[Federal Register Volume 72, Number 170 (Tuesday, September 4, 2007)]
[Proposed Rules]
[Pages 50648-50650]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-17384]


 ========================================================================
 Proposed Rules
                                                 Federal Register
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
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  Federal Register / Vol. 72, No. 170 / Tuesday, September 4, 2007 / 
Proposed Rules  

[[Page 50648]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-27891; Directorate Identifier 2007-NE-14-AD]
RIN 2120-AA64


Airworthiness Directives; Honeywell International Inc. TFE731-2C, 
-3B, -3BR, -3C, -3CR, -3D, -3DR, -4R, -5AR, -5BR, -5R, -20R, -20AR, -
20BR, -40, -40AR, -40R, and -60 Series Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for Honeywell International Inc. (Honeywell) TFE731-2C, -3B, -3BR, -3C, 
-3CR, -3D, -3DR, -4R, -5AR, -5BR, -5R, -20R, -20AR, -20BR, -40, -40AR, 
-40R, and -60 series turbofan engines. This proposed AD would require 
removal from service of certain high pressure (HP) turbine rotor 
assemblies with part numbers (P/Ns) 3075772-1 and 3060841-1 using a 
drawdown schedule, and returning them to Honeywell for curvic root 
radius inspection. This proposed AD results from the manufacturer's 
report that some HP turbine rotor discs received improperly machined 
radii in the root of the forward and aft curvic teeth during 
manufacture. We are proposing this AD to prevent uncontained failure of 
the HP turbine rotor assembly and damage to the airplane.

DATES: We must receive any comments on this proposed AD by November 5, 
2007.

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: 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.
     Fax: (202) 493-2251.
     You can get the service information identified in this 
proposed AD from Honeywell Technical Publications and Distribution, M/S 
2101-201, P.O. Box 52170, Phoenix, AZ 85072-2170; telephone: (602) 365-
2493 (General Aviation), (602) 365-5535 (Commercial Aviation), fax: 
(602) 365-5577 (General Aviation and Commercial Aviation).
     Also, for technical support regarding the curvic root 
dimensional inspection criteria, contact the Technical Operations 
Center: telephone: (800) 601-3099 (U.S.) or (602) 365-3099 
(International) and press option 9; e-mail: 
[email protected]; or fax: (602) 365-3343.
    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: Joseph Costa, Aerospace Engineer, Los 
Angeles Aircraft Certification Office, FAA, Transport Airplane 
Directorate, 3960 Paramount Blvd., Lakewood, CA 90712-4137; e-mail: 
[email protected]; telephone: (562) 627-5246; fax: (562) 627-5210.

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-2007-27891; 
Directorate Identifier 2007-NE-14-AD'' in the subject line of your 
comments. We specifically invite comments on the overall regulatory, 
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 
DOT 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 AD docket on the Internet at http://dms.dot.gov; or in person at the Docket Operations office 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 Operations office (telephone (800) 647-5527) is the same as the 
Mail address provided in the ADDRESSES section. Comments will be 
available in the AD docket shortly after receipt.

Discussion

    In June of 2006, we became aware of a manufacturing audit that 
found that some HP turbine rotor discs, part numbers (P/Ns) 3075772-1 
and 3060841-1, received improperly machined radii in the root of the 
forward and aft curvic teeth. We have determined that the improperly 
machined radii will cause a higher stress in the curvic area of the HP 
turbine rotor disc than originally calculated. Although no reports of 
cracked HP turbine rotor discs due to improperly machined radii have 
been received, this higher stress reduces the calculated low-cycle-
fatigue life limit, to below the current published life limit. This 
condition, if not corrected, could result in uncontained failure of the 
HP turbine rotor assembly and damage to the airplane. Honeywell 
established a serial number list of suspect HP turbine rotor discs 
possibly having the improperly machined radii. This proposed AD would 
require operators to

[[Page 50649]]

send suspect HP turbine rotor discs to Honeywell for curvic root 
inspection before the discs are eligible for reinstallation in an 
engine. Since the dimensional inspection requires proprietary tooling 
and methods, Honeywell is specified as the sole provider of the curvic 
root inspections. Other repair or maintenance facilities that believe 
they are capable of conducting the inspection may apply for an 
alternative method of compliance (AMOC) in accordance with the AMOC 
paragraph in the proposed AD.

Relevant Service Information

    We have reviewed and approved the technical contents of Honeywell 
Alert Service Bulletin No. TFE731-A72-5185, dated July 5, 2006, and 
Service Bulletin No. TFE731-72-3720, dated July 5, 2006. These service 
bulletins contain the serial numbers of suspect HP turbine rotor discs, 
and describe procedures for removing the suspect HP turbine rotor 
assemblies from service.

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 
removal of certain HP turbine rotor assemblies from service using a 
drawdown schedule and returning them to Honeywell Engines, Systems, and 
Services for curvic root radius inspection. The proposed AD would 
require you to use the service information described previously to 
identify suspect HP turbine rotor discs by serial number.

Costs of Compliance

    We estimate that this proposed AD would affect 400 HP turbine rotor 
discs installed in TFE731-20R, -20AR, -20BR, -40, -40AR, -40R, and -60 
series turbofan engines, and 170 HP turbine rotor discs installed in 
TFE731-2C, -3B, -3BR, -3C, -3CR, -3D, -3DR, -4R, -5AR, -5BR, and -5R 
series turbofan engines, installed in airplanes of U.S. registry. We 
also estimate that it would take about 42 work-hours per engine to 
perform the proposed actions at an unscheduled removal, and about 2 
work-hours at a scheduled removal. The average labor rate is $80 per 
work-hour. Required parts would cost about $46,535 per engine. We 
estimate that 50 percent of the HP turbine rotor discs will fail the 
curvic root radius inspection. Based on these figures, we estimate the 
total cost of the proposed AD to U.S. operators to be $13,490,000.

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 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 AD:
    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 regulatory evaluation of the estimated costs to 
comply with this proposed AD. 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.


Sec.  39.13  [Amended]

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

Honeywell International Inc. (formerly AlliedSignal Inc. and Garrett 
Turbine Engine Co.): Docket No. FAA-2007-27891; Directorate 
Identifier 2007-NE-14-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by November 5, 
2007.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Honeywell International Inc. (Honeywell) 
TFE731-2C, -3B, -3BR, -3C, -3CR, -3D, -3DR, -4R, -5AR, -5BR, -5R, -
20R, -20AR, -20BR, -40, -40AR, -40R, and -60 series turbofan engines 
with certain high pressure (HP) turbine rotor discs part numbers and 
serial numbers. These engines are installed on, but not limited to, 
the following airplanes:

Avions Marcel Dassault Mystere-Falcon 10 and 50 Series
Cessna Model 650; Citations III, VI, and VII
Dassault-Aviation 20, 50, 50EX, 900, MF900, and 900EX (900DX) Series
Gulfstream Aerospace LP (formerly IAI) 1125 Westwind Astra, Astra SPX,
 Gulfstream 100 Series
Israel Aircraft Industries (IAI) 1124 Series (Westwind 1124)
Learjet 31, 35, 36, 45 (or Learjet 40), and 55 Series
Lockheed-Georgia 3329-25 Series (731 Jetstar, Jetstar II)
Raytheon Corporate Jets (formerly British Aerospace) Hawker 800 and 850
 Series
Sabreliner NA-265-65 (Sabreliner 65)
 

Unsafe Condition

    (d) This AD results from a report that some HP turbine rotor 
discs received improperly machined radii in the root of the forward 
and aft curvic teeth during manufacture. We are issuing this AD to 
prevent uncontained failure of the HP turbine rotor assembly and 
damage to the airplane.

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.

TFE731-2C, -3B, -3BR, -3C, -3CR, -3D, -3DR, -4R, -5AR, -5BR, and -5R 
Series Turbofan Engines

    (f) For TFE731-2C, -3B, -3BR, -3C, -3CR, -3D, -3DR, -4R, -5AR, -
5BR, and -5R series turbofan engines, remove HP turbine rotor 
assemblies from service containing HP turbine rotor discs, part 
number (P/N) 3075772-1, having any serial number (SN) in Table 1 of 
Honeywell Service Bulletin (SB) No. TFE731-72-3720, dated July 5, 
2006. Use the following drawdown schedule:

[[Page 50650]]

    (1) For HP turbine discs with 4,200 cycles-since-new (CSN) or 
more on the effective date of this AD, remove HP turbine rotor 
assemblies within 100 cycles-in-service (CIS) after the effective 
date of this AD.
    (2) For HP turbine discs with fewer than 4,200 CSN on the 
effective date of this AD, remove HP turbine rotor assemblies at the 
next access to the HP turbine rotor discs, but not to exceed 4,300 
CSN.

TFE731-20R, -20AR, -20BR, -40, -40AR, -40R, and -60 Series Turbofan 
Engines

    (g) For TFE731-20R, -20AR, -20BR, -40, -40AR, -40R, and -60 
series turbofan engines, remove HP turbine rotor assemblies from 
service containing HP turbine rotor discs, P/N 3060841-1, having any 
SN in Table 1 of Honeywell Alert SB No. TFE731-A72-5185, dated July 
5, 2006. Use the following drawdown schedule:
    (1) For HP turbine discs with 3,200 CSN or more on the effective 
date of this AD, remove HP turbine rotor assemblies within 100 CIS 
after the effective date of this AD.
    (2) For HP turbine discs with fewer than 3,200 CSN on the 
effective date of this AD, remove HP turbine rotor assemblies at the 
next access to the turbine rotor discs, but not to exceed 3,300 CSN.

For All Engines

    (h) HP turbine rotor discs removed per paragraphs (f) and (g) of 
this AD must pass a curvic root radius inspection performed by 
Honeywell Engines, Systems and Services, Phoenix, Arizona, 
Certificate Repair Station No. ZN3R030M, before the discs are 
eligible for reinstallation in an engine.
    (i) For the purposes of this AD, access to the HP turbine rotor 
discs is defined as the removal of the HP turbine rotor assembly 
from the engine.

Alternative Methods of Compliance

    (j) The Manager, Los Angeles 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) Contact Joseph Costa, Aerospace Engineer, Los Angeles 
Aircraft Certification Office, FAA, Transport Airplane Directorate, 
3960 Paramount Blvd., Lakewood, CA 90712-4137; e-mail: 
[email protected]; telephone: (562) 627-5246; fax: (562) 627-
5210, for more information about this AD.
    (l) For more information regarding the engine manufacturer's 
accomplishment instructions or material information, refer to 
Honeywell Alert SB No. TFE731-A72-5185, dated July 5, 2006, and SB 
No. TFE731-72-3720, dated July 5, 2006.

    Issued in Burlington, Massachusetts, on August 28, 2007.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. E7-17384 Filed 8-31-07; 8:45 am]
BILLING CODE 4910-13-P