27592 Federal Register / Vol. 66, No. 97 / Friday, May 18, 2001 / Rules and Regulations

Applicability: Model DHC–8–100, –200,

and –300 series airplanes, certificated in any

category, having serial numbers 408, 413, 434

through 463 inclusive, 465 through 489

inclusive, 491 through 505 inclusive, and

507.

Note 1: This AD applies to each airplane

identified in the preceding applicability

provision, regardless of whether it has been

modified, altered, or repaired in the area

subject to the requirements of this AD. For

airplanes that have been modified, altered, or

repaired so that the performance of the

requirements of this AD is affected, the

owner/operator must request approval for an

alternative method of compliance in

accordance with paragraph (b) of this AD.

The request should include an assessment of

the effect of the modification, alteration, or

repair on the unsafe condition addressed by

this AD; and, if the unsafe condition has not

been eliminated, the request should include

specific proposed actions to address it.

Compliance: Required as indicated, unless

accomplished previously.

To prevent an increased risk of spreading

a fire, or failure of the cabin to pressurize

adequately if certain foam filters are

installed, accomplish the following:

Removal of Foam Filters

(a) Within 4 months after the effective date

of this AD, remove the foam filters from the

cabin ducting installation located below the

dado panels on the left- and right-hand sides

of the airplane (including verifying that the

foam filters are installed behind the grille

assemblies, inspecting the grille assemblies

on both the port and starboard sides and

along the entire length of the interior of the

airplane, removing all foam filters and

ensuring that no pieces remain, and

reinstalling the grille assemblies by locating

the fasteners and pressing each with a

quarter-turn), per Bombardier Aerospace

Repair Drawing RD8–21–23, Issue 2, dated

December 16, 1999.

Alternative Methods of Compliance

(b) An alternative method of compliance or

adjustment of the compliance time that

provides an acceptable level of safety may be

used if approved by the Manager, New York

Aircraft Certification Office (ACO), FAA.

Operators shall submit their requests through

an appropriate FAA Principal Maintenance

Inspector, who may add comments and then

send it to the Manager, New York ACO.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the New York ACO.

Special Flight Permits

(c) Special flight permits may be issued in

accordance with §§ 21.197 and 21.199 of the

Federal Aviation Regulations (14 CFR 21.197

and 21.199) to operate the airplane to a

location where the requirements of this AD

can be accomplished.

Incorporation by Reference

(d) The actions shall be done in accordance

with Bombardier Aerospace Repair Drawing

RD8–21–23, Issue 2, dated December 16,

1999, which contains the following list of

effective pages:

Page No.

Revision

Level shown

on page

Date shown on

page

1 ............... 2 Dec. 16, 1999.

2 ............... 1 Dec. 18, 1998.

3 ............... 2 Dec. 16, 1999.

(Only page 1 contains the issue date of the

drawing; no other page contains this

information.) This incorporation by reference

was approved by the Director of the Federal

Register in accordance with 5 U.S.C. 552(a)

and 1 CFR part 51. Copies may be obtained

from Bombardier, Inc., Bombardier Regional

Aircraft Division, 123 Garratt Boulevard,

Downsview, Ontario M3K 1Y5, Canada.

Copies may be inspected at the FAA,

Transport Airplane Directorate, 1601 Lind

Avenue, SW., Renton, Washington; or at the

FAA, New York Aircraft Certification Office,

10 Fifth Street, Third Floor, Valley Stream,

New York; or at the Office of the Federal

Register, 800 North Capitol Street, NW., suite

700, Washington, DC.

Note 3: The subject of this AD is addressed

in Canadian airworthiness directive CF–

2000–25, dated August 28, 2000.

Effective Date

(e) This amendment becomes effective on

June 22, 2001.

Issued in Renton, Washington, on May 8,

2001.

Donald L. Riggin,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 01–12007 Filed 5–17–01; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001–NE–05–AD; Amendment

39–12233; AD 2001–10–07]

RIN 2120–AA64

Airworthiness Directives; General

Electric Co. CF6–80C2 Turbofan

Engines

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule.

SUMMARY: This amendment adopts a

new airworthiness directive (AD), that is

applicable to General Electric Co. (GE)

CF6–80C2 turbofan engines with certain

stage 1 high pressure turbine (HPT)

rotor disks installed. This amendment

requires initial and repetitive

inspections of certain HPT rotor disks

for cracks in the bottom of the dovetail

slot. This amendment is prompted by a

report of an uncontained failure of an

engine during a high-power ground run

for maintenance. The actions specified

by this AD are intended to detect cracks

in the bottoms of the dovetail slots that

could propagate to failure of the disk

and cause an uncontained engine

failure.

DATES: Effective date June 18, 2001. The

incorporation by reference of certain

publications listed in the regulations is

approved by the Director of the Federal

Register as of June 18, 2001.

ADDRESSES: The service information

referenced in this AD may be obtained

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. This information

may be examined at the Federal

Aviation Administration (FAA), New

England Region, Office of the Regional

Counsel, 12 New England Executive

Park, Burlington, MA; or at the Office of

the Federal Register, 800 North Capitol

Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Ann

Mollica, Aerospace Engineer, Engine

Certification Office, FAA, Engine and

Propeller Directorate, 12 New England

Executive Park, Burlington, MA 01803–

5299; telephone: (781) 238–7740, fax:

(781) 238–7199.

SUPPLEMENTARY INFORMATION: A

proposal to amend part 39 of the Federal

Aviation Regulations (14 CFR part 39) to

include an AD that is applicable to

General Electric Co. (GE) CF6–80C2

turbofan engines with certain stage 1

HPT rotor disks installed was published

in the Federal Register on March 12,

2001 (66 FR 14348). That action

proposed to detect cracks in the bottoms

of the dovetail slots that could

propagate to failure of the disk and

cause an uncontained engine failure.

Comments

Interested persons have been afforded

an opportunity to participate in the

making of this amendment. Due

consideration has been given to the

comments received.

Include Alert Service Bulletin Revision 1

One commenter states that Table 1

should reference GE Alert Service

Bulletin (ASB) CF6–80C2 72–A1024,

Revision 1, dated November 3, 2000, as

well as the original ASB issue.

The FAA agrees. The inspection

requirements in ASB Revision 1 are the

equivalent of the inspection

requirements of original issue ASB CF6–

80C2 72–A1024, dated October 13,

2000. Reference to ASB CF6–80C2 72–

Federal Register / Vol. 66, No. 97 / Friday, May 18, 2001 / Rules and Regulations 27593

A1024, Revision 1 has been added to the

final rule.

Change Economic Impact To Reflect

Labor Cost for Engines That Are Not

Due for HPT Piece-Part Exposure

Three commenters request that the

economic impact include labor costs for

engines in the shop, that would

otherwise not require HPT piece-part

exposure. The commenters state that not

all engine shop visits (ESV’s) (scheduled

or unscheduled) require complete

disassembly of the HPT rotor. One

commenter states that their inventory

has 77 HPT rotor stage 1 disks that will

require the inspection proposed in the

rule over the next year, and an

additional 22 units that will require 24

hours of labor to complete piece-part

exposure of the HPT rotor that would

otherwise have remained assembled

during the shop visit. Another

commenter estimated it would cost an

additional $22,000 per year to complete

the additional disassembly required to

perform the inspections.

The FAA agrees. After considering the

information presented by commenters,

the FAA revised the subject work hours

in the labor cost impact information.

The FAA estimates that approximately

75% of all engines introduced into a

shop each year will have the HPT at

piece-part level. The remaining 25%

would require additional work scope to

obtain HPT rotor piece-part exposure.

The economic impact is revised to

include this additional cost.

Change Economic Impact To Reflect

Parts and Labor Costs Per Year, Due to

‘‘Check & Repair’’ Engines

One commenter requests that the

economic impact include parts and

labor costs per year, for ‘‘Check &

Repair’’ engines that would be upgraded

to heavy work scopes due to the ‘‘Next

Shop Visit’’ provision of the proposed

rule. The commenter states that engines,

termed as ‘‘Check & Repair’’ engines,

which is on-average eight engines per

year, would have to be upgraded to

heavy work scopes due to the ‘‘Next

Shop Visit’’ provision of the proposed

rule. The commenter states that this is

an additional $2,000,000 in parts and

labor costs per year. The commenter

does not provide a breakdown of the

total cost, but suggests that the

additional exemptions requested to the

definition of ESV would minimize the

exposure to ‘‘Check & Repair’’ increased

work scope.

The FAA partially agrees. The FAA’s

interpretation of a ‘‘Check and Repair’’

engine is one that is introduced into a

shop to address a known problem, with

a limited work scope. The commenter

did not provide the breakdown in the

stated cost for these engines. The FAA

has already included two exemptions to

the definition of ESV in the notice of

proposed rulemaking (NPRM) to lessen

the economic impact of these

maintenance actions. Any additional

exemptions would result in an

unacceptable level of safety. Therefore,

the FAA made no changes to the rule

with respect to this request. However,

the economic impact has been revised to

include the cost of the additional work

scope required by approximately 25% of

the engines affected by this AD, that

would not have completed HPT rotor

piece-part disassembly otherwise,

during their ESV.

Change Economic Impact To Include

Disk Replacement Cost

One commenter states that the

economic impact in the NPRM did not

include the $283,480 cost of a

replacement disk when a disk is found

unserviceable.

The FAA disagrees. The economic

impact section of the NPRM did, in fact,

include the cost of a replacement disk,

assuming an annual projected rate of

disks found unserviceable during the

inspection program.

Clarify Inspection Requirements for

Disks With Zero Cycles-Since-New

(CSN), at Time of Inspection Using GE

ASB CF6–80C2 72–A1024

One commenter requests that the

inspection requirements for disks with

zero CSN at the time of inspection and

using ASB CF6–80C2 72–A1024, be

clarified. The commenter states the

NPRM is unclear, but did not supply

any supporting data.

The FAA partially agrees. ASB CF6–

80C2 72–A1024 was issued as an

interim step for engines undergoing

HPT overhaul during the development

of, and prior to, the implementation of

the eddy current inspection (ECI), as

introduced in ASB CF6–80C2 72–

A1026. Since ASB CF6–80C2 72–A1024

was issued for shop use during HPT

overhaul, the FAA expects there are no

disks with zero CSN that were inspected

per ASB CF6–80C2 72-A1024. The FAA

does not consider it necessary to

identify disks with zero CSN, in

particular with respect to inspection in

accordance with ASB CF6–80C2 72–

A1024. However, to help clarify disk

inspection requirements, the FAA has

changed the inspection requirement of

Table 1, row three, to exclude

inspection of disks with zero CSN.

Furthermore, the intent of the

inspections in both ASB CF6–80C2 72–

A1024 and ASB CF6–80C2 72–A1026 is

to detect cracks in the bottoms of the

dovetail slots that have grown during

engine service. The propagation occurs

during accumulation of disk cycles.

Potential cracks have not propagated in

unused disks, therefore, inspections of

unused disks do not mitigate the risk.

Clarify Inspection Requirements for

Disks With Less Than 1,500 CSN

One commenter states that the NPRM

is unclear, and requests clarification of

the required inspection for a disk that

has less than 1,500 CSN on the effective

date of this AD, and is at piece-part

condition after the effective date of this

AD. The commenter speculates that the

average Mean Time Between Shop Visit

on the CF6–80C2 engine is less than

approximately 3,500 CSN, and in some

instances the Mean Time Between Shop

Visit is less than 1,000 cycles.

The FAA disagrees that clarification is

required. If an HPT stage 1 disk is at

piece-part condition, this qualifies as an

ESV according to the NPRM. Therefore,

the disk satisfies the requirements for

Table 1, paragraph 1, and must be

inspected. The initial inspection of all

disks is required to occur at the next

ESV. Also, paragraph (c) of this AD

clearly states that after the effective date

of this AD, stage 1 HPT rotor disks with

greater than zero CSN must not be

installed until inspected. If the disk has

1,500 or fewer CSN on the effective date

of this AD, this initial inspection must

occur at the next ESV, but before the

disk usage exceeds 5,000 CSN,

regardless of whether or not another

shop visit is anticipated before the disk

reaches 5,000 CSN. The proposed

compliance times of the rule considered

ESV rates, while maintaining an

acceptable level of safety. In

determining the calculated risk levels,

the engine shop visit cyclic distribution

data was used in the statistical model.

Add Contact Information for Reporting

Requirements

Two commenters request that contact

information such as telephone number,

fax number, address, and e-mail address

of the Engine Certification Manager be

added to the Reporting Requirements

Section of the final rule. The FAA

agrees. The contact information is added

to the final rule.

Change ‘‘Next Engine Shop Visit’’ to

‘‘Any Engine Shop Visit’’

One commenter requests that the

initial inspection be required at any

shop visit, not to exceed 3,500 cyclesin-service for used disks, and not to

exceed 5,000 CSN for new disks. No

substantiating data was included with

this comment. The reason for the

27594 Federal Register / Vol. 66, No. 97 / Friday, May 18, 2001 / Rules and Regulations

request was stated as airline operator

convenience.

The FAA disagrees. In determining

the calculated risk levels, the ESV cyclic

distribution data was used in the

statistical model. From a calculated risk

standpoint, specifying only cycles is not

the same as specifying next shop visit

not to exceed a certain number of

cycles. The initial inspection intervals

of next shop visit are based on the risk

assessment of the entire fleet. The

change requested by the commenter

would result in an extension of the

inspection intervals. Extensions to the

inspection intervals would increase

risks to an unacceptable level of safety.

Incorporate Additional Exemptions to

Engine Shop Visit

Four commenters request that

paragraph (d)(2) of the Compliance

section in the NPRM be changed to add

other maintenance actions as

exemptions to an ESV, to include the

following, individually and in

combination:

Introduction of an engine into a shop

solely for:

• Removal or replacement of the stage

1 fan disk.

• Replacement of the Turbine Rear

Frame.

• Replacement of the Accessory and/

or Transfer Gearboxes.

• Replacement of the fan forward

case.

One of the four commenters suggests

that these proposed exemptions are to

address quick turn-time maintenance

actions, and that these quick turn-time

maintenance actions would otherwise

not require HPT rotor piece-part

disassembly. Therefore, the commenter

suggests that significant additional cost

would result if the visits for these

maintenance actions were not exempt.

In addition, this commenter states that

their experience shows the number of

engines that fall into the proposed

categories are limited, and therefore, the

proposed exemptions for ESV’s will

have no significant detriment to the

level of safety over the program. All four

commenters recommend that the

addition of these exemptions will be

consistent with AD 99–24–15 (CF6 High

Pressure Compressor (HPC) stage 3–9

Spool Inspection). One of the four

commenters states that these ESV

exemptions will minimize the operator’s

exposure during ‘‘Check & Repair’’ work

scope shop visits.

The FAA disagrees that additional

ESV exemptions are appropriate for this

rule, based on the severity of the

potential unsafe condition. As one

commenter cited, the FAA finds that the

frequency of these proposed shop visit

exemptions is very low. While the four

commenters request consistency with

the existing AD 99–24–15 (HPC stage 3–

9 spool inspection), the FAA notes that

the most recent HPC stage 3–9 spool

inspection, AD 2000–16–12, contains no

exemptions from the definition of shop

visit. The NPRM allowed two

exemptions to the definition of an ESV,

while maintaining the necessary level of

safety. The FAA made no changes to the

rule. In addition, operators can submit

a request for an alternate method of

compliance or adjustment of the

compliance time that provides an

acceptable level of safety. The NPRM

definition paragraph (d) is now

paragraph (e) in this rule.

Incorporate an Additional Exemption in

the Definition of Engine Shop Visit

One commenter requests an

additional exemption in the definition

of ESV to include a maintenance action

that will result in removal of the

compressor stator lower case, without

need to separate any other major

flanges. The commenter has a single

engine scheduled for removal for the

HPC 3–9 spool inspection. During the

shop visit, removal of the compressor

stator lower case may arise to replace

bushings. The commenter developed an

approved method to remove the lower

case after reinstalling the top case while

the engine is in a horizontal position,

without separating any major flanges.

The FAA disagrees. This was the only

request of this kind. As the rule is

intended to cover the entire fleet, the

FAA does not want to revise the AD

based on one engine. For unique

situations, operators can submit a

request for an alternative method of

compliance or adjustment of the

compliance time that provides an

acceptable level of safety. Therefore, the

FAA made no changes to the rule.

Add a Row to Table 1 for Disks Already

Inspected Per GE ASB CF6–80C2 72–

A1026

One commenter requests that a row be

added to Table 1 for disks already

inspected in accordance with GE ASB

CF6–80C2 72–A1026 before the effective

date of this AD. The added row would

state a compliance time of ‘‘any number

of CSN if the disk has been inspected

using ASB CF6–80C2 72–A1026, dated

January 17, 2001, before the effective

date of this AD’’, with an initial

inspection that is ‘‘not applicable’’, and

a repetitive inspection that is ‘‘at each

piece-part exposure’’. The commenter

provides no substantiating data.

The FAA partially agrees. The FAA

has been informed that approximately

20 disks from US operators have been

inspected in accordance with ASB CF6–

80C2 72–A1026, dated January 17, 2001,

since that ASB’s issuance. These disks

have significant cycles-since-new, and

do not require another inspection until

next piece-part exposure. Therefore,

Table 1 remains as-written and a

paragraph has been added to the

compliance section stating that, for a

stage 1 HPT rotor disk that has been

inspected in accordance with 3.A(1)

through 3.C.(10)(i) of the

Accomplishment Instructions of GE

Alert Service Bulletin (ASB) CF6–80C2

72–A1026, dated January 17, 2001,

before the effective date of this AD, and

had greater than zero cycles-since-new

(CSN) at the time of inspection, inspect

the disk at each piece-part exposure,

and replace as necessary. In addition,

operators can submit a request for an

alternative method of compliance or

adjustment of the compliance time that

provides an acceptable level of safety.

Option To Perform Initial Inspection for

Zero Cycle Disks

One commenter requests an option to

perform ASB CF6–80C2 72–A1026,

dated January 17, 2001, for zero cycle

disks prior to installation. The

commenter does not provide technical

justification. The commenter states that

since GE does not offer an HPT stage 1

disk that is not affected by the proposed

AD, all first-run engines and engines in

which zero cycle disks are or will be

installed, will be limited to 5,000 CSN.

Because the inspections cannot be

performed on-wing or at engine-level,

the proposed rule will cause forcedengine removals and disassembly of the

HPT for short range applications.

The FAA disagrees. The intent of the

inspection is to detect cracks in the

bottoms of the dovetail slots that have

grown during engine cyclic service. The

propagation occurs during accumulation

of disk cycles. Potential cracks have not

propagated in unused disks, therefore,

inspections of unused disks do not

mitigate the risk. The greater the

number of cycles accumulated, the

greater the risk for fatigue-induced

failure. Therefore, short haul operators

or operators with fleets that accumulate

a large number of cycles per year are

more significantly at risk of disk failure.

Change Initial Inspection Threshold,

Paragraph 1, of Table 1, for Disks With

1,500 or Fewer CSN

One commenter requests a change in

Table 1, paragraph (1), for disks with

1,500 or fewer CSN on the effective date

of the AD, to change the initial

inspection threshold from ‘‘not to

exceed 5,000 CSN’’ to ‘‘not to exceed

5,000 CSN or 10,000 hours time-sinceVerDate 11<MAY>2000 15:04 May 17, 2001 Jkt 194001 PO 00000 Frm 00004 Fmt 4700 Sfmt 4700 E:\FR\FM\18MYR1.SGM pfrm01 PsN: 18MYR1
Federal Register / Vol. 66, No. 97 / Friday, May 18, 2001 / Rules and Regulations 27595

new, whichever comes later.’’ The

commenter provided no technical

substantiation. The commenter states

that since all HPT stage 1 disks are

affected by the proposed AD, and the

inspections cannot be performed onwing or at engine level, short range

applications will cause forced-engine

removals.

The FAA disagrees. Specifying hourssince-new does not address the cyclic

nature of the crack propagation. The

intent of the inspection is to detect

cracks in the bottoms of the dovetail

slots that have propagated during engine

cyclic service. Because the propagation

is related to low-cycle fatigue, the

propagation occurs during accumulation

of disk cycles. The greater the number

of cycles accumulated, the greater the

risk for fatigue-induced failure.

Therefore, short haul operators or

operators with fleets that accumulate a

large number of cycles per year are more

significantly at risk of disk failure.

Inspections according to the compliance

times in this rule will maintain an

acceptable level of safety. Therefore, the

FAA made no changes to the rule.

Review Initial Eddy Current Inspection

Data

Two commenters request that the

‘‘Next Shop Visit’’ accomplishment

schedule be reviewed by the FAA, GE,

and the airlines, after substantial data

has been collected from the initial eddy

current inspections. The commenters

note that each data point referenced in

the discussion of the proposed rule

refers to crack initiation due to handling

damage. The commenters believe a

timely review of the expanded data set

resulting from the inspection program is

necessary to confirm the proposed

schedule ensures safety without placing

an unwarranted burden on the

operators.

The FAA partially agrees. The FAA

considers this rule to be an interim

action. A timely review of the expanded

data set resulting from the inspection

program is appropriate. Additional

inspection results will be considered to

ensure that the actions and schedule

provide an acceptable level of safety.

While the rule requires that inspection

rejects be reported to the FAA, it is

recommended that operators comply

with GE’s request for all inspection

results be sent to GE, regardless of pass

or failure of the inspection. All data,

including successes and failures, will be

analyzed to evaluate the safety level,

and risk of a future event. The subject

of handling damage will be discussed in

the next response.

Initial Inspection Exemption for New

Disks Installed in Engines Since New

Two commenters request that the

hard time limits for initial inspections

in Table 1, items 1 and 2, should not

apply to new disks which have been

installed in engines since new. The

commenters reason that because new

disks have not been repaired or

handled, this should preclude the disks

from incurring the damage referenced in

the proposed rule.

The FAA disagrees. It is possible to

incur damage during any handling of

the disk, such as during part

manufacture, engine assembly, engine

disassembly, and during engine

overhaul. Recent data on a disk

previously rejected by an overhaul shop

for a fluorescent-penetrant inspection

indication at a slot end broaching burr

that had not been completely removed

at manufacturing, was destructively

evaluated. This burr was associated

with a crack, which extended into the

slot aft corner. The crack had not

propagated from fatigue. While this disk

did not have cracking in the slot bottom

corner, this finding suggests that it is

possible for a disk to have a

manufactured burr-related crack as a

potential root cause for this series of

events. Based on this data, the FAA

made no changes to the rule.

Change to Definition of Piece-Part

Exposure

The FAA has also changed the

definition of piece-part exposure in

paragraph (e) of the final rule. The

proposal provided that a piece-part

exposure would be achieved by a

complete disassembly performed in

accordance with the engine

manufacturer’s manual. It is possible

that some operators may disassemble

the HPT rotor disk using their own

manual. Therefore, to make clear that a

complete disassembly performed in

accordance with an FAA-approved

manual other than the manual

published by the engine manufacturer,

would constitute a piece-part exposure

of the HPT rotor disk, the FAA has

added the phrase ‘‘or other FAAapproved’’ to paragraph (e)(1)(i) of the

final rule.

After careful review of the available

data, including the comments noted

above, the FAA has determined that air

safety and the public interest require the

adoption of the rule with the changes

described previously. The FAA has

determined that these changes will

neither increase the economic burden

on any operator nor increase the scope

of the AD.

Economic Impact

There are approximately 2,954

engines of the affected design in the

worldwide fleet. The FAA estimates that

637 engines installed on aircraft of U.S.

registry will be affected by this AD. The

FAA estimates that it will take

approximately three work hours per

engine to accomplish the required

actions, and the average labor rate is $60

per work hour. Required parts will cost

approximately $283,480 per engine. The

FAA also estimates that approximately

191 engines per year will have shop

visits, and that of those 191 engines,

approximately two disks per year will

have to be replaced. Also, based on

information provided by NPRM

commenters to the FAA, approximately

48 (25%) of the shop visits will require

additional work scope because they

would not otherwise have required HPT

rotor piece-part disassembly. The FAA

estimates it will take approximately 50

work hours per engine to accomplish

the required additional work scope

actions, and the average labor rate is $60

per work hour. Based on these figures,

the total additional work scope labor

cost will be approximately $144,000.

Based on all of these figures, the total

cost impact of the proposed AD on U.S.

operators is estimated to be $745,340

per year.

Regulatory Impact

This final rule does not have

federalism implications, as defined in

Executive Order 13132, because it

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.

Accordingly, the FAA has not consulted

with state authorities prior to

publication of this final rule. For the

reasons discussed above, I certify that

this action (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) if promulgated, will

not have a significant economic impact,

positive or negative, on a substantial

number of small entities under the

criteria of the Regulatory Flexibility Act.

A final evaluation has been prepared for

this action and it is contained in the

Rules Docket. A copy of it may be

obtained by contacting the Rules Docket

at the location provided under the

caption ADDRESSES.

27596 Federal Register / Vol. 66, No. 97 / Friday, May 18, 2001 / Rules and Regulations

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation

safety, Incorporation by reference,

Safety.

Adoption of the Amendment

Accordingly, pursuant to the

authority delegated to me by the

Administrator, the Federal Aviation

Administration amends part 39 of the

Federal Aviation Regulations (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. Section 39.13 is amended by

adding a new airworthiness directive to

read as follows:

2001–10–07 General Electric Co.:

Amendment 39–12233. Docket No.

2001–NE–05–AD.

Applicability

This airworthiness directive (AD) is

applicable to General Electric Company (GE)

CF6–80C2 series turbofan engines with stage

1 high pressure turbine (HPT) rotor disks,

part numbers (P/N’s) 1531M84G02,

1531M84G06, 1531M84G08, 1531M84G10,

9392M23G10, 9392M23G12, 9392M23G21,

and 1862M23G01 installed. These engines

are installed on, but not limited to Airbus

Industrie A300 and A310 series, Boeing 747

and 767 series, and McDonnell Douglas MD–

11 series airplanes.

Note 1: This AD applies to each engine

identified in the preceding applicability

provision, regardless of whether it has been

modified, altered, or repaired in the area

subject to the requirements of this AD. For

engines that have been modified, altered, or

repaired so that the performance of the

requirements of this AD is affected, the

owner/operator must request approval for an

alternative method of compliance in

accordance with paragraph (g) of this AD.

The request should include an assessment of

the effect of the modification, alteration, or

repair on the unsafe condition addressed by

this AD; and, if the unsafe condition has not

been eliminated, the request should include

specific proposed actions to address it.

Compliance

Compliance with this AD is required as

indicated below, unless already done.

To detect cracks in the bottoms of the

dovetail slots that could propagate to failure

of the disk and cause an uncontained engine

failure, perform the following inspections:

(a) For stage 1 HPT rotor disks that have

been inspected prior to the effective date of

this AD, in accordance with 3.A(1) through

3.C.(10)(i) of the Accomplishment

Instructions of GE Alert Service Bulletin

(ASB) CF6–80C2 72–A1026, dated January

17, 2001, and had greater than zero cyclessince-new (CSN) at the time of inspection,

inspect the disk at each piece-part exposure,

and replace as necessary.

(b) For stage 1 HPT rotor disks not

previously inspected, inspect the disk in

accordance with 3.A.(1) through 3.C.(10)(i) of

the Accomplishment Instructions of GE ASB

CF6–80C2 72–A1026, dated January 17, 2001,

and Table 1 of this AD, and replace if

necessary, as follows:

TABLE 1.—COMPLIANCE TIMES FOR STAGE 1 HPT ROTOR DISK INSPECTIONS

Stage 1 HPT Rotor Disk Cycles-since-new

(CSN) on the effective date of this AD Initial inspection Repetitive inspections

(1) 1,500 CSN or fewer ..................................... At the next engine shop visit (ESV) after the

effective date of this AD, but not to exceed

5,000 CSN.

At each piece-part exposure.

(2) More than 1,500 CSN .................................. At the next ESV after the effective date of this

AD, but not to exceed 3,500 cycles-in-service (CIS) after the effective date of this AD.

At each piece-part exposure.

(3) Any number of CSN if the disk has been inspected using ASB CF6–80C2 72–A1024,

Revision 1, dated November 3, 2000, or

original ASB issue, dated October 13, 2000,

before the effective date of this AD, and, if

the disk had greater than zero CSN at the

time of inspection.

At the next ESV after the effective date of this

AD.

At each piece-part exposure.

(c) After the effective date of this AD, do

not install any stage 1 HPT rotor disk with

greater than zero CSN until it has been

inspected in accordance with 3.A.(1) through

3.C.(10)(i) of the Accomplishment

Instructions of GE ASB CF6–80C2 72–A1026,

dated January 17, 2001.

(d) Thereafter, inspect the disk at each

piece-part exposure, and replace if necessary.

Definitions

(e) The following definitions apply for this

AD:

(1) Piece-part exposure means the stage 1

HPT rotor disk is considered completely

disassembled as follows:

(i) When done in accordance with the

disassembly instructions in the engine

manufacturer’s, or other FAA-approved

engine manual, AND

(ii) The disk has accumulated more than

100 CIS since the last piece-part opportunity

inspection, if the disk was not damaged or

related to the cause for its removal from the

engine.

(2) An ESV is defined as the induction of

an engine into a shop where the separation

of a major engine flange will occur after the

effective date of this AD. The following

actions, either separately or in combination,

are not considered ESV’s for the purpose of

this AD:

(i) Induction of an engine into a shop

solely for removal of the upper compressor

stator case for airfoil maintenance.

(ii) Induction of an engine into a shop

solely for the module level inspection of the

high pressure compressor rotor 3–9 spool.

Reporting Requirements

(f) Report the results of inspections on all

disks that equal or exceed the reject criteria

of GE ASB CF6–80C2 72–A1026, dated

January 17, 2001, within 5 calendar days of

the inspection, to the Manager, Engine

Certification Office, FAA, Engine and

Propeller Directorate, 12 New England

Executive Park, Burlington, MA 01803–5299;

telephone: (781) 238–7140; fax: (781) 238–

7199. Reporting requirements have been

approved by the Office of Management and

Budget and assigned OMB control number

2120–0056. The following information must

be included in the report:

(1) Engine model in which the stage 1 HPT

rotor disk was installed, AND

(2) Disk P/N, AND

(3) Disk serial number, AND

(4) CSN on the disk, AND

(5) Cycles-since-last-inspection, AND

(6) Date and location of the inspection.

Alternative Methods of Compliance

(g) An alternative method of compliance or

adjustment of the compliance time that

provides an acceptable level of safety may be

used if approved by the Manager, Engine

Certification Office (ECO). Operators shall

submit their requests through an appropriate

FAA Principal Maintenance Inspector, who

may add comments and then send it to the

Manager, ECO.

Note 2: Information concerning the

existence of approved alternative methods of

Federal Register / Vol. 66, No. 97 / Friday, May 18, 2001 / Rules and Regulations 27597

compliance with this airworthiness directive,

if any, may be obtained from the ECO.

Special Flight Permits

(h) Special flight permits may be issued in

accordance with §§ 21.197 and 21.199 of the

Federal Aviation Regulations (14 CFR 21.197

and 21.199) to operate the aircraft to a

location where the requirements of this AD

can be accomplished.

Incorporation by Reference

(i) The inspections must be done in

accordance with GE ASB CF6–80C2 72–

A1026, dated January 17, 2001. This

incorporation by reference was approved by

the Director of the Federal Register in

accordance with 5 U.S.C. 552(a) and 1 CFR

part 51. Copies may be obtained 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. Copies

may be examined at the FAA, New England

Region, Office of the Regional Counsel, 12

New England Executive Park, Burlington,

MA, or at the Office of the Federal Register,

800 North Capitol Street, NW., suite 700,

Washington, DC.

Effective Date of This AD

(j) This amendment becomes effective on

June 18, 2001.

Issued in Burlington, Massachusetts, on

May 10, 2001.

Francis A. Favara,

Acting Manager, Engine and Propeller

Directorate, Aircraft Certification Service.

[FR Doc. 01–12374 Filed 5–17–01; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF THE TREASURY

Internal Revenue Service

26 CFR Part 48

[TD 8945]

RIN 1545–AY85

Taxable Fuel Measurement

AGENCY: Internal Revenue Service (IRS),

Treasury.

ACTION: Final regulations.

SUMMARY: This document contains final

regulations relating to the measurement

of taxable fuel. The regulations affect

certain blenders, enterers, refiners,

terminal operators, and throughputters.

DATES: Effective Date: These regulations

are effective May 18, 2001.

Applicability Date: These regulations

are applicable January 1, 1994.

FOR FURTHER INFORMATION CONTACT:

Frank Boland (202) 622–3130 (not a tollfree number).

SUPPLEMENTARY INFORMATION:

Background

Section 4081 imposes a tax on certain

removals, entries, and sales of taxable

fuel. Section 4083 provides that taxable

fuel means gasoline, diesel fuel, and

kerosene.

Before July 1, 2000, regulations

provided that gallons of taxable fuel

could be measured on the basis of actual

volumetric gallons or gallons adjusted to

60 degrees Fahrenheit. However,

regulations that were published in the

Federal Register on March 31, 2000,

(TD 8879; 65 FR 17149) provide that

beginning July 1, 2000, for each period

from July 1 through the following June

30 a person liable for tax on a removal

may use only one of the two bases of

measurement with respect to taxable

fuel removed from any particular

terminal, refinery, or blending facility.

This rule (the consistency requirement)

also applies to taxable entries and sales.

After publication of TD 8879, the IRS

and the Treasury Department

determined that many taxpayers would

have had to change their accounting

systems to comply with the consistency

requirement and would have been

unable to complete the necessary

changes by July 1, 2000. Accordingly,

Notice 2000–33 (2000–27 I.R.B. 97)

provided that taxpayers would not be

required to comply with the consistency

requirement before July 1, 2001. In the

meantime, a taxpayer could use either

basis of measurement for each taxable

removal, entry, or sale of taxable fuel.

Explanation of Provisions

The IRS and the Treasury Department

have now determined that the

consistency requirement would force

many taxpayers to alter current standard

business practices and potentially could

make routine IRS examinations more

time consuming and burdensome. To

avoid these adverse consequences, the

final regulations in this document

remove the consistency requirement and

reinstate the provision that was in effect

before July 1, 2000.

Effect on Other Documents

Notice 2000–33 (2000–27 I.R.B. 97) is

obsolete as of May 18, 2001.

Special Analyses

This rule relieves taxpayer burden by

eliminating a requirement with respect

to the measurement of taxable fuel.

Therefore, it has been determined that

notice and public comment are

unnecessary and contrary to the public

interest. For the same reason, a delayed

effective date under 5 U.S.C. 553(d) is

not required. Because no preceding

notice of proposed rulemaking is

required for this Treasury decision and

the rule does not impose on small

entities a collection of information

requirement, the provisions of the

Regulatory Flexibility Act do not apply.

It also has been determined that this

Treasury decision is not a significant

regulatory action as defined in

Executive Order 12866. Therefore, a

regulatory assessment is not required.

Pursuant to section 7805(f) of the Code,

these final regulations were submitted

to the Chief Counsel for Advocacy of the

Small Business Administration for

comment on their impact on small

business.

Drafting Information

The principal author of these

regulations is Frank Boland, Office of

Associate Chief Counsel (Passthroughs

and Special Industries). However, other

personnel from the IRS and Treasury

Department participated in their

development.

List of Subjects in 26 CFR Part 48

Excise taxes, Reporting and

recordkeeping requirements.

Adoption of Amendments to the

Regulations

Accordingly, 26 CFR part 48 is

amended as follows:

PART 48—MANUFACTURERS AND

RETAILERS EXCISE TAXES

Paragraph 1. The authority citation

for part 48 continues to read in part as

follows:

Authority: 26 U.S.C. 7805 * * *

Par. 2. Section 48.4081–8 is revised to

read as follows:

§ 48.4081–8 Taxable fuel; measurement.

(a) In general. Volumes of taxable fuel

may be measured on the basis of actual

volumetric gallons or gallons adjusted to

60 degrees Fahrenheit.

(b) Effective date. This section is

applicable January 1, 1994.

Approved: May 10, 2001.

Robert E. Wenzel,

Deputy Commissioner of Internal Revenue.

Mark A. Weinberger,

Assistant Secretary of the Treasury.

[FR Doc. 01–12600 Filed 5–17–01; 8:45 am]

BILLING CODE 4830–01–P