Airworthiness Directives; Dowty Propellers Type R212/4-30-4/22 and R251/4-30-4/49 Propeller Assemblies

[Federal Register Volume 76, Number 193 (Wednesday, October 5, 2011)]
[Rules and Regulations]
[Pages 61558-61559]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-25653]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-0735; Directorate Identifier 2011-NE-01-AD; 
Amendment 39-16807; AD 2011-19-02]
RIN 2120-AA64


Airworthiness Directives; Dowty Propellers Type R212/4-30-4/22 
and R251/4-30-4/49 Propeller Assemblies

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for the 
products listed above. This AD results from mandatory continuing 
airworthiness information (MCAI) issued 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:

    Reports have been received from a small number of HS.748 
operators of finding cracks in the propeller hub port buttress 
threads of R212 and R251 propellers. The affected hubs had 
accumulated in excess of 6,000 flight hours. This condition, if not 
detected and corrected, could lead to propeller blade separation, 
possibly resulting in damage to the aeroplane and/or injury to 
persons on the ground.

We are issuing this AD to prevent propeller hub failure due to cracks 
in the hub, which could result in damage to the airplane.

DATES: This AD becomes effective November 9, 2011. The Director of the 
Federal Register approved the incorporation by reference of certain 
publications listed in this AD as of November 9, 2011.

ADDRESSES: The Docket Operations office is located at Docket Management 
Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, 
SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-
0001.

FOR FURTHER INFORMATION CONTACT: Michael Schwetz, Aerospace Engineer, 
Boston Aircraft Certification Office, FAA, Engine & Propeller 
Directorate, 12 New England Executive Park, Burlington, MA 01803; 
phone: 781-238-7761; fax: 781-238-7170; e-mail: 
[email protected].

SUPPLEMENTARY INFORMATION: 

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an AD that would apply to the specified products. 
That NPRM was published in the Federal Register on May 11, 2011 (76 FR 
27281). That NPRM proposed to correct an unsafe condition for the 
specified products. The MCAI states that:

    Reports have been received from a small number of HS.748 
operators of finding cracks in the propeller hub port buttress 
threads of R212 and R251 propellers. The affected hubs had 
accumulated in excess of 6,000 flight hours. This condition, if not 
detected and corrected, could lead to propeller blade separation, 
possibly resulting in damage to the aeroplane and/or injury to 
persons on the ground.

    The cracks originating from the root of the buttress threads in the 
blade ports are caused by high-cycle fatigue.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We received no comments on the NPRM published in the Federal 
Register on May 11, 2011 (76 FR 27281) or on the determination of the 
cost to the public.
    Since we published the NPRM in the Federal Register on May 11, 2011 
(76 FR 27281), we changed the AD Docket No. from FAA-2011-0033, to FAA-
2011-0735. The original number was inadvertently used both by the FAA 
Engine & Propeller Directorate, and the FAA Transport Airplane 
Directorate.
    Also since we published the NPRM in the Federal Register on May 11, 
2011 (76 FR 27281), we became aware that Dowty Propellers made minor 
changes to Alert Service Bulletin (ASB) No. 61-1043, Revision 6, and 
issued Revision 7, dated March 1, 2011. Revision 6 of the ASB had an 
incorrect Non-Destructive Testing (NDT) reference in Effectivity 
paragraph 1.D. We do not reference that paragraph in this AD, however, 
we changed the AD to reference the most current ASB, which is Revision 
7.

Conclusion

    We reviewed the available data and determined that air safety and 
the public interest require adopting the AD with the changes described 
previously. We determined that these changes will not increase the 
economic burden on any operator or increase the scope of the AD.

Costs of Compliance

    Based on the service information, we estimate that this AD will 
affect about 2 propellers installed on one airplane of U.S. registry. 
We also estimate that it will take about 1 work-hour per propeller to 
comply with this AD. The average labor rate is $85 per work-hour. 
Required parts will cost about $20,000 per propeller. Based on these 
figures, we estimate the cost of the AD on U.S. operators to be 
$40,170.

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 AD will not have federalism implications 
under Executive Order 13132. This AD will 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 AD:
    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 AD and placed it in the AD docket.

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.

[[Page 61559]]

and 5 p.m., Monday through Friday, except Federal holidays. The AD 
docket contains this AD, the regulatory evaluation, any comments 
received, and other information. The street address for the Docket 
Operations office (phone: (800) 647-5527) is provided in the ADDRESSES 
section. Comments will be available in the AD docket shortly after 
receipt.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

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

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

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


Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new AD:

2011-19-02 Dowty Propellers (formerly Dowty Aerospace; Dowty Rotol 
Limited; and Dowty Rotol): Amendment 39-16807. Docket No. FAA-2011-
0735; Directorate Identifier 2011-NE-01-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective November 
9, 2011.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Dowty Propellers type R212/4-30-4/22 
propeller assemblies with hub and driving center assembly part 
number (P/N) 601022105, 601022211, 601022294, 601021426, 601021858, 
or 601021859 installed, and type R251/4-30-4/49 propeller assemblies 
with hub and driving center assembly P/N 660207202 or P/N 660207203 
installed.

Reason

    (d) This AD results from 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 are issuing this AD to prevent propeller hub failure due 
to cracks in the hub, which could result in damage to the airplane.

Actions and Compliance

    (e) Unless already done, do the following:
    (1) Within 500 flight hours after the effective date of this AD, 
and thereafter at intervals not exceeding 500 flight hours, inspect 
the buttress threads in the propeller hub and driving center 
assembly for cracks.
    (2) Use paragraphs 2.A.(1) through 2.A.(4)(a) of Accomplishment 
Instructions of Dowty Propellers Alert Service Bulletin No. 61-1043, 
Revision 7, dated March 1, 2011, and NDT Technique NDT 175U 
(Appendix A of Dowty Propellers Alert Service Bulletin No. 61-1043, 
Revision 7, dated March 1, 2011), to do the inspection.
    (3) If a crack is found, remove the propeller assembly from 
service before further flight.
    (4) After the effective date of this AD, do not install this 
propeller on any airplane unless the propeller hub and driving 
center has passed the inspections required by this AD.

FAA AD Differences

    (f) This AD differs from the service information as follows:
    (1) Although the service bulletin tells you to return the 
affected parts to the manufacturer, this AD does not require that 
action.
    (2) Although the service bulletin tells you to submit 
information to the manufacturer, this AD does not require that 
action.

Alternative Methods of Compliance (AMOCs)

    (g) The Manager, Boston Aircraft Certification Office, FAA, 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 MCAI European Aviation Safety Agency AD 2011-0012, 
dated January 20, 2011, for related information.
    (i) Contact Michael Schwetz, Aerospace Engineer, Boston Aircraft 
Certification Office, FAA, Engine & Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; phone: 781-238-7761; 
fax: 781-238-7170, e-mail: [email protected] for more 
information about this AD.

Material Incorporated by Reference

    (j) You must use Dowty Propellers Alert Service Bulletin No. 61-
1043, Revision 7, dated March 1, 2011, to do the actions required by 
this AD, unless the AD specifies otherwise.
    (k) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (l) For service information identified in this AD, contact Dowty 
Propellers, 114 Powers Court, Sterling, VA 20166, phone: 703-421-
4434; fax: 703-450-0087.
    (m) You may review copies at the FAA, New England Region, 12 New 
England Executive Park, Burlington, MA; or at the National Archives 
and Records Administration (NARA). For information on the 
availability of this material at NARA, call 202-741-6030, or go to: 
http://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Burlington, Massachusetts, on September 7, 2011.
Peter A. White,
Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-25653 Filed 10-4-11; 8:45 am]
BILLING CODE 4910-13-P

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