Federal Register / Vol. 72, No. 77 / Monday, April 23, 2007 / Proposed Rules 20075 

Related Information 

(h) Refer to MCAI European Aviation 

Safety Agency (EASA) Emergency AD No.: 

2006–0373R1–E, dated December 15, 2006, 

corrected January 5, 2007; and STEMME F & 

D SB A31–10–078, Am.-index: 01.a, dated 

November 6, 2006, for related information. 

Issued in Kansas City, Missouri, on April 

17, 2007. 

Charles L. Smalley, 

Acting Manager, Small Airplane Directorate, 

Aircraft Certification Service. 

[FR Doc. E7–7642 Filed 4–20–07; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2007–27229; Directorate 

Identifier 2007–NE–03–AD] 

RIN 2120–AA64 

Airworthiness Directives; CFM 

International, S.A. CFM56–7B Series 

Turbofan Engines 

AGENCY: Federal Aviation 

Administration (FAA), Department of 

Transportation (DOT). 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: The FAA proposes to adopt a 

new airworthiness directive (AD) for 

CFM International, S.A. CFM56–7B 

Series Turbofan Engines. This proposed 

AD would require revising the 

Airworthiness Limitations Section 

(ALS) in the Engine Shop Manual (ESM) 

and the air carrier’s approved 

continuous airworthiness maintenance 

program (CAMP) to add mandatory 

inspections of certain low pressure 

turbine rear frames (TRFs) to the ALS or 

CAMP. This proposed AD results from 

a refined lifing analysis by the engine 

manufacturer that shows the need to 

identify an initial threshold for 

inspecting certain TRFs. We are 

proposing this AD to prevent failure of 

the TRF from low-cycle fatigue cracks. 

Failure of the TRF could result in 

engine separation from the airplane, 

which could lead to loss of control of 

the airplane. 

DATES: We must receive any comments 

on this proposed AD by June 22, 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: 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 may examine the comments on 

this proposed AD in the AD docket on 

the Internet at http://dms.dot.gov. 

FOR FURTHER INFORMATION CONTACT: 

Colleen M. D’Alessandro, Aerospace 

Engineer, Engine Certification Office, 

FAA, Engine and Propeller Directorate, 

12 New England Executive Park, 

Burlington, MA 01803; telephone (781) 

238–7133; fax (781) 238–7199. 

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–

2007–27229; Directorate Identifier 

2007–NE–03–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 docket that 

contains the proposal, any comments 

received and, any final disposition in 

person at the DOT 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 

Docket Management Facility receives 

them. 

Discussion 

This AD is required because TRFs, 

part numbers 340–166–205–0, 340–166–

206–0, 340–166–207–0, 340–166–208–0, 

340–166–209–0, 340–166–210–0, now 

require an initial inspection threshold of 

25,000 cycles-in-service (CIS) on the 

commercial (air carrier) models engines 

and 19,000 CIS on the business jet 

models. This proposed AD would not 

affect any other CFM56–7B part number 

TRFs. We have been monitoring CFM’s 

revised life analysis progress since 

February 2005. CFM International 

provided to us the November 15, 2006 

revision to the ESM to introduce 

mandatory inspections of the TRF. CFM 

International has been using a damage 

tolerant lifing approach, based on an 

FAA approved methodology for 

structural lifed components, to prepare 

life extensions for all CFM56 TRFs 

using on-condition life management. 

This improved life management process 

defines a first inspection threshold and 

reinspection intervals accounting for 

crack initiation and propagation. The 

previous life management process was 

based on crack initiation only. This 

condition, if not corrected, could result 

in failure of the TRF from low-cycle 

fatigue cracks. Failure of the TRF could 

result in engine separation from the 

airplane, which could lead to loss of 

control of the airplane. 

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 revising the 

Airworthiness Limitations Section in 

the ESM and the air carrier’s approved 

continuing airworthiness maintenance 

program to incorporate life reductions 

for certain TRFs. 

Costs of Compliance 

We estimate that this proposed AD 

would affect 1,228 engines installed on 

airplanes of U.S. registry. Since life 

extensions are possible on condition, 

the cost of the proposed AD will be 

limited to performing TRF inspections. 

We also estimate that it would take 

about 3.0 work-hours per engine to 

perform the proposed actions, including 


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20076 Federal Register / Vol. 72, No. 77 / Monday, April 23, 2007 / Proposed Rules 

the TRF inspections, and that the 

average labor rate is $80 per work-hour. 

There are no required parts. Based on 

these figures, we estimate the total cost 

of the proposed AD to U.S. operators to 

be $294,720. 

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 regulatory evaluation 

of the estimated costs to comply with 

this proposed AD. See the ADDRESSES

section for a location to examine the 

regulatory evaluation. 

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: 

CFM International: Docket No. FAA–2007–

27229; Directorate Identifier 2007–NE–

03–AD. 

Comments Due Date 

(a) The Federal Aviation Administration 

(FAA) must receive comments on this 

airworthiness directive (AD) action by June 

22, 2007. 

Affected ADs 

(b) None. 

Applicability 

(c) This AD applies to CFM International 

CFM56–7B18, –7B20, –7B22, –7B24, –7B26, 

–7B27, –7B22/B1, –7B24/B1, –7B26/B1, 

–7B27/B1, –7B22/B2, –7B26/B2, –7B27/B3 

turbofan engines with Turbine Rear Frame 

(TRF), part numbers 340–166–205–0, 340–

166–206–0, 340–166–207–0, 340–166–208–0, 

340–166–209–0, 340–166–210–0, installed. 

These engines are installed on, but not 

limited to, Boeing 737 series airplanes. 

Unsafe Condition 

(d) This proposed AD results from a 

refined lifing analysis by the engine 

manufacturer that shows the need to identify 

an initial threshold for inspecting certain 

TRFs. We are proposing this AD to prevent 

failure of the TRF from low-cycle fatigue 

cracks. Failure of the TRF could result in 

engine separation from the airplane, which 

could lead to loss of control of the airplane. 

Compliance 

(e) You are responsible for having the 

actions required by this AD performed within 

30 days after the effective date of this AD, 

unless the actions have already been done. 

Mandatory Inspections 

(f) Within the next 30 days after the 

effective date of this AD, revise the 

applicable inspection program for the 

Business Jet and Air Carrier engine models 

by adding the Mandatory Inspection Intervals 

as specified in this AD, and revise the 

Airworthiness Limitations Section (chapter 

05–21–03) of the CFM56–7B Engine Shop 

Manual, CFMI–TP–SM.10 by adding the 

following: 

‘‘TURBINE REAR FRAME WITH 

TANGENTIAL STRUTS—MANDATORY 

INSPECTIONS—LIFE LIMITS 

TASK 05–21–03–200–001 

1. General 

A. This procedure gives the FAA and 

EASA mandatory Eddy Current inspection 

intervals for the turbine rear frame with 

tangential struts. The inspection uses: 

—A threshold limit, 

—Inspection intervals, 

B. The threshold limit is the timing of the 

first required inspection. First inspection 

must be done before that part has reached the 

threshold number of flight cycles. 

C. The inspection intervals specify the 

timing of inspections to be done after the 

threshold inspection has been reached. 

Inspections are repetitive without any limit. 

2. Mandatory Inspection Intervals for the 

Critical Areas of the Turbine Rear Frame with 

Tangential Struts (4 Mount Struts, No. 1, 2, 

15, and 16). 

C. Turbine Rear Frame Part Numbers 340–

166–205–0, 340–166–206–0, 340–166–207–0, 

340–166–208–0, 340–166–209–0, 340–166–

210–0, for all CFM56–7B SAC engine models 

(except –7B27A engine models). Refer to 

figure 805. 

Figure 

index No. Inspection location Inspection threshold (cycles since new) 

Inspection intervals 

(cycles) 

Inspection 

reference 

805 .......... Strut/outer ring fillet radius on 

trailing edge (A).

25,000* for –7B SAC (except 

business jet) engine models.

Refer to Figure 806* for –7B 

SAC commercial applications.

Refer to SB 72–0579*. 

Strut/outer ring fillet radius on 

leading edge (B).

19,000* for –7B SAC business 

jet engine models.

Refer to Figure 807* for –7B 

SAC business jet applications.

Strut/outer ring fillet radius on 

trailing edge (C1 below outer 

ring).

Strut/outer ring fillet radius on 

trailing edge (C2 above 

outer ring).

Note: * Applicable to all inspection locations. If inspection is not performed, part must be removed. 


pwalker on PROD1PC71 with PROPOSALS
Federal Register / Vol. 72, No. 77 / Monday, April 23, 2007 / Proposed Rules 20077 

Turbine Rear Frame with Tangential struts P/ 

N 340-166-205-0, 340-166-206-0, 340-166- 

207-0, 340-166-208-0, 340-166-209-0, 340- 

166-210-0–Areas to Be Inspected 

Figure 805, 

MANDATORY INSPECTION INTERVAL 

FOR TURBINE REAR FRAME P/N 340–166–

205/206/207/208/209/210–0 

IF NO CRACK IS FOUND ON ANY OF 

THE FOUR MOUNT STRUTS, THE 

TURBINE REAR FRAME IS SERVICEABLE 

AND MUST BE RE-INSPECTED AT 4,700 

CYCLE REPETITIVE INTERVALS. IF 

CRACKS ARE FOUND ON THE MOUNT 

STRUTS, THE TRF MUST BE REINSPECTED ACCORDING TO THE 

FOLLOWING REPETITIVE INTERVALS 

Total cumulated crack length at each location Re-inspect within 

L < 0.20 (5) ............................................................................................... 4,700. 

0.20 (5) ≤ L < 0.28 (7) .............................................................................. 3,300. 

0.28 (7) ≤ L < 0.39 (10) ............................................................................ 1,300. 

0.39 (10) ≤ L < 0.59 (15) .......................................................................... 700. 

0.59 (15) ≤ L < 0.79 (20) .......................................................................... 120. 

L ≥ 0.79 (20) ............................................................................................. IMMEDIATELY REMOVE THE TURBINE FRAME. 


pwalker on PROD1PC71 with PROPOSALSEP23AP07.004</GPH>
20078 Federal Register / Vol. 72, No. 77 / Monday, April 23, 2007 / Proposed Rules 

DURING EACH INSPECTION, ALL THE 

LOCATIONS MUST BE INSPECTED. IF 

CRACKS ARE FOUND AT DIFFERENT 

LOCATIONS, THE REPETITIVE 

INSPECTION INTERVAL IS THE MINIMUM 

INTERVAL CORRESPONDING TO THE 

MAX. CUMULATED CRACK LENGTHS. 

NOTE: DIMENSIONS ARE IN INCHES 

WITH MILLIMETERS IN PARENTHESES. 

Inspection Intervals for –7B SAC (Except 

Business Jet) Engine Models 

Figure 806 

MANDATORY INSPECTION INTERVAL 

FOR TURBINE REAR FRAME P/N 340–166–

205/206/207/208/209/210–0 

IF NO CRACK IS FOUND ON ANY OF 

THE FOUR MOUNT STRUTS, THE 

TURBINE REAR FRAME IS SERVICEABLE 

AND MUST BE RE-INSPECTED AT 3,300 

CYCLE REPETITIVE INTERVALS. IF 

CRACKS ARE FOUND ON THE MOUNT 

STRUTS, THE TRF MUST BE REINSPECTED ACCORDING TO THE 

FOLLOWING REPETITIVE INTERVALS 

Total cumulated crack length at each location Re-inspect within 

L < 0.20 (5) ............................................................................................... 3,300. 

0.20 (5) ≤ L < 0.28 (7) .............................................................................. 2,400. 

0.28 (7) ≤ L < 0.39 (10) ............................................................................ 900. 

0.39 (10) ≤ L < 0.59 (15) .......................................................................... 500. 

0.59 (15) ≤ L < 0.79 (20) .......................................................................... 80. 

L ≥ 0.79 (20) ............................................................................................. IMMEDIATELY REMOVE THE TURBINE FRAME. 

DURING EACH INSPECTION, ALL THE 

LOCATIONS MUST BE INSPECTED. IF 

CRACKS ARE FOUND AT DIFFERENT 

LOCATIONS, THE REPETITIVE 

INSPECTION INTERVAL IS THE MINIMUM 

INTERVAL CORRESPONDING TO THE 

MAX. CUMULATED CRACK LENGTHS. 

NOTE: DIMENSIONS ARE IN INCHES 

WITH MILLIMETERS IN PARENTHESES. 

Inspection Intervals for –7B SAC Business Jet 

Engine Models 

Figure 807 

(g) After the effective date of this AD, we 

will not approve any alternative inspection 

intervals for these parts except as provided 

for in paragraph (j) of this AD. 

TRFs With Unknown Cycles 

(h) If you can not establish the number of 

cycles accumulated since new, remove or 

inspect the TRF within 300 cycles-in-service 

after the effective date of this AD. The 

CFM56–7B ESM or CAMP contains 

information for inspecting the TRF. 

(i) You may install a TRF removed in 

paragraph (h) of this AD after the TRF passes 

an initial inspection for cracks. The CFM56–

7B ESM or continuous airworthiness program 

contains information on inspecting the TRF. 

Alternative Methods of Compliance 

(j) 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. 

Maintaining Records of the Mandatory 

Inspections 

(k) You have met the requirements of this 

AD by making the changes to the Engine 

Shop Manual as specified in paragraph (f) of 

this AD, and, for air carriers operating under 

part 121 of the Federal Aviation Regulations 

(14 CFR part 121), by modifying your 

continuous airworthiness maintenance plan 

to reflect those changes. You must maintain 

records of the mandatory inspections that 

result from those changes to the ALS 

according to the regulations governing your 

operation. You do not need to record each 

inspection as compliance to this AD. For air 

carriers operating under part 121, you may 

use the system established to comply with 

section 121.369. 

Related Information 

(l) CFM International Service Bulletin 

CFM56–7B S/B 72–0579, Revision 1, Dated 

October 27, 2006, contains information about 

Eddy Current inspection. 

Issued in Burlington, Massachusetts, on 

April 13, 2007. 

Peter A. White, 

Acting Manager, Engine and Propeller 

Directorate, Aircraft Certification Service. 

[FR Doc. E7–7504 Filed 4–20–07; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 71 

[Docket No. FAA–2007–27332; Airspace 

Docket No. 07–AWP–2] 

Proposed Establishment of Low 

Altitude Area Navigation Routes (TRoutes); Los Angeles, CA 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: This action proposes to 

establish three low altitude Area 

Navigation (RNAV) routes, designated 

T–245, T–247, and T–249 in the Los 

Angeles International Airport, CA, 

terminal area. T-routes are low altitude 

Air Traffic Service (ATS) routes, based 

on RNAV, for use by aircraft having 

instrument flight rules (IFR) approved 

Global Positioning System (GPS)/Global 

Navigation Satellite System (GNSS) 

equipment. The FAA is proposing this 

action to enhance safety and improve 

the efficient use of the navigable 

airspace in the Los Angeles 

International Airport, CA, terminal area. 

DATES: Comments must be received on 

or before June 7, 2007. 

ADDRESSES: Send comments on this 

proposal to the Docket Management 

System, U.S. Department of 

Transportation, Room Plaza 401, 400 

Seventh Street, SW., Washington, DC 

20590–0001. You must identify FAA 

Docket No. FAA–2007–27332 and 

Airspace Docket No. 07–AWP–2, at the 

beginning of your comments. You may 

also submit comments through the 

Internet at http://dms.dot.gov. 

FOR FURTHER INFORMATION CONTACT: Ken 

McElroy, Airspace and Rules Group, 

Office of System Operations Airspace 

and AIM, Federal Aviation 

Administration, 800 Independence 

Avenue, SW., Washington, DC 20591; 

telephone: (202) 267–8783. 

SUPPLEMENTARY INFORMATION: 

Comments Invited 

Interested parties are invited to 

participate in this proposed rulemaking 

by submitting such written data, views, 

or arguments, as they may desire. 

Comments that provide the factual basis 

supporting the views and suggestions 

presented are particularly helpful in 

developing reasoned regulatory 

decisions on the proposal. Comments 

are specifically invited on the overall 

regulatory, aeronautical, economic, 

environmental, and energy-related 

aspects of the proposal. 

Communications should identify both 

docket numbers (FAA Docket No. FAA–

2007–27332 and Airspace Docket No. 

07–AWP–2) and be submitted in 

triplicate to the Docket Management 

System (see ADDRESSES section for 

address and phone number). You may 

also submit comments through the 

Internet at http://dms.dot.gov. 

Commenters wishing the FAA to 

acknowledge receipt of their comments 

on this action must submit with those 

comments a self-addressed, stamped 


pwalker on PROD1PC71 with PROPOSALS