Airworthiness Directives; Dowty Propellers Constant Speed Propellers

[Federal Register Volume 79, Number 231 (Tuesday, December 2, 2014)]
[Rules and Regulations]
[Pages 71300-71302]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-28325]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-0776; Directorate Identifier 2009-NE-32-AD; 
Amendment 39-18007; AD 2010-17-11R2]
RIN 2120-AA64


Airworthiness Directives; Dowty Propellers Constant Speed 
Propellers

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are revising airworthiness directive (AD) 2010-17-11R1, 
which applies to all Dowty Propellers R408/6-123-F/17 model propellers. 
AD 2010-17-11R1 required initial application of sealant between the bus 
bar assembly and the backplate assembly of certain line-replaceable 
units (LRUs) and repetitive re-applications of sealant on all R408/6-
123-F/17 model propellers. AD 2010-17-11R1 also provided an optional 
terminating action to the repetitive re-application of sealant. This AD 
increases the interval allowed between the required re-application of 
sealant, and specifies an additional acceptable sealant. This AD was 
prompted by failure of the propeller de-ice bus bar due to friction or 
contact between the bus bar and the backplate assembly, consequent 
intermittent short circuit, and possible double generator failure. We 
are issuing this AD to prevent an in-flight double generator failure, 
which could result in reduced control of the airplane.

DATES: This AD is effective January 6, 2015.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of January 6, 
2015.

ADDRESSES: For service information identified in this AD, contact Dowty 
Propellers, Anson Business Park, Cheltenham Road East, Gloucester GL2 
9QN, UK; phone: 44 0 1452 716000; fax: 44 0 1452 716001. You may view 
this 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 by searching for and locating Docket No. FAA-2009-
0776; 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 AD, the mandatory continuing airworthiness information, 
regulatory evaluation, any comments received, and other information. 
The address for the Docket Office (phone: 800-647-5527) is Document 
Management Facility, U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.

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; email: [email protected].

SUPPLEMENTARY INFORMATION: 

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to revise AD 2010-17-11R1, Amendment 39-17481 (78 FR 41283, 
July 10, 2013), (``AD 2010-17-11R1''). AD 2010-17-11R1 applied to the 
specified products. The NPRM published in the Federal Register on March 
19, 2014 (79 FR 15269). The NPRM proposed to require increasing the 
interval allowed between the required re-application of sealant and 
specified an additional acceptable sealant.

Comments

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

Request Correction to the Applicability and Compliance Paragraphs

    Horizon Air requested a correction in the Applicability and 
Compliance paragraphs for possible typographical errors between AD 
2010-17-11R1 and the NPRM (79 FR 15269, March 19, 2014). Horizon Air 
stated that the Applicability has changed from ``. . . serial number 
(S/N) below DAP0327'' in AD 2010-17-11R1 to ``. . . S/N below DAP0927'' 
in the proposed rule. With no discussion about the increased number of 
affected propellers, Horizon Air believes that typographical errors 
exist in the Applicability and Compliance sections.
    We do not agree. AD 2010-17-11R1 required initial sealant 
application to all Dowty Propellers R408/6-123-F/17 model propellers 
with a hub, actuator, and backplate assembly LRU S/Ns below DAP0347, 
not DAP0327 as quoted above. AD 2010-17-11R1 also required repetitive 
re-application of sealant for all LRU S/Ns below DAP0927. We did not 
change this AD.

Request Change to Optional Terminating Action

    Horizon Air requested that all revisions to Dowty Propellers 
Service Bulletin (SB) No. D8400-61-94 be included in the Optional 
Terminating Action paragraph. The implied reason for this request was 
to support terminating action throughout the range of qualified SBs.
    We partially agree. We agree that Dowty Propellers SB No. D8400-61-
94, Revision 6, dated December 12, 2013 and earlier revisions provide 
adequate corrective actions to address the unsafe condition. We changed 
the Optional Terminating Action paragraph to include Dowty Propellers 
SB No. D8400-61-94, Revision 6, dated December 12, 2013 and earlier 
revisions.
    We do not agree that unknown future SB versions should be included 
in this AD. The content of future SB revisions is speculation. We did 
not change this AD to include all revisions of the SB.

Request for Alternative Method of Compliance

    Horizon Air requested that we allow the use of 3M 4200 sealant as 
an equivalent replacement for the 3M 5300 sealant.
    We agree. We approved 3M 4200 as an acceptable sealant in response 
to the Horizon Air comment to AD 2010-17-11R1 when that AD was at the 
NPRM stage; see 78 FR 41283, July 10, 2013. 3M 4200 sealant is also one 
of three sealants identified in Dowty Propellers Alert Service Bulletin 
(ASB) No. D8400-

[[Page 71301]]

61-A66, Revision 8, dated October 31, 2013. That Dowty ASB is 
incorporated by reference to this AD and is authorized for use when 
performing paragraph (g) of this AD. We did not change this AD.

Conclusion

    We reviewed the available data, including the comments received, 
and determined that air safety and the public interest require adopting 
this 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 this AD.

Costs of Compliance

    We estimate that this AD affects 104 propellers installed on 
airplanes of U.S. registry. We also estimate that it will take about 2 
hours per propeller to comply with this AD. The average labor rate is 
$85 per hour. Required parts cost about $20 per propeller. Based on 
these figures, we estimate the cost of this AD on U.S. operators to be 
$19,760.

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

    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 that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979),
    (3) Will not affect intrastate aviation in Alaska to the extent 
that it justifies making a regulatory distinction, 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.

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 part 39 of the Federal Aviation 
Regulations (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 removing airworthiness directive (AD) 
2010-17-11R1, Amendment 39-17481 (78 FR 41283, July 10, 2013), and 
adding the following new AD:

2010-17-11R2 Dowty Propellers Constant Speed Propellers: Amendment 
39-18007; Docket No. FAA-2009-0776; Directorate Identifier 2009-NE-
32-AD.

(a) Effective Date

    This AD is effective January 6, 2015.

(b) Affected ADs

    This AD revises AD 2010-17-11R1, Amendment 39-17481 (78 FR 
41283, July 10, 2013).

(c) Applicability

    This AD applies to Dowty Propellers R408/6-123-F/17 model 
propellers with a hub, actuator, and backplate assembly line-
replaceable unit (LRU) serial number (S/N) below DAP0927.

(d) Unsafe Condition

    This AD was prompted by failure of the propeller de-ice bus bar 
due to friction or contact between the bus bar and the backplate 
assembly, consequent intermittent short circuit, and possible double 
generator failure. We are issuing this AD to prevent an in-flight 
double generator failure, which could result in reduced control of 
the airplane.

(e) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.
    (1) For R408/6-123-F/17 model propellers with a hub, actuator, 
and backplate assembly LRU S/N below DAP0347, do the following 
initial sealant application within 5,000 flight-hours (FHs) after 
September 27, 2010, or within 100 FHs after the effective date of 
this AD, whichever occurs later:
    (i) Apply a sealant specified in Dowty Propellers Alert Service 
Bulletin (ASB) No. D8400-61-A66, Revision 8, dated October 31, 2013 
between the bus bar assemblies and the backplate assembly.
    (ii) Use paragraph 3.A. or 3.B. of the Accomplishment 
Instructions of Dowty Propellers ASB No. D8400-61-A66, Revision 8, 
dated October 31, 2013, to apply the sealant.
    (2) Thereafter, for R408/6-123-F/17 model propellers, with a 
hub, actuator, and backplate assembly LRU S/N below DAP0927, re-
apply sealant as specified in paragraphs (e)(1)(i) and (e)(1)(ii) of 
this AD within every additional 10,500 FHs.

(f) Installation Prohibition

    After the effective date of this AD, do not install any Dowty 
Propellers R408/6-123-F/17 model propeller unless 3M 5300 or 3M 4200 
sealant was applied between the bus bar assembly and the backplate 
assembly as required by this AD, or unless the optional terminating 
action as specified in paragraph (g) of this AD was performed.

(g) Optional Terminating Action

    As optional terminating action to the sealant application 
required by paragraph (e) of this AD, replace the bus bar assembly 
with a slip ring de-icer harness. Use paragraph 3.A. of the 
Accomplishment Instructions of Dowty Propellers Service Bulletin 
(SB) No. D8400-61-94, Revision 6, dated December 12, 2013, to do the 
replacement.

(h) Credit for Previous Actions

    (1) Sealant applications performed before the effective date of 
this AD using Dowty Propellers SB No. D8400-61-66, dated February 9, 
2007; Revision 1, dated May 4, 2007; ASB No. D8400-61-A66, Revision 
2, dated August 19, 2009; Revision 3, dated November 10, 2009; 
Revision 4, dated January 19, 2010; Revision 5, dated June 16, 2010; 
Revision 6, dated August 17, 2011; or Revision 7, dated December 1, 
2011, satisfy the initial sealant application required by paragraph 
(e) of this AD.
    (2) Replacement of the busbar assembly with a slip ring de-icer 
harness before the effective date of this AD using Dowty Propellers 
SB No. D8400-61-94, Revision 2, dated August 29, 2012; Revision 3, 
dated October 23, 2012; Revision 4, dated June 12, 2013; or Revision 
5, dated September 2, 2013, satisfies the optional terminating 
action specified in paragraph (g) of this AD.

(i) Alternative Methods of Compliance (AMOCs)

    The Manager, Boston Aircraft Certification Office, may approve 
AMOCs for this AD. Use the procedures found in 14 CFR 39.19 to make 
your request.

(j) Related Information

    (1) For more information about this AD, contact Michael Schwetz, 
Aerospace

[[Page 71302]]

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; email: 
[email protected].
    (2) Refer to MCAI European Aviation Safety Agency AD 2009-
0114R2, (Correction: December 16, 2013), dated December 13, 2013, 
for more information. You may examine the MCAI in the AD docket on 
the Internet at http://www.regulations.gov/#!documentDetail;D=FAA-
2009-0776-0014.
    (3) Dowty Propellers SB No. D8400-61-66, dated February 9, 2007; 
Revision 1, dated May 4, 2007; ASB No. D8400-61-A66, Revision 2, 
dated August 19, 2009; Revision 3, dated November 10, 2009; Revision 
4, dated January 19, 2010; Revision 5, dated June 16, 2010; Revision 
6, dated August 17, 2011; or Revision 7, dated December 1, 2011, 
which are not incorporated by reference in this AD, can be obtained 
from Dowty Propellers, using the contact information in paragraph 
(k)(3) of this AD.
    (4) Dowty Propellers SB No. D8400-61-94, Revision 2, dated 
August 29, 2012; Revision 3, dated October 23, 2012; Revision 4, 
dated June 12, 2013; or Revision 5, dated September 2, 2013, which 
are not incorporated by reference in this AD, can be obtained from 
Dowty Propellers, using the contact information in paragraph (k)(3) 
of this AD.
    (5) You may view this 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.

(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Dowty Propellers Alert Service Bulletin No. D8400-61-A66, 
Revision 8, dated October 31, 2013.
    (ii) Dowty Propellers Service Bulletin No. D8400-61-94, Revision 
6, dated December 12, 2013.
    (3) For Dowty Propellers service information identified in this 
AD, contact Dowty Propellers, Anson Business Park, Cheltenham Road 
East, Gloucester GL2 9QN, UK; phone: 44-0-1452-716000; fax: 44-0-
1452-716001.
    (4) You may view this service information at 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.
    (5) You may view this service information 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 November 3, 2014.
Kim Smith,
Acting Directorate Manager, Engine & Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2014-28325 Filed 12-1-14; 8:45 am]
BILLING CODE 4910-13-P

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