04-14946. Airworthiness Directives; Honeywell International Inc. (Formerly AlliedSignal Inc. and Garrett Turbine Engine Co.). TFE731-2 and -3 Series Turbofan Engines

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for Honeywell International Inc. (formerly AlliedSignal Inc. and Garrett Turbine Engine Co.) TFE731-2 and -3 series turbofan engines with certain part numbers (P/Ns) and serial numbers (SNs) of low pressure (LP) 1st and 2nd stage turbine rotor discs initially installed as new parts before April 1, 1991. This proposed AD would require replacement of those LP 1st and 2nd stage turbine rotor discs. This proposed AD results from a report of an uncontained failure of an LP 2nd stage turbine rotor disc that caused an in-flight engine shutdown. We are proposing this AD to prevent LP turbine rotor disk separation, which could result in an uncontained engine failure and damage to the airplane.

DATES:

We must receive any comments on this proposed AD by August 30, 2004.

ADDRESSES:

Use one of the following addresses to submit comments 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 20590-001.
• Fax: [phone].
• 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 Honeywell Engines and Systems (formerly AlliedSignal Inc. and Garrett Turbine Engine Co.) Technical Publications and Distribution, M/S 2101-201, P.O. Box 52170, Phoenix, AZ 85072-2170; telephone: [phone] (General Aviation), [phone] (Commercial Aviation), fax: [phone] (General Aviation), [phone] (Commercial Aviation).

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; telephone: [phone]; fax: [phone].

SUPPLEMENTARY INFORMATION:

Docket Management System (DMS)

We have implemented new procedures for maintaining AD dockets electronically. As of May 17, 2004, we posted new AD actions on the DMS and assigned a DMS docket number. We track each action and assign a corresponding Directorate identifier. The DMS docket No. is in the form “Docket No. FAA-200X-XXXXX.” Each DMS docket also lists the Directorate identifier (“Old Docket Number”) as a cross-reference for searching purposes.

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 “Docket No. FAA-2004-18496; Directorate Identifier 2004-NE-04-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 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.

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 can 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 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 [phone]) 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

Honeywell International Inc. has made the FAA aware that a problem may exist with LP 1st and 2nd stage turbine rotor discs manufactured from 1981 through 1984 that were heat treated in an oil fired furnace. This heat treat process might have resulted in turbine rotor disc material with nonuniform microstructure, which is susceptible to cracking and/or separation. On March 22, 1995, we issued AD 95-07-02 (60 FR 19343, April 18, 1995) that requires removing suspect LP turbine rotor discs due to their suspect heat treatment and susceptibility to creep fatigue. At that time, a total of five LP 2nd stage turbine rotor discs had failed.

Since AD 95-07-02 was issued, a sixth LP 2nd stage turbine rotor disc failed, causing an in-flight engine shutdown. Analysis revealed that the disc was from a manufacturing lot that was originally not suspect for defects, and revealed that the disc had nonuniform microstructure similar to the LP turbine rotor disc lots identified by AD 95-07-02. This condition, if not corrected, could result in LP turbine rotor disk separation, which may result in an uncontained engine failure and damage to the airplane.

Relevant Service Information

We have reviewed and approved the technical contents of Honeywell International Inc. Service Bulletin (SB) No. TFE731-72-3682, dated November 26, 2002, that describes procedures for replacement of specific serial numbered LP 1st and 2nd stage turbine rotor discs manufactured before April 1, 1991.

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

There are differences between this proposed AD and SB No. TFE731-72-3682, dated November 26, 2002, in identifying the suspect serial numbers with respect to the engine model number. These differences result from LP 1st and 2nd stage turbine rotor discs previously identified in AD 95-07-02.

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 the following for Honeywell International Inc. TFE731-2 and -3 series turbofan engines:

• The following actions are applicable to the P/Ns of LP 1st and 2nd stage turbine rotor discs listed in the applicability section of the proposed AD that were initially installed as new parts before April 1, 1991, and that have SNs listed in Tables 1, 2, and 3 of Honeywell International Inc. Service Bulletin (SB) No. TFE731-72-3682, dated November 26, 2002.
• For TFE731-2-2J, TFE731-2-2N, TFE731-2A-2A, and TFE731-3-1J engines, within 100 hours time-in-service (TIS) after the effective date of this proposed AD, replace discs that are listed by SN in Tables 1 and 3 of Honeywell International Inc. SB No. TFE731-72-3682, dated November 26, 2002.
• For TFE731-2 series engines except TFE731-2-2J, TFE731-2-2N, and TFE731-2A-2A engines, replace discs that are listed by SN in Tables 1 and 2 of Honeywell International Inc. SB No. TFE731-72-3682, dated November 26, 2002, at the next Major Periodic Inspection (MPI) or next access to the turbine discs after the effective date of this AD, but within 2,200 hours TIS since the last disc inspection, whichever occurs first.
• For TFE731-3 series engines except TFE731-3-1J, replace discs that are listed by SN in Table 3 of Honeywell International Inc. SB No. TFE731-72-3682, dated November 26, 2002, at the next MPI or next access to the turbine discs after the effective date of this AD, but within 1,500 hours TIS since the last disc inspection, whichever occurs first.
• After the effective date of this proposed AD, do not install any LP 1st and 2nd stage turbine rotor disc that has a SN listed in Table 1, 2, or 3 of SB No. TFE731-72-3682, dated November 26, 2002, and determined to be manufactured before April 1, 1991.

Costs of Compliance

There are about 56 Honeywell International Inc. TFE731-2 and -3 series turbofan engines of the affected design in the worldwide fleet. We estimate that 24 engines installed on airplanes of U.S. registry would be affected by this proposed AD. We also estimate that it would take about 4 work hours per engine to perform the proposed actions, and that the average labor rate is $65 per work hour. Required parts would cost about $30,000 per engine. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $726,240.

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.

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.

§ 39.13

[Amended]

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

Honeywell International Inc. (formerly AlliedSignal Inc. and Garrett Turbine Engine Co.): Docket No. FAA-2004-18496; Directorate Identifier 2004-NE-04-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by August 30, 2004.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Honeywell International Inc. (formerly AlliedSignal Inc. and Garrett Turbine Engine Co.) TFE731-2 and -3 series turbofan engines with the following low pressure (LP) 1st and 2nd stage turbine rotor disc part numbers (P/Ns), with serial numbers (SNs) listed in Tables 1, 2, and 3 of Honeywell International Inc. SB No. TFE731-72-3682, dated November 26, 2002, initially installed as new parts before April 1, 1991:

3072069-All

3072070-All

3072351-All

3072542-All

3073013-All

3073014-All

3073113-All

3073114-All

3074103-All

3074105-All

(All denotes all dash numbers installed)

These engines are installed on, but not limited to, the following airplanes:

Avions Marcel Dassault Mystere-Falcon 10 and 50 series

Cessna Model 650, Citation III, and Citation VI

Gulfstream Aerospace LP (formerly IAI) 1125 Westwind Astra series

Israel Aircraft Industries (IAI) 1124 series

Learjet 31, 35, 36, and 55 series

Lockheed-Georgia 1329-25 series (731 Jetstar, Jetstar II)

Raytheon Corporate Jets (formerly British Aerospace) DH/HS/BH-125 series;

Sabreliner NA-265-65 (Sabreliner 65)

Unsafe Condition

(d) This AD results from a report of an uncontained failure of an LP 2nd stage turbine rotor disc that caused an in-flight engine shutdown. We are issuing this AD to prevent LP turbine rotor disk separation, which could result in an uncontained engine failure 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.

Removal From Service of LP 1st and 2nd Stage Turbine Rotor Discs

(f) For TFE731-2-2J, TFE731-2-2N, TFE731-2A-2A, and TFE731-3-1J engines, replace discs that are listed by SN in Tables 1 and 3 of SB No. TFE731-72-3682, dated November 26, 2002, within 100 hours time-in-service (TIS) after the effective date of this AD.

(g) For TFE731-2 series engines except TFE731-2-2J, TFE731-2-2N, and TFE731-2A-2A engines, replace discs that are listed by SN in Tables 1 and 2 of SB No. TFE731-72-3682, dated November 26, 2002, at the next Major Periodic Inspection (MPI) or next access to the turbine discs after the effective date of this AD, but within 2,200 hours TIS since the last disc inspection, whichever occurs first.

(h) For TFE731-3 series engines except TFE731-3-1J, replace discs that are listed by SN in Table 3 of SB No. TFE731-72-3682, dated November 26, 2002, at the next MPI or next access to the turbine discs after the effective date of this AD, but within 1,500 hours TIS since the last disc inspection, whichever occurs first.

(i) Information on replacing affected discs can be found in Honeywell International Inc. SB No. TFE731-72-3682, dated November 26, 2002.

(j) After the effective date of this AD, do not install any LP 1st and 2nd stage turbine rotor disc that has a SN listed in Table 1, 2, or 3 of SB No. TFE731-72-3682, dated November 26, 2002, and determined to be manufactured before April 1, 1991.

Definitions

(k) For the purposes of this AD, access to the turbine discs is the level of disassembly that has removed the tie-shaft nut.

Alternative Methods of Compliance

(l) 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.

Material Incorporated by Reference

(m) None.

Related Information

(n) None.

Issued in Burlington, Massachusetts, on June 24, 2004.

Jay J. Pardee,

Manager, Engine and Propeller Directorate, Aircraft Certification Service.