E9-11478. Airworthiness Directives; Dowty Propellers Models R354/4-123-F/13, R354/4-123-F/20, R375/4-123-F/21, R389/4-123-F/25, R389/4-123-F/26, and R390/4-123-F/27 Propellers

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Supplemental notice of proposed rulemaking (NPRM); reopening of the comment period.

SUMMARY:

This supplemental NPRM revises an earlier proposed airworthiness directive (AD), applicable to Dowty Propellers Models R354/4-123-F/13, R354/4-123-F/20, R375/4-123-F/21, R389/4-123-F/25, R389/4-123-F/26, and R390/4-123-F/27 propellers. That proposed AD would have required initial and repetitive visual inspections of propeller blade root outer sleeves for cracks, and removal before further flight of propeller blades with cracked blade root outer sleeves. That proposed AD resulted from mandatory continuing airworthiness information (MCAI) issued by the European Aviation Safety Agency (EASA) to identify and correct an unsafe condition on certain Dowty propellers. This supplemental NPRM revises the proposed AD to correct the listing of propeller models affected. This supplemental NPRM results from the discovery that we need to correct one of the propeller model numbers affected, and to remove an erroneous propeller model number. We are proposing this AD to prevent blade counterweight release, which could result in injury or damage to the airplane. The MCAI describes the unsafe condition as:

A number of propeller blade outer sleeves have been found with cracks since 1996. Testing has shown that blade retention integrity is not affected by this cracking. However, this condition, if not detected and corrected, can lead to blade counterweight release, possibly resulting in damage to the aircraft and injury to occupants or persons on the ground.

We are proposing this AD to prevent blade counterweight release, which could result in injury or damage to the airplane.

DATES:

We must receive comments on this proposed AD by June 17, 2009.

ADDRESSES:

You may send comments by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.
• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.
• Fax: [phone].

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 [phone]) is the same as the Mail address provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Terry Fahr, Aerospace Engineer, Boston Aircraft Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: [e-mail]; telephone [phone]; fax [phone].

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-2008-0545; Directorate Identifier 2008-NE-16-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 with FAA personnel concerning this proposed AD. Using the search function of the Web site, anyone can find and read the comments in any of our dockets, including, if provided, the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78).

Discussion

EASA, which is the Technical Agent for the Member States of the European Community, has issued EASA AD 2008-0033, dated February 19, 2008, to correct an unsafe condition for the specified products. The EASA AD states:

A number of propeller blade outer sleeves have been found with cracks since 1996. Testing has shown that blade retention integrity is not affected by this cracking. However, this condition, if not detected and corrected, can lead to blade counterweight release, possibly resulting in damage to the aircraft and injury to occupants or persons on the ground.

You may obtain further information by examining the MCAI in the AD docket.

Relevant Service Information

Dowty Propellers has issued Alert Service Bulletin No. SF340-61-A106, Revision 1, dated March 20, 2008. 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 the United Kingdom, and is approved for operation in the United States. Pursuant to our bilateral agreement with the United Kingdom, they have notified us of the unsafe condition described in the MCAI and service information referenced above. We are proposing this AD because we evaluated all information provided by EASA and determined the unsafe condition exists and is likely to exist or develop on other products of the same type design. This Supplemental NPRM requires initial and repetitive visual inspections of propeller blade root outer sleeves for cracks, and removal before further flight of propeller blades with cracked blade root outer sleeves.

Comments

We gave the public the opportunity to participate in developing this AD. We considered the comments received on the original NPRM.

Request To Reference the Latest Service Bulletin

One commenter, Colgan Air, requests that we reference the latest service bulletin, which is Dowty Propellers Alert Service Bulletin No. SF340-61-A106, Revision 1, dated March 20, 2008.

We agree and changed that reference in this Supplemental NPRM.

Request To Clarify Airplane Manufacturer

One commenter, SAAB AB, SAAB Aerosystems, requests that we clarify that “340B airplanes” should be referred to as “SAAB 340B airplanes”.

We agree and clarified that reference in this Supplemental NPRM.

Need To Correct the Listing of Propeller Models Affected

We discovered the need to correct the listing of the propeller models affected that was included in the original NPRM published in the Federal Register on June 30, 2008 (73 FR 36819). That listing, which is Dowty Propellers models R354/4-123-F/13, R354/4-123-F/20, R354/4-123-F/21, R375/4-123-F/21, R389/4-123-F/25, R354/4-123-F/26, and R390/4-123-F/27 propellers, is changed in this Supplemental NPRM to Dowty Propellers Models R354/4-123-F/13, R354/4-123-F/20, R375/4-123-F/21, R389/4-123-F/25, R389/4-123-F/26, and R390/4-123-F/27 propellers.

Conclusion

We reviewed the available data, including the comments received, and determined that air safety and the public interest require making the changes described previously. We determined that these changes will not increase the economic burden on any operator or increase the scope of the Supplemental NPRM.

Costs of Compliance

Based on the service information, we estimate that this proposed AD would affect about 292 propellers installed on airplanes of U.S. registry. We also estimate that it would take 0.5 work-hour per propeller to visually inspect for cracks. The average labor rate is $80 per work hour. Based on these figures, we estimate the cost of the proposed AD on U.S. operators to be $11,680.

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.

§ 39.13

[Amended]

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

Dowty Propellers: Docket No. FAA-2008-0545; Directorate Identifier 2008-NE-16-AD.

Comments Due Date

(a) We must receive comments by June 17, 2009.

Affected Airworthiness Directives (ADs)

(b) None.

Applicability

(c) This AD applies to Dowty Propellers Models R354/4-123-F/13, R354/4-123-F/20, R375/4-123-F/21, R389/4-123-F/25, R389/4-123-F/26, and R390/4-123-F/27 propellers. These propellers are installed on, but not limited to, Saab AB, Saab Aerosystems SF340A and SAAB SF340B airplanes.

Reason

(d) European Aviation Safety Agency (EASA) AD No. 2008-0033, dated February 19, 2008, states:

A number of propeller blade outer sleeves have been found with cracks since 1996. Testing has shown that blade retention integrity is not affected by this cracking. However, this condition, if not detected and corrected, can lead to blade counterweight release, possibly resulting in damage to the aircraft and injury to occupants or persons on the ground.

This AD requires initial and repetitive visual inspections of propeller blade root outer sleeves for cracks, and removal before further flight of propeller blades with cracked blade root outer sleeves. We are issuing this AD to prevent blade counterweight release, which could result in injury or damage to the airplane.

Actions and Compliance

(e) Unless already done, do the following actions.

Propeller Blade Root Outer Sleeve Visual Inspections

(1) At the next 1,600 flight hours (FH) aircraft check after the effective date of this AD, or, after any blade accumulates 15,000 FH time-in-service, whichever occurs later, visually inspect all propeller blade root outer sleeves for cracks.

(2) Thereafter, at intervals not to exceed 1,600 FH, visually inspect all propeller blade root outer sleeves for cracks.

(3) Before further flight, remove any propeller blades found with cracked root outer sleeves during the visual inspections in paragraphs (e)(1) and (e)(2) of this AD.

FAA AD Differences

(f) None.

Alternative Methods of Compliance (AMOCs)

(g) The Manager, Boston Aircraft Certification Office, FAA, Engine and Propeller Directorate, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19.

Related Information

(h) Refer to European Aviation Safety Agency AD 2008-0033, dated February 19, 2008, and Dowty Propellers Alert Service Bulletin No. SF340-61-A106, Revision 1, dated March 20, 2008, for related information.

(i) Contact Terry Fahr, Aerospace Engineer, Boston Aircraft Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: [e-mail]; telephone [phone]; fax [phone], for more information about this AD.

Issued in Burlington, Massachusetts, on May 8, 2009.

Peter A. White,

Assistant Manager, Engine and Propeller Directorate, Aircraft Certification Service.