[Federal Register Volume 69, Number 111 (Wednesday, June 9, 2004)]
[Proposed Rules]
[Pages 32287-32288]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-13010]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NE-23-AD]
RIN 2120-AA64


Airworthiness Directives; Rolls-Royce Corporation (formerly 
Allison Engine Company, Allison Gas Turbine Division, and Detroit 
Diesel Allison) (RRC) Models 250-C30R/3, -C30R/3M, -C47B, and--C47M 
Turboshaft Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to supersede an existing airworthiness 
directive (AD) for RRC models 250-C30R/3, -C30R/3M, -C47B, and -C47M 
turboshaft engines. That AD currently requires initial and repetitive 
electrical signal inspections of the hydromechanical unit (HMU) Power 
Lever Angle (PLA) potentiometer. This proposed AD would continue to 
require those inspections and would add replacement of the existing HMU 
with a new design HMU as a mandatory terminating action to the 
repetitive inspection requirements. This proposed AD results from the 
manufacturer releasing a redesigned HMU that has a dual-element 
potentiometer. We are proposing this AD to prevent uncommanded and 
sudden changes in engine power.

DATES: We must receive any comments on this proposed AD by August 9, 
2004.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD:
     By mail: Federal Aviation Administration (FAA), New 
England Region, Office of the Regional Counsel, Attention: Rules Docket 
No. 2003-NE-23-AD, 12 New England Executive Park, Burlington, MA 01803-
5299.
     By fax: (781) 238-7055.
     By e-mail: [email protected].
    You may get the service information referenced in this AD from 
Rolls-Royce Corporation, P.O. Box 420, Indianapolis, IN 46206-0420; 
telephone (317) 230-6400; fax (317) 230-4243.
    You may examine the AD docket at the FAA, New England Region, 
Office of the Regional Counsel, 12 New England Executive Park, 
Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Khailaa Hosny, Aerospace Engineer, 
Chicago Aircraft Certification Office, FAA, 2300 East Devon Avenue, Des 
Plaines, IL 60018-4696; telephone (847) 294-7134; fax (847) 294-7834.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to submit any written relevant data, views, or 
arguments regarding this proposal. Send your comments to an address 
listed under ADDRESSES. Include ``AD Docket No. 2003-NE-23-AD'' in the 
subject line of your comments. If you want us to acknowledge receipt of 
your mailed comments, send us a self-addressed, stamped postcard with 
the docket number written on it; we will date-stamp your postcard and 
mail it back to you. We specifically invite comments on the overall 
regulatory, economic, environmental, and energy aspects of the proposed 
AD. If a person contacts us verbally, and that contact relates to a 
substantive part of this proposed AD, we will summarize the contact and 
place the summary in the docket. We will consider all comments received 
by the closing date and may amend the proposed AD in light of those 
comments.
    We are reviewing the writing style we currently use in regulatory 
documents. We are interested in your comments on whether the style of 
this document is clear, and your suggestions to improve the clarity of 
our communications that affect you. You may get more information about 
plain language at http://www.faa.gov/language and http://www.plainlanguage.gov.

Examining the AD Docket

    You may examine the AD Docket (including any comments and service 
information), by appointment, between 8 a.m. and 4:30 p.m., Monday 
through Friday, except Federal holidays. See ADDRESSES for the 
location.

Discussion

    On June 19, 2003, we issued AD 2003-13-10, Amendment 39-13210 (68 
FR 38590, June 30, 2003). That AD requires initial and repetitive 
inspections of the electrical signal from the HMU PLA potentiometer. 
That AD resulted from an investigation by the NTSB into uncommanded and 
sudden changes in engine power on a Bell 407 helicopter on March 27, 
2003. The NTSB investigation revealed that a potential undetected 
failure of the electrical signal from the PLA potentiometer, provided 
by the HMU of the full-authority digital-electronic control (FADEC) 
system, could cause uncommanded and sudden changes in engine power.

Actions Since AD 2003-13-10 Was Issued

    The manufacturer has released a new design HMU that incorporates a 
dual-element potentiometer. The dual-element function lessens the 
unsafe condition associated with the single-element design.

Relevant Service Information

    We have reviewed and approved the technical contents of RRC Service 
Bulletins (SBs) CEB A-73-3103, Revision 4, dated December 2, 2003, and 
CEB A-73-6030, Revision 4, dated December 2, 2003; that describe 
procedures for inspecting the PLA potentiometer signal.

Differences Between This Proposed AD and the Manufacturer's Service 
Information

    Although the combined RRC SB CEB A-73-3103 (250-C30 engines) and 
CEB A-73-6030 (250-C47 engines), Revision 4, dated December 2, 2003, 
also includes CEB A-73-5021 for 250-C40 engines, this AD is not 
applicable to the 250-C40 engine model because the 250-C40 engine model 
is used in twin-engine applications.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other products 
of this same type design. We are proposing this AD, which would 
require:

[[Page 32288]]

     An initial inspection of the electrical signal of the HMU 
PLA potentiometer within 300 flight hours (FH) after the effective date 
of this AD and;
     Repetitive inspections every 300 FH until the single-
element HMU is replaced with the dual-element HMU, and;
     Replacing the single-element HMU with a dual-element HMU 
within 600 FH after the effective date of the AD, or by January 30, 
2005, whichever occurs earlier.
    The proposed AD would require that you do these inspections using 
the service information described previously.

Costs of Compliance

    We estimate that 700 engines installed on helicopters of U.S. 
registry would be affected by this proposed AD. We estimate that it 
would take about 4 work hours per engine to replace a single-element 
HMU with a dual-element HMU. We also estimate that 15 percent of the 
single-element HMU's would fail the required inspection and require 
replacing the HMU. The average labor rate is $65 per work hour. 
Required parts would cost approximately $615 per engine. Based on these 
figures, we estimate the total cost of the proposed AD to U.S. 
operators to be $704,375.

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); and
    3. Would 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 summary of the costs to comply with this proposal and 
placed it in the AD Docket. You may get a copy of this summary by 
sending a request to us at the address listed under ADDRESSES. Include 
``AD Docket No. 2003-NE-23-AD'' in your request.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 14 
CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    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]

    2. The FAA amends Sec.  39.13 by removing Amendment 39-13210 (68 FR 
38590, June 30, 2003) and by adding a new airworthiness directive to 
read as follows:

Rolls-Royce Corporation (formerly Allison Engine Company, Allison 
Gas Turbine Division, and Detroit Diesel Allison): Docket No. 2003-
NE-23-AD. Supersedes AD 2003-13-10, Amendment 39-13210.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by August 9, 
2004.

Affected ADs

    (b) This AD Supersedes AD 2003-13-10.

Applicability

    (c) This AD is applicable to Rolls-Royce Corporation (formerly 
Allison Engine Company, Allison Gas Turbine Division, and Detroit 
Diesel Allison) (RRC) models 250-C30R/3, -C30R/3M, -C47B, and -C47M 
turboshaft engines that have a hydromechanical unit (HMU) with a 
part number (P/N) listed in 1.A. Group A of RRC Alert Commercial 
Engine Bulletin (ACEB) No. CEB A-72-3103, Revision 4, dated December 
2, 2003; and CEB A-72-6030, Revision 4, dated December 2, 2003. 
These engines are installed on, but not limited to, Bell OH-58D, 
Bell Helicopter Textron 407, Boeing AH/MH-6M, and MD Helicopters 
Inc. 600N helicopters.

Unsafe Condition

    (d) This AD results from the manufacturer releasing a redesigned 
HMU that has a dual-element potentiometer. We are issuing this AD to 
prevent uncommanded and sudden changes in engine power.

Compliance

    (e) Compliance with this AD is required as indicated, unless 
already done.

Initial Inspection

    (f) Perform an initial electrical signal inspection of the 
hydromechanical unit (HMU) PLA potentiometer, within 300 flight 
hours (FH) after the effective date of this AD. Use paragraphs 2.B. 
through 2.B.(8) and 2.B.(10) of the Accomplishment Instructions of 
RRC ACEB No. CEB A-73-3103, Revision 4, dated December 2, 2003; or 
CEB A-73-6030, Revision 4, dated December 2, 2003; to perform the 
inspection.
    (g) Replace the HMU before further flight if the electrical 
signal inspection result is unacceptable.

Repetitive Inspections

    (h) Thereafter, perform repetitive electrical signal inspections 
of the HMU PLA potentiometer within 300 FH of the last inspection. 
Use paragraphs 2.B. through 2.B.(8) and 2.B.(10) of the 
Accomplishment Instructions of RRC ACEB No. CEB A-73-3103, Revision 
4, dated December 2, 2003; or CEB A-73-6030, Revision 4, dated 
December 2, 2003; to perform the inspection.
    (i) Replace the HMU before further flight if the electrical 
signal inspection is unacceptable.

Mandatory Terminating Action

    (j) Replace the HMU with an HMU that has a P/N not specified in 
this AD within 600 FH after the effective date of this AD, or 
January 31, 2005, whichever occurs earlier. Replacing the HMU with 
an HMU that has a P/N not specified in this AD terminates the 
repetitive inspection requirement specified in paragraph (h) of this 
AD.

Alternative Methods of Compliance

    (k) The Manager, Chicago Aircraft Certification Office, FAA, has 
the authority to approve alternative methods of compliance for this 
AD if requested using the procedures found in 14 CFR 39.19.

Material Incorporated by Reference

    (l) None.

Related Information

    (m) None.

    Issued in Burlington, Massachusetts, on June 3, 2004.
Francis A. Favara,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 04-13010 Filed 6-8-04; 8:45 am]
BILLING CODE 4910-13-P