Federal Aviation Administration (FAA), DOT.
Notice of proposed rulemaking (NPRM).
We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) issued by the European Aviation Safety Agency (EASA) to identify and correct an unsafe condition on 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. 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 must receive comments on this proposed AD by July 30, 2008.
You may send comments by any of the following methods:
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You may examine the AD docket on the Internet at
Terry Fahr, Aerospace Engineer, Boston Aircraft Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803;
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
We will post all comments we receive, without change, to
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.
Dowty Propellers has issued Alert Service Bulletin No. SF340–61–A106, dated December 5, 2007. The actions described in this service information are intended to correct the unsafe condition identified in the MCAI.
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.
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.
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.
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.
Air transportation, Aircraft, Aviation safety, Safety.
Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:
1. The authority citation for part 39 continues to read as follows:
49 U.S.C. 106(g), 40113, 44701.
2. The FAA amends § 39.13 by adding the following new AD:
(a) We must receive comments by July 30, 2008.
(b) None.
(c) This AD applies to 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. These propellers are installed on, but not limited to, Saab AB, Saab Aerosystems SF340A and SF340B airplanes.
(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.
(e) Unless already done, do the following actions.
(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 cracked during the visual inspections in paragraphs (e)(1) and (e)(2) of this AD.
(f) None.
(g)
(h) Refer to European Aviation Safety Agency AD 2008–0033, dated February 19, 2008, and Dowty Propellers Alert Service Bulletin No. SF340–61–A106, dated December 5, 2007, 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: