[Federal Register Volume 70, Number 59 (Tuesday, March 29, 2005)]
[Proposed Rules]
[Pages 15784-15786]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-6108]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-20742; Directorate Identifier 2005-NE-03-AD]
RIN 2120-AA64


Airworthiness Directives; Rolls-Royce Corporation (Formerly 
Allison Engine Company) 501-D22A, 501-D22C, and 501-D22G Turboprop 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for Rolls-Royce Corporation (RRC) (formerly Allison Engine Company) 
501-D22A, 501-D22C, and 501-D22G turboprop engines. This proposed AD 
would require a onetime inspection for proper metal hardness of certain 
1st stage, 2nd stage, 3rd stage, and 4th stage turbine wheels. This 
proposed AD results from a report of a turbine wheel found to be over 
dimensional limits, caused by improper metal hardness. We are proposing 
this AD to prevent uncontained turbine wheel failure, leading to damage 
of the airplane and total loss of engine power.

DATES: We must receive any comments on this proposed AD by May 31, 
2005.

ADDRESSES: Use one of the following addresses to comment on this 
proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590-0001.
     Fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    You can get the service information identified in this proposed AD 
from Rolls-Royce Corporation, P.O. Box 420, 2001 South Tibbs Avenue, 
Indianapolis, IN 46206-0420; telephone (317) 230-2000; fax (317) 230-
4020.
    You may examine the comments on this proposed AD in the AD docket 
on the Internet at http://dms.dot.gov.

FOR FURTHER INFORMATION CONTACT: Michael Downs, Aerospace Engineer, 
Chicago Aircraft Certification Office, FAA, 2300 East Devon Avenue, Des 
Plaines, IL 60018; telephone (847) 294-7870; fax (847) 294-7834.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send us any written relevant data, views, or 
arguments regarding this proposal. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2005-20742; 
Directorate Identifier 2005-NE-03-AD'' in the subject line of your 
comments. We specifically invite comments on the overall regulatory,

[[Page 15785]]

economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of the 
DMS Web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You may review the DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78) or you 
may visit http://dms.dot.gov.

Examining the AD Docket

    You may examine the docket that contains the proposal, any comments 
received and, any final disposition in person at the DMS Docket Offices 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Office (telephone (800) 647-5227) is located on 
the plaza level of the Department of Transportation Nassif Building at 
the street address stated in ADDRESSES. Comments will be available in 
the AD docket shortly after the DMS receives them.

Discussion

    During the rebuild of an RRC 501 industrial engine's 1st stage 
turbine wheel that had accumulated 31,000 hours time-in-service, the 
assembled turbine blade lengths were found to be varying up to 0.012-
inch beyond the blade tip run-out limit. The shop inspector considered 
the turbine wheel suspect and returned it to RRC for metallurgical 
evaluation. That evaluation revealed that a portion of the turbine 
wheel had an increased radius, over the maximum radius limit, and a 
metal hardness below design requirements. RRC reviewed the forging 
furnace records at the forging plant that heat-treated the turbine 
wheel. The records showed that the temperature of the heat-treatment 
solution was about 100 degrees Fahrenheit below the minimum required 
temperature, for about two hours during the heat-treatment process. RRC 
reports that the effects of the improper heat treatment are a reduction 
in metal strength, lower tensile yield, and probability of metal creep, 
stress rupture, and metal fatigue. The same forging plant heat-treated 
RRC 501-D22A, 501-D22C, and 501-D22G turboprop engine 1st stage, 2nd 
stage, 3rd stage, and 4th stage turbine wheels. Those turbine wheels 
are suspect for improper metal hardness. This condition, if not 
corrected, could result in uncontained turbine wheel failure, leading 
to airplane damage and total loss of engine power.

Relevant Service Information

    We have reviewed and approved the technical contents of Rolls-Royce 
Commercial Engine Bulletins (CEBs) No. CEB-72-1138, No. CEB-72-4051, 
and No. CEB-72-1584, (combined in one document) dated January 23, 2004. 
These bulletins describe procedures for performing a onetime inspection 
for proper metal hardness of certain 1st stage, 2nd stage, 3rd stage, 
and 4th stage turbine wheels.

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 
a onetime inspection for proper metal hardness of certain 1st stage, 
2nd stage, 3rd stage, and 4th stage turbine wheels. These inspections 
would be done at the next shop visit of the engine or turbine module, 
but not to exceed 7,400 cycles-since-new of any 1st stage, 2nd stage, 
3rd stage, or 4th stage turbine wheel. The proposed AD would require 
you to use the service information described previously to perform 
these actions.

Costs of Compliance

    There are about 150 RRC 501-D22A, 501-D22C, and 501-D22G turboprop 
engines of the affected design in the worldwide fleet. We estimate that 
150 engines installed on airplanes of U.S. registry would be affected 
by this proposed AD. We also estimate that it would take about 0.5 work 
hour per engine to perform the proposed actions, and that the average 
labor rate is $65 per work hour. Required parts would cost about $1,495 
per turbine wheel. The manufacturer has stated that it may provide 
replacement parts for turbine wheels that do not meet inspection 
criteria, at no cost to operators. Based on these figures, we estimate 
the total cost of the proposed AD to U.S. operators to be $229,125.

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); 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 at the 
address listed under ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    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.

[[Page 15786]]

Sec.  39.13  [Amended]

    2. The FAA amends Sec.  39.13 by adding the following new 
airworthiness directive:

Rolls-Royce Corporation (formerly Allison Engine Company): Docket 
No. FAA-2005-20742; Directorate Identifier 2005-NE-03-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by May 31, 
2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Rolls-Royce Corporation (RRC) (formerly 
Allison Engine Company) 501-D22A, 501-D22C, and 501-D22G turboprop 
engines with the turbine wheels listed in the following Table 1, 
installed.

                                        Table 1.--Affected Turbine Wheels
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           Turbine wheel part No.                           Turbine wheel                       Serial Nos.
----------------------------------------------------------------------------------------------------------------
6875431....................................  1st Stage..................................  KK50152 through
                                                                                           KK50199.
6845592....................................  2nd Stage..................................  KK40998 through
                                                                                           KK41057.
6845593....................................  3rd Stage..................................  KK36452 through
                                                                                           KK36461, and KK36492
                                                                                           through KK36532.
6870434....................................  4th Stage..................................  KK40320 through
                                                                                           KK40393, and KK40485
                                                                                           through KK40535.
----------------------------------------------------------------------------------------------------------------

    These engines are installed on, but not limited to, Commercial 
Hercules L-100-20, L-100-30, L-382B, L-382E, and L-382G, Airbus 
Super Guppy-201, and Super Convair CV-580A, and CV5800 airplanes.

Unsafe Condition

    (d) This AD results from a report of a turbine wheel found to be 
over dimensional limits, caused by improper metal hardness. We are 
issuing this AD to prevent uncontained turbine wheel failure, 
leading to damage of the airplane and total loss of engine power.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed at the next shop visit of the engine or turbine module, 
but not to exceed 7,400 cycles-since-new of any 1st stage, 2nd 
stage, 3rd stage, or 4th stage turbine wheel, unless the actions 
have already been done.

Onetime Inspection for Proper Metal Hardness

    (f) Perform a onetime inspection for proper metal hardness of 
1st stage, 2nd stage, 3rd stage, and 4th stage turbine wheels. Use 
paragraphs 2.B. and 2.F. of RRC Commercial Engine Bulletins (CEBs) 
No. CEB-72-1138, No. CEB-72-4051, and No. CEB-72-1584, (combined in 
one document) dated January 23, 2004.
    (g) Remove from service any turbine wheel that does not pass 
inspection, using paragraph 2.C. of RRC CEBs No. CEB-72-1138, No. 
CEB-72-4051, and No. CEB-72-1584, (combined in one document) dated 
January 23, 2004.
    (h) Mark the letters, HC, after the serial number on any turbine 
wheel that passes inspection, using the method described in 
paragraph 2.D. of RRC CEBs No. CEB-72-1138, No. CEB-72-4051, and No. 
CEB-72-1584, (combined in one document) dated January 23, 2004.

Reporting Requirements

    (i) Report findings of inspections using the procedures 
specified in paragraph 2.E. of RRC CEBs No. CEB-72-1138, No. CEB-72-
4051, and No. CEB-72-1584, (combined in one document) dated January 
23, 2004. The Office of Management and Budget (OMB) has approved the 
reporting requirements specified in paragraph 2.E. of RRC CEBs No. 
CEB-72-1138, No. CEB-72-4051, and No. CEB-72-1584, (combined in one 
document) dated January 23, 2004, and assigned OMB control number 
2120-0056.

Definition

    (j) For the purpose of this AD, a serviceable turbine wheel is:
    (1) A turbine wheel that has a serial number not listed in this 
AD; and
    (2) A turbine wheel that has a serial number listed in this AD 
that passed the inspection specified in paragraph (f) of this AD.

Alternative Methods of Compliance

    (k) 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

    (1) None.

    Issued in Burlington, Massachusetts, on March 22, 2005.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 05-6108 Filed 3-28-05; 8:45 am]
BILLING CODE 4910-13-P