resulted from a report of a hub separation on a CASA 212 airplane, and mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. We issued that AD to prevent propeller hub failure due to cracks in the hub, which could result in loss of control of the airplane.

Actions Since Existing AD Was Issued

Since we issued AD 2005-25-10, the European Aviation Safety Agency (EASA) has issued AD 2010-0196R1, dated November 12, 2010, which requires initial and repetitive ultrasonic inspections of propeller hubs, and introduces a new P/N propeller hub as optional terminating action to the inspections.

Relevant Service Information

We have reviewed the technical contents of Dowty Propellers Alert Service Bulletin (SB) No. 61-1119, Revision 5, dated July 1, 2009, Alert SB No. 61-1124, Revision 2, dated August 25, 2010, Alert SB No. 61-1125, Revision 2, dated August 25, 2010, and Alert SB No. 61-1126, Revision 2, dated August 25, 2010. The SBs describe procedures for initial and repetitive ultrasonic inspections of the rear wall of the rear half of the propeller hub for cracks on types R334/4-82-F/13, R333/4-82-F/12, R321/4-82-F/8, and R324/4-82-F/9 propeller assemblies, respectively. The SBs also introduce new hub assembly P/N 660717226, as optional terminating action for the initial and repetitive inspections. EASA Start Printed Page 21676classified the service information as mandatory and issued AD 2010-0196R1, dated November 12, 2010, to ensure the airworthiness of these propeller assemblies in Europe.

Bilateral Agreement Information

These propeller assemblies are manufactured in the United Kingdom, and are type certificated for operation in the United States under the provisions of Section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Under this bilateral airworthiness agreement, EASA kept us informed of the situation described above. We have examined the findings of the EASA, reviewed all available information, and determined that AD action is necessary for products of these type designs that are certificated for operation in the United States.

FAA's Determination

We are proposing this AD revision because we evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of these same type designs.

Proposed AD Requirements

This proposed AD would retain the inspection requirements of AD 2005-25-10. This proposed AD would introduce the installation of a new P/N hub assembly as optional terminating action to the inspections. This proposed AD would also eliminate the inspection reporting requirements, since we have already collected sufficient data.

Differences Between the Proposed AD and the Service Information or MCAI

Although Appendix A of Alert SB No. 61-1119, Revision 5, dated July 1, 2009, requires reporting the inspection data to Dowty Propellers, this proposed AD would not require any reporting.

Although the MCAI uses initial inspection compliance times of 20 days/60 days, we removed them from the proposed AD, since the unsafe condition is not related to corrosion.

Costs of Compliance

We estimate that this proposed AD would affect 132 propellers installed on airplanes of U.S. registry. We also estimate that it would take about 0.5 work-hour per propeller to perform the proposed inspection and about 1 hour to replace a propeller hub. The average labor rate is $85 per work-hour. Required parts would cost about $19,500 per engine. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $2,590,830.

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 have 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 that the 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),

(3) Will not affect intrastate aviation in Alaska, and

(4) 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.

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List of Subjects in 14 CFR Part 39

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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:

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

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[Amended]

2. The FAA amends § 39.13 by removing airworthiness directive (AD) 2005-25-10, Amendment 39-14403 (70 FR 73364, December 12, 2005), and adding the following new AD:

Dowty Propellers (formerly Dowty Aerospace; Dowty Rotol Limited; and Dowty Rotol): Docket No. FAA-2010-1270; Directorate Identifier 2001-NE-50-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by June 2, 2011.

Affected ADs

(b) This AD revises AD 2005-25-10, Amendment 39-14403.

Applicability

(c) This AD applies to Dowty Propellers Type R321/4-82-F/8, R324/4-82-F/9, R333/4-82-F/12, and R334/4-82-F/13 propeller assemblies with propeller hubs part number (P/N) 660709201.

Unsafe Condition

(d) This AD was prompted by the need to introduce an optional terminating action for the repetitive inspections. We are issuing this AD to prevent propeller hub failure due to cracks in the hub, which could result in loss of control of the airplane, and to introduce an optional terminating action.

Compliance

(e) Comply with this AD within the compliance times specified, unless already done.

Initial Ultrasonic Inspections

(f) Perform an initial ultrasonic inspection of the rear wall of the rear half of the propeller hub for cracks within the compliance time specified in Table 1 of this AD. Use Appendix A or Appendix D of the applicable Dowty Alert Service Bulletin (SB) listed in Table 1 of this AD to do the inspection.Start Printed Page 21677

Table 1—Applicable Alert SB for Propeller Type

Propeller assembly typeInitial inspection withinRepeat inspection withinApplicable SB
(1) R334/4-82-F/1310 flight hours (FH) time-in-service (TIS) after the effective date of this AD300 FH time-since-last-inspection (TSLI) or 300 flight cycles-since-last inspection, whichever occurs soonerAlert SB No. 61-1119, Revision 5, dated July 1, 2009.
(2) R321/4-82-F/850 FH TIS after the effective date of this AD1,000 FH TSLIAlert SB No. 61-1125, Revision 2, dated August 25, 2010.
(3) R324/4-82-F/950 FH TIS after the effective date of this AD1,000 FH TSLIAlert SB No. 61-1126, Revision 2, dated August 25, 2010.
(4) R333/4-82-F/1250 FH TIS after the effective date of this AD1,000 FH TSLIAlert SB No. 61-1124, Revision 2, dated August 25, 2010.

(g) For hubs and propellers in storage, perform an initial ultrasonic inspection of the rear wall of the rear half of the propeller hub for cracks, before placing in service. Use Appendix A or Appendix D of the applicable Dowty Alert SB listed in Table 1 of this AD to do the inspection.

Initial Inspection—Previous Credit

(h) Propeller hubs, P/N 660709201, that previously passed inspection using Dowty Alert SBs listed in Table 1 of this AD or an earlier issue of those SBs, have satisfied the initial inspection requirements of this AD. However, you must comply with the repetitive inspection requirements found in this AD.

Repetitive Ultrasonic Inspections

(i) Thereafter, perform a repetitive ultrasonic inspection of the rear wall of the rear half of the propeller hub for cracks within the compliance time specified in Table 1 of this AD. Use Appendix A or Appendix D of the applicable Dowty Alert SB listed in Table 1 of this AD to do the inspection.

Optional Terminating Action

(j) As optional terminating action for the repetitive inspections required by this AD, replace propeller hub, P/N 660709201, with a new propeller hub, P/N 660717226.

Alternative Methods of Compliance (AMOCs)

(k) The Manager, Boston Certification Office, has the authority to approve AMOCs for this AD if requested using the procedures found in 14 CFR 39.19.

Related Information

(l) For more information about this AD, contact Michael Schwetz, Aerospace Engineer, Boston Aircraft Certification Office, FAA, 12 New England Executive Park, Burlington, MA 01803; phone: 781-238-7761; fax: 781-238-7170; e-mail: michael.schwetz@faa.gov.

(m) European Aviation Safety Agency 2010-0196R1, dated November 12, 2010, pertains to the subject of this AD.

(n) For service information identified in this AD, contact Dowty Propellers, Anson Business Park, Cheltenham Road East, Gloucester GL 29QN, UK; telephone: 44 (0) 1452 716000; fax: 44 (0) 1452 716001. You may review copies of the referenced service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call 781-238-7125.

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Issued in Burlington, Massachusetts, on April 7, 2011.

Peter A. White,

Acting Manager, Engine & Propeller Directorate, Aircraft Certification Service.

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[FR Doc. 2011-9258 Filed 4-15-11; 8:45 am]

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