Airworthiness Directives; Honeywell International Inc., (Formerly AlliedSignal, Inc. and Textron Lycoming) ALF502L Series and ALF502R Series Turbofan Engines

Summary:

The FAA proposes to supersede an existing airworthiness directive (AD), AD 95-04-11, for Honeywell International Inc., (formerly AlliedSignal, Inc. and Textron Lycoming) ALF502L series and ALF502R series turbofan engines. That AD currently establishes stress rupture retirement life limits for certain third stage turbine discs used in conjunction with certain third stage turbine nozzles. This proposed AD would bring requirements forward and unchanged, from the previous AD for ALF502R series turbofan engines. Also, this proposed AD would establish new reduced stress rupture retirement life limits for certain part numbers (P/Ns) of third stage turbine disc and shaft assemblies installed in ALF502L series turbofan engines. This proposed AD would also require removing those same parts from service using a drawdown schedule. This proposed AD results from a report of failure of a third stage turbine disc and shaft assembly, leading to turbine blade release and separation of the exhaust nozzle. We are proposing this AD to prevent total loss of engine power, in-flight engine shutdown, release of turbine blades, separation of the exhaust nozzle, and possible damage to the airplane.

Table of Contents

Table of Figures

Dates:

We must receive any comments on this proposed AD by January 3, 2006.

Addresses:

Use one of the following addresses to comment on this proposed AD:

• By mail: Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 92-ANE-34-AD, 12 New England Executive Park, Burlington, MA 01803-5299.

• By fax: (781) 238-7055.

• By e-mail:9-ane-adcomment@faa.gov.

Contact Honeywell Engines, Systems Services, Customer Support Center, M/S 26-06/2102-323, P.O. Box 29003, Phoenix, AZ 85038-9003; telephone (800) 601-3099, for the service information identified in this proposed AD.

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:

Robert Baitoo, Aerospace Engineer, Los Angeles Aircraft Certification Office, FAA, Transport Airplane Directorate, 3960 Paramount Blvd., Lakewood, CA 90712-4137; telephone: (562) 627-5245, fax: (562) 627-5210.

Supplementary information:

Comments Invited

We invite you to send any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “AD Docket No. 92-ANE-34-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 bythe closing date and may amend the proposed AD in light of those comments.

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 March 2, 1995, we issued AD 95-04-11, Amendment 39-9163 (60 FR 11621, April 3, 1995), applicable to ALF502L series and ALF502R series turbofan engines. That AD established stress rupture retirement life limits for certain third stage turbine discs used in conjunction with certain third stage turbine nozzles. That AD resulted from introduction of an improved design third stage turbine nozzle, and a new reduced stress rupture retirement life limit for certain third stage turbine discs on the ALF502L series engines. That condition, if not corrected, could result in total loss of engine power, in-flight engine shutdown, and possible damage to the airplane.

Actions Since AD 95-04-11 Was Issued

Since we issued that AD, we received a report of a third stage turbine disc and shaft assembly failure in an ALF502L-2C engine. The rim of the disc ruptured during airplane climb, resulting in release of turbine blades and separation of the exhaust nozzle. Honeywell International Inc. has also cited several other separation incidents of third stage turbine blades, resulting in airplane and engine damage. The third stage turbine disc and shaft assemblies involved in these events were all of the Honeywell Pre SB No. ALF502L 72-232 configuration.

Relevant Service Information

We have reviewed and approved the technical contents of Honeywell International Service Bulletin (SB) No. ALF502 72-0004, Revision 17, dated January 16, 2005. That SB establishes new reduced service life limits for third stage turbine disc and shaft assemblies installed in ALF502L series turbofan engines that have operated in the Pre SB No. ALF502L 72-232 configuration. That SB also describes procedures for calculating the remaining service life of certain third stage turbine disc and shaft assemblies that have operated in Pre and Post SB No. ALF502L 72-232 configurations.

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:

• Bringing requirements forward and unchanged from AD 95-04-11 for ALF502R series turbofan engines; and

• For ALF502L series turbofan engines, establishing new reduced service life limits for third stage turbine disc and shaft assemblies, P/N 2-143-030-05; P/N 2-143-030-08; P/N 2-143-030-14; P/N 2-143-030-R21; P/N 2-143-030-22; and P/N 2-143-030-23, that have operated in the Honeywell Pre SB No. ALF502L 72-232 configuration; and

• Removing those same parts from service using a drawdown schedule.

• Limiting the special flight permits for this AD by allowing a onetime special flight if the disc life limit has been reached.

The proposed AD would require that you calculate the remaining service life of certain third stage turbine disc and shaft assemblies using the service information described previously.

Costs of Compliance

There are about 180 Honeywell International, Inc. ALF502L, ALF502L-2, ALF502L-2A, ALF502L-2C, ALF502L-3, and ALF502R series turbofan engines of the affected design in the worldwide fleet. We estimate the proposed AD would affect 170 engines installed on airplanes of U.S. registry. We also estimate that it would take about 14 work hours per engine to perform the proposed actions, and that the average labor rate is $65 per work hour. The prorated cost of a replacement third stage turbine disc and shaft assembly is estimated to be $40,000. Based on these figures, we estimate the total labor cost of the proposed AD on U.S. operators to be $6,954,700.

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 by sending a request to us at the address listed under ADDRESSES. Include “AD Docket No. 92-ANE-34-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.

§ 39.13

2. The FAA amends § 39.13 by removing Amendment 39-9163 (60 FR 11621, April 3, 1995) and by adding a new airworthiness directive to read as follows:

Honeywell International Inc. (formerly AlliedSignal, Inc. and Textron Lycoming): Docket No. 92-ANE-34-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by January 3, 2006.

Affected ADs

(b) This AD supersedes AD 95-04-11, Amendment 39-9163.

Applicability

(c) This AD applies to Honeywell International Inc., (formerly AlliedSignal, Inc. and Textron Lycoming) ALF502L, ALF502L-2, ALF502L-2A, ALF502L-2C, and ALF502L-3 series turbofan engines with third stage turbine disc and shaft assemblies that have operated in the Honeywell Pre SB No. ALF502L 72-232 configuration. This AD also applies to ALF502R series engines. These engines are installed on, but not limited to, BAe Systems AVRO 146 and Bombardier (Canadair) CL600-1A11 series airplanes.

Unsafe Condition

(d) This AD results from a report of failure of a third stage turbine disc and shaft assembly, leading to turbine blade release and separation of the exhaust nozzle. We are issuing this AD to prevent total loss of engine power, in-flight engine shutdown, release of turbine blades, separation of the exhaust nozzle, and possible 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.

ALF502LSeries Turbofan Engines

Determination of Third Stage Turbine Disc and Shaft Assembly Drawdown Schedule

(f) For ALF502L series turbofan engines, determine if the third stage turbine disc and shaft assembly is currently operating in the Pre SB No. ALF502L 72-232 configuration as follows:

(1) If third stage turbine nozzle assembly, part number (P/N) 2-141-120R56/-57 is installed, then Honeywell SB No. ALF502L 72-232 has been complied with. Proceed to the drawdown schedule in paragraph (h) of this AD.

(2) If any other third stage turbine nozzle assembly is installed, then the engine is in the Pre SB No. ALF502L 72-232 configuration. Proceed to the drawdown schedule in paragraph (g) of this AD.

Drawdown Schedule for Third Stage Turbine Disc and Shaft Assemblies That Are Operating in the Pre SB No. ALF502L 72-232 Configuration

(g) For ALF502L series turbofan engines, use the drawdown schedule described in the following Table 1, and replace with serviceable parts:

Table 1.—Drawdown Schedule for Third Stage Turbine Disc and Shaft Assemblies In Pre SB ALF502L 72-232 Configuration
For third stage turbine disc and shaft assembly P/NsIf hours-in-service (HIS) on the effective date of this AD areThen remove
2-143-030-05 (1) 5,200 or more HIS Within 50 additional HIS.
2-143-030-08 (2) 5,001 to 5,199 HIS Before reaching 5,250 HIS.
2-143-030-14 (3) 2,551 to 5,000 HIS Within 250 additional HIS.
2-143-030R21 (4) 2,550 or fewer HIS Before reaching 2,800 HIS.
2-143-030-22
2-143-030-23

Determination of Drawdown Schedule for Third Stage Turbine Disc and Shaft Assemblies That Have Operated in Pre and Post SB No. ALF502L 72-232 Configurations

(h) For ALF502L series turbofan engines, with third stage turbine disc and shaft assemblies converted from Pre SB No. ALF502L 72-232 configuration to Post SB No. ALF502L 72-232 configuration, do the following:

(1) Determine the total HIS accumulated on the third stage turbine disc and shaft assembly at time of installation of third stage turbine nozzle assembly, P/N 2-141-120-R56/-57.

(2) If the total is 2,800 HIS or more, use the drawdown schedule in Table 1 of this AD to remove the assembly from service.

(3) If the total is fewer than 2,800 HIS, calculate the remaining service life using paragraphs 2.A. through 2.B.(4)(i) of the Accomplishment Instructions of Honeywell SB No. ALF502 72-0004, Revision 17, dated January 16, 2005.

(i) For ALF502L series turbofan engines, use the drawdown schedule described in the following Table 2 to remove the assembly from service:

Table 2.—Drawdown Schedule for Third Stage Turbine Disc and Shaft Assemblies Operated In Pre and Post SB No. ALF502L 72-232 Configuration
For third stage turbine disc and shaft assembly part numbers:If HIS on the effective date of this AD are:Then:
(1) 2-143-030-05,2-143-030-08,2-143-030-14 (i) 30,000 or more HIS Remove within 50 additional HIS.
(ii) 27,250 to 29,999 HIS Remove within 250 additional HIS.
(iii) Fewer than 27, 250 HIS Remove using Tables 1 through 5 of Honeywell SB No. ALF502 72-0004, Revision 17, dated January 16, 2005.
(2) 2-143-030R21, 2-143-030-23 (i) 24,650 or more HIS Remove within 50 additional HIS.
(ii) 22,150 to 24,649 HIS Remove within 250 additional HIS.
(iii) Fewer than 22,150 HIS Remove using Tables 1 through 5 of Honeywell SB No. ALF502 72-0004, Revision 17, dated January 16, 2005.
(3) 2-143-030-22 (i) 50,000 or more HIS Remove within 50 additional HIS.
(ii) 49,750 to 49,999 HIS Remove within 250 additional HIS.
(iii) Fewer than 49,750 HIS Remove using Tables 1 through 5 of Honeywell SB No. ALF502 72-0004, Revision 17, dated January 16, 2005.

ALF502R Series Turbofan Engines

Requirements Brought Forward, and Unchanged From AD 95-04-11

(j) For ALF502R series turbofan engines, remove from service and replace with a serviceable part third stage turbine disks, P/Ns 2-143-030-05, 2-143-030-08, and 2-143-030-14, as follows:

(1) For disks that have been installed only with third stage turbine nozzles P/Ns 2-141-130-52 or 2-141-120-53, remove from service as follows:

(i) For disks that have accumulated 13,220 or more hours time in service (TIS) since new on April 13, 1995 (the effective date of AD 95-04-11), within the next 80 hours TIS after December 11, 1990, but not to exceed the existing cyclic life limit.

(ii) For disks that have accumulated less than 13,220 hours TIS since new on April 13, 1995, before accumulating more than 13,300 hours TIS since new, but not to exceed the existing cyclic life limit.

(iii) Thereafter, remove disks before accumulating more than 13,300 hours TIS since new, but not to exceed the existing cyclic life limit.

(2) For disks that have been installed only with third stage turbine nozzles, P/Ns 2-141-120-57 or 2-141-120-R56, remove from service as follows:

(i) For disks that have accumulated 27,420 or more hours TIS since new on April 13, 1995, within 80 hours TIS after April 13, 1995, but not to exceed the existing cyclic life limit.

(ii) For disks that have accumulated less than 27,420 hours TIS since new on April 13, 1995, before accumulating more than 27,500 hours TIS since new, but not to exceed the existing cyclic life limit.

(iii) Thereafter, remove disks before accumulating more than 27,500 hours TIS since new, but not to exceed the existing cyclic life limit.

(3) For disks that have been installed with both third stage turbine nozzles, P/Ns 2-141-120-52 or 2-141-120-120-53, and third stage turbine nozzles P/Ns 2-141-120-57 or 2-141-120-R56, remove from service as follows:

(i) Determine the prorated hourly life limit using the procedure defined in the Accomplishment Instructions, Section 2.B.(2) of Textron Lycoming SB No. ALF502 72-0002, Revision 22, dated December 21, 1992. From this prorated hourly life limit, subtract 80 hours TIS to determine the compliance threshold.

(ii) For disks that have equaled or exceeded the compliance threshold on April 13, 1995, within the next 80 hours TIS, but not to exceed the existing cyclic life limit.

(iii) For disks that have accumulated fewer than the compliance threshold on April 13, 1995, before accumulating more than the calculated prorated hourly life limit.

(iv) Thereafter, remove disks at or before accumulating the prorated hourly life limit, but not to exceed the existing cyclic life limit.

Alternative Methods of Compliance

(k) 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.

Special Flight Permits

(l) Under 14 CFR part 39.23, we are limiting the special flight permits for this AD by allowing a onetime special flight if the disc life limit has been reached.

Related Information

(m) Honeywell SB No. ALF/LF A72-1085, Revision 1, dated January 16, 2005, pertains to the subject of this AD.

Issued in Burlington, Massachusetts, on October 27, 2005. Peter A. White,

Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service.

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