AD 2011-19-02
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Dowty Propellers | (c) R212/4-30-4/ | Airworthiness Directives; Dowty Propellers Type R212/4-30-4/22 and R251/4-30-4/49 Propeller Assemblies |
| aircraft | Dowty Propellers | (c) R251/4-30-4/ | Airworthiness Directives; Dowty Propellers Type R212/4-30-4/22 and R251/4-30-4/49 Propeller Assemblies |
| propeller | Dowty Propellers | (c) R212/4-30-4/ | Airworthiness Directives; Dowty Propellers Type R212/4-30-4/22 and R251/4-30-4/49 Propeller Assemblies |
| propeller | Dowty Propellers | (c) R251/4-30-4/ | Airworthiness Directives; Dowty Propellers Type R212/4-30-4/22 and R251/4-30-4/49 Propeller Assemblies |
Unsafe Condition
Reports of cracks in the propeller hub port buttress threads of R212 and R251 propellers, affecting hubs with over 6,000 flight hours. This could lead to propeller blade separation, potentially causing damage to the airplane and/or injury to persons on the ground.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect the buttress threads in the propeller hub and driving center assembly for cracks within 500 flight hours after the effective date, and repeat inspections at intervals not exceeding 500 flight hours. Use Dowty Propellers Alert Service Bulletin No. 61-1043, Revision 7, and NDT Technique NDT 175U for the inspection. Remove the propeller assembly from service if a crack is found. Do not install the propeller unless the hub and driving center have passed the required inspections.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 500 flight hours after the effective date
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Dowty Propellers Type R212/4-30-4/22 propeller assemblies with hub and driving center assembly part numbers 601022105, 601022211, 601022294, 601021426, 601021858, or 601021859, and Type R251/4-30-4/49 propeller assemblies with hub and driving center assembly part numbers 660207202 or 660207203.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
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:
Document Text
Show stored source text (verify against official source)
[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 [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[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:
<a href="/cdn-cgi/l/email-protection#b2dfdbd1dad3d7de9cc1d1dac5d7c6c8f2d4d3d39cd5ddc4"><span class="__cf_email__" data-cfemail="14797d777c7571783a67777c6371606e547275753a737b62">[email protected]</span></a>.
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 <a href="http://www.regulations.gov">http://www.regulations.gov</a>; 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: <a href="/cdn-cgi/l/email-protection#076a6e646f66626b2974646f7062737d4761666629606871"><span class="__cf_email__" data-cfemail="74191d171c1511185a07171c0311000e341215155a131b02">[email protected]</span></a> 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:
<a href="http://www.archives.gov/federal-register/cfr/ibr-locations.html">http://www.archives.gov/federal-register/cfr/ibr-locations.html</a>.
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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Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
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