Airworthiness Directives; Rolls-Royce Corporation (Formerly Allison Engine Company, Allison Gas Turbine Division, and Detroit Diesel Allison) (RRC) 250-B and 250-C Series Turboshaft and Turboprop Engines

[Federal Register Volume 69, Number 230 (Wednesday, December 1, 2004)]
[Rules and Regulations]
[Pages 69807-69809]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-26424]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2004-NE-10-AD; Amendment 39-13885; AD 2004-24-09]
RIN 2120-AA64


Airworthiness Directives; Rolls-Royce Corporation (Formerly 
Allison Engine Company, Allison Gas Turbine Division, and Detroit 
Diesel Allison) (RRC) 250-B and 250-C Series Turboshaft and Turboprop 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain RRC 250-B and 250-C series turboshaft and turboprop engines. 
This AD requires a onetime inspection of the fuel nozzle screen for 
contamination, and if contamination is found, inspection and cleaning 
of the entire aircraft fuel system before further flight. This AD also 
requires replacing the fuel nozzle with a new design fuel nozzle, at 
the next fuel nozzle overhaul or by June 30, 2006, whichever occurs 
first. This AD results from 10 reports of engine power loss with 
accompanying collapse of the fuel nozzle screen, due to fuel 
contamination. We are issuing this AD to minimize the risk of sudden 
loss of engine power and uncommanded shutdown of the engine due to fuel 
contamination and collapse of the screen in the fuel nozzle.

DATES: This AD becomes effective January 5, 2005.

ADDRESSES: You can get the service information identified in this 
proposed 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, by appointment, at the FAA, New 
England Region, Office of the Regional Counsel, 12 New England 
Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT: John Tallarovic, Aerospace Engineer, 
Chicago Aircraft Certification Office, FAA, 2300 East Devon Avenue, Des 
Plaines, IL 60018-4696; telephone (847) 294-8180; fax (847) 294-7834.

SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part 39 
with a proposed airworthiness directive (AD). The proposed AD applies 
to certain RRC 250-B and 250-C series turboshaft and turboprop engines. 
We published the proposed AD in the Federal Register on May 7, 2004 (69 
FR 25501). That action proposed to require:
    <bullet> A onetime inspection of the fuel nozzle screen for 
contamination, within 150 operating hours after the effective date of 
the proposed AD; and
    <bullet> Inspection and cleaning of the entire aircraft fuel system 
before further flight, if contamination is found; and
    <bullet> Replacement of the fuel nozzle with a serviceable (new 
design) fuel nozzle, at the next fuel nozzle overhaul or by June 30, 
2006, whichever occurs first.

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.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments received.

Request To Add Sikorsky Model S-76A Helicopter to the Applicability

    One commenter asks us to add the Sikorsky Model S-76A helicopter to 
the Applicability. The commenter states that the S-76A helicopter uses 
RRC model 250-C30 and 250-C30S engines. We agree. Although this AD is 
applicable to the RRC model 250-C30 and 250-C30S engines, we list 
airframes that might use the engines as an aid to the operators. We 
added the Sikorsky model S-76A helicopters to the ``used on but not 
limited to'' sentence in paragraph (c) of the final rule.

Request To Expand the Discussion Section of the Preamble

    One commenter asks us to expand the background information in the

[[Page 69808]]

Discussion section regarding the recent history of fuel nozzle 
contamination on the RCC Model 250 engines. The commenter feels the 
change will include more details to the public regarding the actual 
issues leading to the collapsed screen events and the potential risk to 
their specific operations. While we agree more details in the notice of 
proposed rulemaking (NPRM) could have been helpful to the public, that 
section is not included in a final rule. We did not change the final 
rule to add more details about the events.

Request To Change the Unsafe Condition Statement

    The same commenter asks us to change the unsafe condition statement 
in the Summary section of the preamble and in paragraph (d) of the 
regulatory text from ``to prevent * * * engine'' to ``to minimize the 
risk of * * * engine.'' The commenter wants to clarify that installing 
this new fuel nozzle with the modified screen will provide additional 
resistance to collapse of the screen when the screen is subjected to 
contaminated conditions. However, the modification cannot prevent or 
eliminate the risk of power loss when operating on aircraft with 
contaminated fuel. We agree. We changed the last sentence in the 
Summary section of the preamble and the last sentence in paragraph (d) 
of the regulatory text in the final rule to ``to minimize the risk of * 
* * engine.''

Suggestions That the AD Is Not Needed

    Two commenters feel that we do not need to issue an AD to address 
the unsafe condition. One commenter suggests that RRC revise the 
applicable maintenance manuals to reduce the inspection interval for 
the fuel nozzle screens from the current 1,500 hour interval to a 500 
hour interval. The commenter feels that the aircraft involved in the 
incidents might not have had maintenance performed using the 
appropriate maintenance publication, were not fueled from a known good 
source, or did not maintain their fuel system filters that are upstream 
of the fuel nozzle. We do not agree. As we stated in the NPRM, there 
are 10 instances where the affected engines experienced a power loss 
from contaminated fuel and collapse of the fuel nozzle screen. We feel 
that the onetime inspection is necessary to find any engines in service 
that have a contaminated fuel nozzle screen and impending collapse. The 
RRC Operation and Maintenance manual requires scheduled inspections at 
300-hour intervals when the fuel system does not have an aircraft fuel 
filter. The manual requires scheduled inspections at 1,500-hour 
intervals when the fuel system has an aircraft fuel filter. If we find 
the inspection intervals in the RRC manual are too long, we might 
propose changing those intervals in the future. We did not change the 
final rule.
    Another commenter feels that we don't need to issue an AD if 
operators maintain a clean fuel system, have a clean fuel supply 
system, and have methods in place to make sure they only use clean 
fuel. We do not agree. If there were always a clean supply of fuel, 
filters, screens, and nozzles, contaminants would never block them. 
Unfortunately, even with long-standing warnings by engine manufacturers 
about using contaminated fuel, our recent Special Airworthiness 
Information Bulletin on the matter, and all of the effort that goes 
into ensuring a clean fuel supply, it is not possible to prevent 
contamination entirely. Tests show the new design fuel nozzle screens 
are more resistant to sudden collapse when contaminated. Fuel flow 
through the new fuel nozzle screen will decrease gradually as the 
screen becomes contaminated. The decreased fuel flow will give the 
pilot more time to notice the problem and take action. When 
contaminated, the old design of fuel nozzle screen could collapse 
without warning and cause an abrupt reduction in fuel flow. We did not 
change the final rule.

Request To Require Changing the Rotorcraft Flight Manuals

    One commenter asks us to require changing the flight manuals, for 
the rotorcraft that use the affected engines, to direct the pilot to 
land the rotorcraft immediately when the fuel system goes into bypass 
mode. The commenter states the flight manuals for some rotorcraft 
direct operators to land immediately after entering bypass mode. Other 
flight manuals allow continued flight and only require addressing the 
issue before the next flight. We do not agree. This AD only addresses 
engine design issues. This is not the appropriate vehicle to change the 
rotorcraft flight manuals. We forwarded the suggested changes to the 
responsible FAA rotorcraft certification offices.

Request To Lower the Total Costs of Compliance

    One commenter asks us to lower the total Cost of Compliance from 
about $12,650,000 to about $2,760,000. The commenter states that an 
operator can buy the new fuel nozzle screens for about $81 each, and 
install them for about an additional $276 each. We do not agree. The 
new fuel nozzle screen has additional mesh material to make it more 
resistant to collapse than the original screen. This design difference 
may cause a difference in how fuel flows through the screen and nozzle 
spray tip. The OEM has developed and uses a procedure to check the fuel 
nozzle for proper operation after installing, which is why the AD is 
structured as it is. At this time, the only approved method to comply 
with the AD is to replace the existing nozzle assembly with an assembly 
that does not have a part number listed in the AD. We based the costs 
we used in our analysis on the cost of a new fuel nozzle assembly and 
the cost of a fuel nozzle assembly reworked to the new configuration 
during overhaul of the nozzle assembly. If an operator develops a 
method of complying with the AD that is less expensive and maintains an 
equivalent level of safety using FAA-approved screens, the operator may 
send that method to us as a request for an alternative method of 
compliance under the procedures found in 14 CFR 39.19. We did not 
change the final rule.

Conclusion

    We have carefully reviewed the available data, including the 
comments received, and determined that air safety and the public 
interest require adopting the AD with the changes described previously. 
We have determined that these changes will neither increase the 
economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

    There are about 15,000 RRC 250-B and 250-C series turboshaft and 
turboprop engines of the affected design in the worldwide fleet. We 
estimate that 10,000 engines installed on aircraft of U.S. registry 
will be affected by this AD. We also estimate that it will take about 1 
work hour per engine to perform the actions, and that the average labor 
rate is $65 per work hour. In addition, operators can either replace 
the fuel nozzle with a new one at a cost of about $2,595 or have the 
existing nozzle overhauled at a cost of about $850. We estimate that 
about 80% of the fuel nozzles will be overhauled and 20% will be 
replaced with a new nozzle. Therefore, we estimate that the required 
parts would cost, on average, about $1,200 per engine. Based on these 
figures, we estimate the total cost of the AD to U.S. operators to be 
$12,650,000.

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

[[Page 69809]]

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 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); 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 summary of the costs to comply with this AD 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. 2004-NE-10-AD'' in your request.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the Federal Aviation Administration 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 airworthiness 
directive (AD):

2004-24-09 Rolls-Royce Corporation: Amendment 39-13885. Docket No. 
2004-NE-10-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective January 
5, 2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Rolls-Royce Corporation (formerly Allison 
Engine Company, Allison Gas Turbine Division, and Detroit Diesel 
Allison) (RRC) 250-B and 250-C series turboshaft and turboprop 
engines in the following Table 1:

                   Table 1.--250-B and 250-C Series Turboshaft and Turboprop Engines Affected
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-B15A              -B15E              -B15G              -B17               -B17B              -B17C
-B17D              -B17E              -B17F              -B17F/1            -B17F/2            -C18
-C18A              -C18B              -C18C              -C20               -C20B              -C20C
-C20F              -C20J              -C20R              -C20R/1            -C20R/2            -C20R/4
-C20S              -C20W              -C28               -C28B              -C28C              -C30
-C30G              -C30G/2            -C30M              -C30P              -C30R              -C30R/1
-C30R/3            -C30R/3M           -C30S              -C30U              -C40B              -C47B
-C47M
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    These engines are installed on, but not limited to, Agusta 
Models A109, A109A, A109AII, and A109C; Bell Helicopter Textron 
Models 47, 206A, 206B, 206L, 206L-1, 206L-3, 206L-4, 407, and 430; 
B-N Group Models BN-2T and BN-2T-4R; Enstrom Models TH28, 480; and 
480B; Eurocopter Canada Limited Model BO 105 LS A-3; Eurocopter 
France Models AS355E, AS355F, AS355I, and AS355F2; Eurocopter 
Deutschland Models BO-105A, BO-105C, BO-105S, and BO-105LS A-1; 
Hiller Aviation Model FH-1100; McDonnell Douglas 369D, 369E, 369F, 
369H, 369HE, 369HM, 369HS, 369FF, and 500N; Schweizer TH269D; SIAI 
Marchetti s.r.l. Models SF600 and SF600A; and Sikorsky S-76A 
helicopters and airplanes.

Unsafe Condition

    (d) This AD results from 10 reports of engine power loss with 
accompanying collapse of the screen in the fuel nozzle, due to fuel 
contamination. We are issuing this AD to minimize the risk of sudden 
loss of engine power and uncommanded shutdown of the engine due to 
fuel contamination and collapse of the screen in the fuel nozzle.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified unless the 
actions have already been done.
    (f) Perform a onetime inspection of the fuel nozzle screen for 
contamination, within 150 operating hours after the effective date 
of this AD.
    (g) Inspect and clean the entire aircraft fuel system before 
further flight if there is any contamination on the screen.
    (h) Remove from service fuel nozzles, part numbers (P/Ns) 
6890917, 6899001, and 6852020, and replace with a serviceable fuel 
nozzle, at the next fuel nozzle overhaul after the effective date of 
this AD, or by June 30, 2006, whichever occurs first.

Definition

    (i) For the purposes of this AD, a serviceable fuel nozzle is 
defined as a nozzle that has a P/N not specified in, or addressed 
by, this AD.

Alternative Methods of Compliance

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

Related Information

    (k) Information related to the subject of this AD can be found 
in Rolls-Royce Corporation Alert Commercial Engine Bulletin, with 
the identification numbers of CEB-A-313, CEB-A-1394, CEB-A-73-2075, 
CEB--A-73-3118, CEB-A-73-4056, CEB-A-73-5029, CEB-A-73-6041, TP CEB-
A-183, TP CEB-A-1336, and TP CEB-A-73-2032, dated September 4, 2003.

Material Incorporated by Reference

    (l) None.

    Issued in Burlington, Massachusetts, on November 22, 2004.
Francis A. Favara,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 04-26424 Filed 11-30-04; 8:45 am]
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