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.

Proposed Rules Federal Register

62623

Vol. 69, No. 207

Wednesday, October 27, 2004

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2004–19463; Directorate 

Identifier 2004–NE–14–AD] 

RIN 2120–AA64 

Airworthiness Directives; General 

Electric Company CF6–45A, CF6–50A, 

CF6–50C, and CF6–50E 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 

General Electric Company (GE) CF6–

45A, CF6–50A, CF6–50C, and CF6–50E 

series turbofan engines that have not 

incorporated GE Service Bulletin (SB) 

No. CF6–50 S/B 72–1239, Revision 1, 

dated September 24, 2003, or that have 

not incorporated paragraph 3.B. of GE 

SB No. CF6–50 S/B 72–1239, original 

issue, dated May 29, 2003. This 

proposed AD would require inspecting 

the stage 1 low pressure turbine (LPT) 

blades for damage and replacement of 

the LPT module if necessary. This 

proposed AD results from a report of a 

stud that separated from a turbine mid 

frame (TMF) strut and from an updated 

analysis of strut stud failures. We are 

proposing this AD to prevent an 

uncontained failure of the engine and 

possible damage to the airplane caused 

by failure of TMF strut studs.

DATES: We must receive any comments 

on this proposed AD by December 27, 

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: (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 

General Electric Company via Lockheed 

Martin Technology Services, 10525 

Chester Road, Suite C, Cincinnati, Ohio 

45215, telephone (513) 672–8400, fax 

(513) 672–8422. 

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:

Karen Curtis, Aerospace Engineer, 

Engine Certification Office, FAA, Engine 

and Propeller Directorate, 12 New 

England Executive Park, Burlington, MA 

01803; telephone (781) 238–7192; fax 

(781) 238–7199.

SUPPLEMENTARY INFORMATION: 

Docket Management System (DMS) 

We have implemented new 

procedures for maintaining AD dockets 

electronically. As of May 17, 2004, we 

post new AD actions on the DMS and 

assign 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–

2004–19463; Directorate Identifier 

2004–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 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 

The FAA recently heard from GE of a 

TMF strut stud and an LPT stage 1-tostage 2 disk joint bolt failure found 

during engine disassembly. GE reported 

one strut stud failure on a first-run 

engine, and three uncontained engine 

failures in 1984 and 1985, caused by 

reused strut studs. GE also reported nine 

strut stud failures on engines removed 

for other causes. Strut stud failures can 

result in hard debris in the LPT 

flowpath and cause damage to LPT 

airfoils. Borescope inspection for 

damage to the stage 1 LPT blades can 

identify the effects of a strut stud 

separation event. Ten unscheduled 

engine removals have occurred due to 

evidence of strut stud failure. Twenty 

strut stud failures have been found 

during routine shop inspections. GE 

issued SB No. 72–0897 in March 1987 

that introduced an inspection and an 

improved strut stud configuration. Since 

that SB was issued, one uncontained 

engine failure occurred in 1996, two 

findings of stud failures on engines 

62624 Federal Register / Vol. 69, No. 207 / Wednesday, October 27, 2004 / Proposed Rules 

removed for other causes, and four 

unscheduled engine removals have 

occurred due to strut stud failures.

GE found that the cause of strut stud 

failure may be insufficient clearance 

between the LPT stage 1 nozzle support 

and the sleeve assembly that is fitted to 

the TMF. During engine operation, 

thermal growth differences can cause 

bending and reduced low-cycle-fatigue 

life of the strut studs that join the nozzle 

support to the TMF through the sleeve 

assembly. GE also found that the reuse 

of strut studs during LPT assembly can 

increase the probability of a strut stud 

failure. 

GE’s analysis shows that continued 

operation with one or more failed strut 

studs can result in LPT flow path 

damage, separation of adjacent strut 

studs, and separation of the bolts 

connecting the LPT stage 1 and stage 2 

disks. GE’s analysis also shows that 

continued operation with separated 

bolts can lead to overspeed and an 

uncontained failure of the stage 1 disk. 

This condition, if not corrected, could 

result in an uncontained failure of the 

engine and possible damage to the 

airplane. 

Relevant Service Information 

We have reviewed and approved the 

technical contents of GE Alert Service 

Bulletin (ASB) No. CF6–50 S/B 72–

A1251, dated September 24, 2003, that 

describes procedures for initial and 

repetitive borescope inspections of stage 

1 blades for damage caused by separated 

strut studs, and replacement of the LPT 

module if stage 1 LPT blade damage 

exceeds aircraft maintenance manual 

limits. 

GE CF6–45A, CF6–50A, CF6–50C, 

and CF6–50E series turbofan engines 

that have incorporated GE SB No. CF6–

50 S/B 72–1239, Revision 1, dated 

September 24, 2003, or that have 

incorporated paragraph 3.B. of GE SB 

No. CF6–50 S/B 72–1239, original issue, 

dated May 29, 2003, are exempt from 

this proposed AD. Those incorporations 

increase the clearance of the stage 1 LPT 

nozzle and the sleeve fitted to the 

turbine mid frame, which eliminates the 

cause of failure of TMF strut studs. 

Differences Between the Proposed AD 

and the Manufacturer’s Service 

Information 

GE ASB No. CF6–50 S/B 72–A1251, 

dated September 24, 2003, does not 

provide for inspection of engines that 

have already accumulated more than 

3,000 cycles-since-new (CSN) or 500 

cycles-since-last-inspection (CSLI). This 

proposed AD would allow up to 150 

cycles-in-service after the effective date 

of the AD for compliance for these 

engines. 

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 initial and 

repetitive borescope inspections of stage 

1 LPT blades for damage and 

replacement of the LPT module if 

damage exceeds aircraft maintenance 

manual limits. 

The proposed AD would require you 

to use GE ASB No. CF6–50 S/B 72–

A1251, dated September 24, 2003, to 

perform these actions. 

Costs of Compliance 

There are about 2,079 GE CF6–45A, 

CF6–50A, CF6–50C, and CF6–50E series 

turbofan engines of the affected design 

in the worldwide fleet. We estimate that 

790 engines installed on airplanes of 

U.S. registry would be affected by this 

proposed AD. We also estimate that it 

would take about one work hour per 

engine to perform the proposed actions, 

and that the average labor rate is $65 per 

work hour. Based on these figures, we 

estimate the total cost of the proposed 

AD to perform one inspection to U.S. 

operators to be $51,350. 

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 FAA 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 Federal Aviation 

Administration (FAA) amends § 39.13 

by adding the following new 

airworthiness directive (AD):

General Electric Company: Docket No. FAA–

2004–19463; Directorate Identifier 2004–

NE–14–AD. 

Comments Due Date 

(a) The FAA must receive comments on 

this AD action by December 27, 2004. 

Affected ADs 

(b) None. 

Applicability 

(c) This AD applies to General Electric 

Company (GE) CF6–45A, CF6–50A, CF6–

50C, and CF6–50E series turbofan engines 

that have not incorporated GE Service 

Bulletin (SB) No. CF6–50 S/B 72–1239, 

Revision 1, dated September 24, 2003, or that 

have not incorporated paragraph 3.B. of GE 

SB No. CF6–50 S/B 72–1239, original issue, 

dated May 29, 2003. These engines are 

installed on, but not limited to, Boeing DC10 

and 747 series airplanes, and Airbus 

Industrie A300 series airplanes. 

Unsafe Condition 

(d) This AD results from a report of a stud 

that separated from a turbine mid frame 

(TMF) strut and from an updated analysis of 

strut stud failures. We are issuing this AD to 

prevent an uncontained failure of the engine 

and possible damage to the airplane caused 

by failure of TMF strut studs. 

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. 

Initial Inspection 

(f) Borescope-inspect the low pressure 

turbine (LPT) stage 1 blades within 3,000 

cycles-since-new (CSN), or 3,000 cyclessince-replacement of the TMF strut studs, or 

150 cycles-in-service (CIS) after the effective 

date of this AD, whichever occurs later. Use 

paragraph 3.A.(2) of the Accomplishment 

Instructions of GE Alert Service Bulletin 

(ASB) No. CF6–50 S/B 72–A1251, dated 

September 24, 2003, to do the inspection. 

(g) Replace any LPT module that has stage 

1 LPT blade damage exceeding aircraft 

maintenance manual limits. 

Repetitive Inspections 

(h) Borescope-inspect the LPT stage 1 

blades within intervals of 500 cycles-sinceVerDate jul<14>2003 15:40 Oct 26, 2004 Jkt 200001 PO 00000 Frm 00002 Fmt 4702 Sfmt 4702 E:\FR\FM\27OCP1.SGM 27OCP1
Federal Register / Vol. 69, No. 207 / Wednesday, October 27, 2004 / Proposed Rules 62625

last-inspection or within 500 cycles-sincelast shop visit, or within 150 CIS after the 

effective date of this AD, whichever occurs 

later. Use paragraph 3.A.(3) of the 

Accomplishment Instructions of GE ASB No. 

CF6–50 S/B 72–A1251, dated September 24, 

2003 to do the inspections. 

(i) Replace any LPT module that has stage 

1 LPT blade damage exceeding aircraft 

maintenance manual limits. 

Optional Terminating Action 

(j) Engines incorporating GE SB No. CF6–

50 S/B 72–1239, Revision 1, dated September 

24, 2003, or incorporating paragraph 3.B. of 

GE SB No. CF6–50 S/B 72–1239, original 

issue, dated May 29, 2003, ends the repetitive 

inspection requirements in paragraph (h) of 

this AD. 

Alternative Methods of Compliance 

(k) The Manager, Engine 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 

(l) None.

Issued in Burlington, Massachusetts, on 

October 21, 2004. 

Jay J. Pardee, 

Manager, Engine and Propeller Directorate, 

Aircraft Certification Service.

[FR Doc. 04–24035 Filed 10–26–04; 8:45 am] 

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2004–19447; Directorate 

Identifier 2004–NM–97–AD] 

RIN 2120–AA64 

Airworthiness Directives; Saab Model 

SAAB SF340A and SAAB 340B Series 

Airplanes

AGENCY: Federal Aviation 

Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: The FAA proposes to adopt a 

new airworthiness directive (AD) for all 

Saab Model SAAB SF340A and SAAB 

340B series airplanes. This proposed AD 

would require a one-time inspection to 

determine the part and serial numbers 

of certain molded assembly engine 

mounts (isolators) and the cure dates of 

certain bonded canister assemblies 

incorporated in those engine mounts; 

and related corrective actions if 

necessary. This proposed AD is 

prompted by a report that disbonding of 

the elastomer from the inner metal core 

and shim of certain molded assembly 

engine mounts has occurred within a 

few hundred hours of operation, causing 

heavy chafing of the engine support 

system and chafing of the fire sensor 

loop. We are proposing this AD to 

prevent reduced integrity of the fireshielding capacity of the nacelle 

structure and a possible fire detector 

fault.

DATES: We must receive comments on 

this proposed AD by November 26, 

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. 

• By 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. 

For service information identified in 

this proposed AD, contact Saab Aircraft 

AB, SAAB Aircraft Product Support, S–

581.88, Linko ̈ping, Sweden. 

You can examine the contents of this 

AD docket on the Internet at http://

dms.dot.gov, or at the Docket 

Management Facility, U.S. Department 

of Transportation, 400 Seventh Street 

SW., Room PL–401, on the plaza level 

of the Nassif Building, Washington, DC.

FOR FURTHER INFORMATION CONTACT: 

Technical information: Dan Rodina, 

Aerospace Engineer, International 

Branch, ANM–116, FAA, Transport 

Airplane Directorate, 1601 Lind 

Avenue, SW., Renton, Washington 

98055–4056; telephone (425) 227–2125; 

fax (425) 227–1149. 

Plain language information: Marcia 

Walters, marcia.walters@faa.gov.

SUPPLEMENTARY INFORMATION: 

Docket Management System (DMS) 

The FAA has implemented new 

procedures for maintaining AD dockets 

electronically. As of May 17, 2004, new 

AD actions are posted on DMS and 

assigned a docket number. We track 

each action and assign a corresponding 

directorate identifier. The DMS AD 

docket number is in the form ‘‘Docket 

No. FAA–2004–99999.’’ The Transport 

Airplane Directorate identifier is in the 

form ‘‘Directorate Identifier 2004–NM–

999–AD.’’ Each DMS AD docket also 

lists the directorate identifier (‘‘Old 

Docket Number’’) as a cross-reference 

for searching purposes. 

Comments Invited 

We invite you to submit any relevant 

written data, views, or arguments 

regarding this proposed AD. Send your 

comments to an address listed under 

ADDRESSES. Include ‘‘Docket No. FAA–

2004–19447; Directorate Identifier 

2004–NM–97–AD’’ at the beginning 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 submitted 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 our docket 

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 can 

review the DOT’s complete Privacy Act 

Statement in the Federal Register

published on April 11, 2000 (65 FR 

19477–78), or you can 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 Docket 

You can examine the AD docket on 

the Internet at http://dms.dot.gov, or in 

person at the Docket Management 

Facility office between 9 a.m. and 5 

p.m., Monday through Friday, except 

Federal holidays. The Docket 

Management Facility office (telephone 

(800) 647–5227) is located on the plaza 

level of the Nassif Building at the DOT 

street address stated in the ADDRESSES

section. Comments will be available in 

the AD docket shortly after the DMS 

receives them. 

Discussion 

The Luftfartsverket (LFV), which is 

the airworthiness authority for Sweden,