
[Federal Register Volume 78, Number 26 (Thursday, February 7, 2013)]
[Proposed Rules]
[Pages 9005-9007]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-02730]


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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 Propellers

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to revise an existing airworthiness directive (AD) 
that applies to all Dowty Propellers R408/6-123-F/17 model propellers. 
The existing AD currently requires initial applications of sealant 
between the bus bar assembly and the backplate assembly of certain 
line-replaceable units (LRUs), and repetitive applications of sealant 
on all R408/6-123-F/17 model propellers. Since we issued that AD, Dowty 
Propellers has introduced an optional terminating action to the 
applications of sealant. This proposed AD would add the optional 
terminating action. We are proposing this AD to prevent an in-flight 
double generator failure, which could result in reduced controllability 
of the airplane.

DATES: We must receive comments on this proposed AD by April 8, 2013.

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 GL 
29QN, 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; 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 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 and Propeller 
Directorate, 12 New England Executive Park, Burlington, MA 01803; 
phone: 781-238-7761; fax 781-238-7170; e- mail: 
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://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), for all Dowty Propellers R408/6-123-F/17 
model propellers. That AD requires initial applications of sealant 
between the bus bar assembly and the backplate assembly of LRUs serial 
numbers below DAP0347, and repetitive applications of sealant on all 
R408/6-123-F/17 model propellers. That AD resulted from mandatory 
continuing airworthiness information issued by an aviation authority of 
another country to identify and correct an unsafe condition on an 
aviation product. We issued that AD to prevent an in-flight double 
generator

[[Page 9006]]

failure, which could result in reduced controllability of the airplane.

Actions Since Existing AD Was Issued

    Since we issued AD 2010-17-11 (75 FR 51656, August 23, 2010), Dowty 
Propellers introduced an optional terminating action to the repetitive 
applications of sealant. That action consists of replacing the bus bar 
assembly with a slip ring de-icer harness.

Relevant Service Information

    We reviewed Dowty Propellers Service Bulletin (SB) No. D8400-61-94, 
Revision 3, dated October 23, 2012. The SB describes procedures for 
replacing the bus bar assembly with a slip ring de-icer harness.

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 retain all the requirements of AD 2010-17-11 
(75 FR 51656, August 23, 2010). This proposed AD would add an optional 
terminating action to the applications of sealant by replacing the bus 
bar assembly with a slip ring de-icer harness.

Costs of Compliance

    We estimate that this proposed AD would affect about 104 propellers 
installed on airplanes of U.S. registry. We also estimate that it would 
take about 2 hours per propeller to apply sealant and required sealant 
would cost about $20 per propeller. We also estimate that it would take 
about 3 hours to replace the bus bar with a de-icer slip ring harness 
and required parts would cost about $1,200 per propeller. The average 
labor rate is $85 per hour. Based on these figures, we estimate the 
cost of the proposed AD on U.S. operators to be $171,080. Our cost 
estimate is exclusive of possible warranty coverage.

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. The FAA amends Sec.  39.13 by removing airworthiness directive (AD) 
2010-17-11, Amendment 39-16403 (75 FR 51656, August 23, 2010), and 
adding the following new AD:

Dowty Propellers (formerly Dowty Aerospace; Dowty Rotol Limited; and 
Dowty Rotol): Docket No. FAA-2009-0776; Directorate Identifier 2009-
NE-32-AD.

(a) Comments Due Date

    We must receive comments on this AD action by April 8, 2013.

(b) Affected ADs

    This AD revises AD 2010-17-11, Amendment 39-16403 (75 FR 51656, 
August 23, 2010).

(c) Applicability

    (1) This AD applies to Dowty Propellers R408/6-123-F/17 model 
propellers. These propellers are installed on, but not limited to, 
Bombardier, Inc. (formerly de Havilland Canada) models DHC-8-400, 
DHC-8-401, and DHC-8-402 series airplanes.

(d) Unsafe Condition

    This AD was prompted by the need to add an optional terminating 
action to the applications of sealant. We are issuing this AD to 
prevent an in-flight double generator failure, which could result in 
reduced controllability 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 line-replaceable unit serial numbers below 
DAP0347, do the following initial sealant application within 5,000 
flight hours (FH) after September 27, 2010, or within 100 FH from 
the effective date of this AD, whichever occurs later:
    (i) Apply sealant between the bus bar assemblies and the 
backplate assembly.
    (ii) Use paragraph 3 of the Accomplishment Instructions of Dowty 
Propellers Alert Service Bulletin No. D8400-61-A66, Revision 5, 
dated June 16, 2010, to apply the the sealant.
    (2) Thereafter, re-apply sealant as specified in paragraphs 
(e)(1)(i) through (e)(1)(ii) of this AD within every additional 
10,000 FH.

(f) Installation Prohibition

    After the effective date of this AD, do not install any Dowty 
Propellers R408/6-123-F/17 propeller unless sealant has been 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 (i) of this AD, has been performed.

(g) Differences Between This AD and the Service Information

    None.

(h) Credit for Actions Accomplished in Accordance With Previous Service 
Information

    (1) Sealant applications performed before the effective date of 
this AD using Dowty Propellers Service Bulletin No. D8400-61-66, 
dated February 9, 2007, Revision 1, dated May 4, 2007, Alert Service 
Bulletin No. D8400-61-A66, Revision 2, dated August 19, 2009, 
Revision 3, dated November 10, 2009, Revision 4, dated January 19, 
2010, or Revision 5, dated June 16, 2010, satisfy the

[[Page 9007]]

initial sealant application requirement of this AD.
    (2) Re-application of sealant within 10,000 FH since last 
application satisifies the reapplication requirement. However, 
unless you have incorporated the optional terminating action 
provided in this AD Revision, you must reapply the sealant per 
paragraph (e)(1)(i) of this AD.
    (3) Replacement of the bus bar assembly with a slip ring de-icer 
harness before the effective date of this AD using paragraph 3.A. of 
the Accomplishment Instructions of Dowty Propellers Service Bulletin 
No. D8400-61-94, Revision 2, dated August 29, 2012, satisfies the 
optional terminating requirement of this AD.

(i) Optional Terminating Action

    As optional terminating action to the sealant applications 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 No. D8400-61-94, Revision 3, dated 
October 23, 2012, to do the replacement.

(j) Alternative Methods of Compliance (AMOCs)

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

(k) Related Information

    (1) Refer to European Aviation Safety Agency AD 2009-0114R1 
(correction: Dated December 13, 2012) for related information.
    (2) For more information about this AD, contact Michael Schwetz, 
Aerospace Engineer, Boston Aircraft Certification Office, FAA, 
Engine and Propeller Directorate, 12 New England Executive Park, 
Burlington, MA 01803; phone: 781-238-7761; fax 781-238-7170; email: 
michael.schwetz@faa.gov.
    (3) For service information identified in this AD, contact Dowty 
Propellers, Anson Business Park, Cheltenham Road East, Gloucester GL 
29QN, 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.


    Issued in Burlington, Massachusetts, on January 29, 2013.
Colleen M. D'Alessandro,
Assistant Manager, Engine & Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2013-02730 Filed 2-6-13; 8:45 am]
BILLING CODE 4910-13-P


