Document ID: FAA-2009-0776-0012
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Dowty Propellers Constant Speed Propellers
Posted Date: 2014-03-19T04:00Z

[Federal Register Volume 79, Number 53 (Wednesday, March 19, 2014)]
[Proposed Rules]
[Pages 15269-15271]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-06010]

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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]
RIN 2120-AA64

Airworthiness Directives; Dowty Propellers Constant Speed 
Propellers

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to revise airworthiness directive (AD) 2010-17-
11R1, which applies to all Dowty Propellers R408/6-123-F/17 model 
propellers. AD 2010-17-11R1 requires initial and repetitive application 
of sealant between the bus bar assembly and the backplate assembly of 
certain line-replaceable units (LRUs). That AD also provides an 
optional terminating action to the repetitive re-application of 
sealant. This proposed AD would increase the interval allowed between 
the required re-application of sealant, and would specify an additional 
acceptable sealant. We are proposing this AD to prevent an in-flight 
double generator failure, which could result in reduced control of the 
airplane.

DATES: We must receive comments on this proposed AD by May 19, 2014.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    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 proposed AD, the mandatory continuing airworthiness 
information, the regulatory evaluation, any comments received, and 
other information. The street address for the Docket Office (phone: 
800-647-5527) is in the ADDRESSES section. Comments will be available 
in the AD docket shortly after receipt.

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: michael.schwetz@faa.gov.

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-2009-0776; 
Directorate Identifier 2009-NE-32-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 because of those comments.
    We will post all comments we receive, without change, to http://

[[Page 15270]]

www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    On August 5, 2010, we issued AD 2010-17-11, Amendment 39-16403 (75 
FR 51656, August 23, 2010), (``AD 2010-17-11''), for Dowty Propellers 
model R408/6-123-F/17 propellers. AD 2010-17-11 required initial 
application and repetitive re-application of sealant between the bus 
bar assembly and the backplate assembly of LRU serial numbers below 
DAP0347. AD 2010-17-11 resulted from 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 
dual alternating current generator failure.
    On June 18, 2013, we issued AD 2010-17-11R1, Amendment 39-17481 (78 
FR 41283, July 10, 2013), for Dowty Propellers R408/6-123-F/17 model 
propellers. AD 2010-17-11R1 added an optional terminating action to the 
requirement for the repetitive re-application of sealant. AD 2010-17-
11R1 resulted from Dowty Propellers development of a new slip ring de-
icer harness to replace the bus bar assembly. We issued AD 2010-17-11R1 
to prevent an in-flight double generator failure, which could result in 
reduced control of the airplane.

Actions Since AD 2010-17-11R1 Was Issued

    Since we issued AD 2010-17-11R1, Dowty Propellers issued Alert 
Service Bulletin (ASB) No. D8400-61-A66, Revision 8, dated October 31, 
2013. That ASB increased the interval between required re-application 
of sealant from 10,000 flight hours (FHs) to 10,500 FHs. That ASB 
identified an additional acceptable sealant. The European Aviation 
Safety Agency has issued AD 2009-0114R2, dated December 16, 2013, which 
incorporates the revised schedule for re-application of sealant.

Relevant Service Information

    We reviewed Dowty Propellers ASB No. D8400-61-A66, Revision 8, 
dated October 31, 2013. The ASB describes procedures for performing 
initial and repetitive re-application of sealant between the bus bar 
assembly and the backplate assembly of certain LRUs.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design.

Proposed AD Requirements

    This proposed AD would increase the interval from 10,000 FHs to 
10,500 FHs between re-application of sealant, and would allow use of an 
additional acceptable sealant.

Costs of Compliance

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

    We have 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 that the 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),
    (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.

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

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. Amend 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:

Dowty Propellers: Docket No. FAA-2009-0776; Directorate Identifier 
2009-NE-32-AD.

(a) Comments Due Date

    The FAA must receive comments on this AD action by May 19, 2014.

(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

[[Page 15271]]

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 a sealant 
specified in Dowty Propellers ASB No. D8400-61-A66, Revision 8, 
dated October 31, 2013 was applied between the bus bar assembly and 
the backplate assembly as specified 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 
requirements 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 2, dated August 29, 2012, or Revision 3, dated October 
23, 2012, to do the replacement.

(h) Credit for Previous Actions

    Sealant applications performed before the effective date of this 
AD using Dowty Propellers SB No. D8400-61-66, dated February 9, 
2007; or Revision 1, dated May 4, 2007; or ASB No. D8400-61-A66, 
Revision 2, dated August 19, 2009; or Revision 3, dated November 10, 
2009; or Revision 4, dated January 19, 2010; or Revision 5, dated 
June 16, 2010; or Revision 6, dated August 17, 2011; or Revision 7, 
dated December 1, 2011, satisfy the initial sealant application 
requirement 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 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: 
michael.schwetz@faa.gov.
    (2) Refer to MCAI European Aviation Safety Agency, AD 2009-
0114R2, dated December 16, 2013, for more information. You may 
examine the MCAI in the AD docket on the Internet at http://www.regulations.gov by searching for and locating it in Docket No. 
FAA-2009-0776.
    (3) Dowty Propellers ASB No. D8400-61-A66, Revision 8, dated 
October 31, 2013, and Dowty Propellers SB No. D8400-61-94, Revision 
3, dated October 23, 2012, pertain to the subject of this AD and can 
be obtained from Dowty Propellers, using the contact information in 
paragraph (j)(4) of this AD.
    (4) 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.
    (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.

    Issued in Burlington, Massachusetts, on March 11, 2014.
Kim Smith,
Acting Directorate Manager, Engine & Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2014-06010 Filed 3-18-14; 8:45 am]
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