60126 Federal Register / Vol. 65, No. 196 / Tuesday, October 10, 2000 / Proposed Rules

§ 39.13 [Amended]

2. Section 39.13 is amended by

adding the following new airworthiness

directive:

Boeing: Docket 2000–NM–157–AD.

Applicability: Model 767 series airplanes,

certificated in any category, as listed in

Boeing Service Bulletin 767–54A0101,

Revision 1, dated February 3, 2000.

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 (d) 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 fatigue cracking in primary

strut structure and reduced structural

integrity of the strut, which could result in

separation of the strut and engine,

accomplish the following:

Repetitive Inspections/Corrective Actions

(a) Before the accumulation of 10,000 total

flight cycles, or within 600 flight cycles after

the effective date of this AD, whichever

occurs later: Accomplish the inspections

required by paragraph (a)(1) or (a)(2) of this

AD, as applicable.

(1) Perform a detailed visual inspection of

the four aft-most fastener holes in the

horizontal tangs of the midspar fitting of the

strut to detect cracking, in accordance with

Part 1, ‘‘Detailed Visual Inspection,’’ of the

Accomplishment Instructions of Boeing

Service Bulletin 767–54A0101, Revision 1,

dated February 3, 2000. If no cracking is

detected, repeat the inspection thereafter at

the applicable intervals specified in Table 1,

‘‘Reinspection Intervals for Part 1—Detailed

Visual Inspection’’ included in Figure 1 of

the service bulletin.

Note 2: For the purposes of this AD, a

detailed visual inspection is defined as: ‘‘An

intensive visual examination of a specific

structural area, system, installation, or

assembly to detect damage, failure, or

irregularity. Available lighting is normally

supplemented with a direct source of good

lighting at intensity deemed appropriate by

the inspector. Inspection aids such as mirror,

magnifying lenses, etc., may be used. Surface

cleaning and elaborate access procedures

may be required.’’

(2) Perform a high frequency eddy current

inspection of the four aft-most fastener holes

in the horizontal tangs of the midspar fitting

of the strut to detect discrepancies (cracking,

incorrect fastener hole diameter), in

accordance with Part 2, ‘‘High Frequency

Eddy Current (HFEC) Inspection,’’ of the

Accomplishment Instructions of the service

bulletin. Accomplish the requirements

specified in paragraph (a)(2)(i) or (a)(2)(ii) of

this AD, as applicable; and repeat the

inspection thereafter at the applicable

intervals specified in Table 2, ‘‘Reinspection

Intervals for Part 2—HFEC Inspection’’

included in Figure 1 of the service bulletin.

(i) If no cracking is detected and the

fastener hole diameter is less than or equal

to 0.5322 inch, rework the hole in accordance

with Part 3 of the Accomplishment

Instructions of the service bulletin.

(ii) If no cracking is detected and the

fastener hole diameter is greater than 0.5322

inch, accomplish the requirements specified

in either paragraph (b)(1) or (b)(2) of this AD.

(b) If any cracking is detected after

accomplishment of any inspection required

by paragraph (a) of this AD, before further

flight, accomplish the requirements specified

in either paragraph (b)(1) or (b)(2) of this AD.

(1) Accomplish the terminating action

specified in Part 4 of the Accomplishment

Instructions of Boeing Service Bulletin 767–

54A0101, Revision 1, dated February 3, 2000.

Accomplishment of this paragraph

terminates the requirements of this AD.

(2) Replace the midspar fitting of the strut

with a serviceable part, or repair in

accordance with a method approved by the

Manager, Seattle Aircraft Certification Office

(ACO), FAA. Repeat the applicable

inspection thereafter at the applicable time

specified in paragraph (a)(1) or (a)(2) of this

AD.

(c) If any discrepancies (cracking, incorrect

fastener hole diameter) are detected after

accomplishment of any inspection required

by paragraph (a) of this AD, for which the

service bulletin specifies that the

manufacturer may be contacted for

disposition of those repair conditions: Before

further flight, accomplish the corrective

actions (including fastener hole rework and/

or midspar fitting replacement) in accordance

with a method approved by the Manager,

Seattle ACO; or in accordance with data

meeting the type certification basis of the

airplane approved by a Boeing Company

Designated Engineering Representative who

has been authorized by the Manager, Seattle

ACO, to make such findings.

Alternative Methods of Compliance

(d) 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, Seattle

ACO. Operators shall submit their requests

through an appropriate FAA Principal

Maintenance Inspector, who may add

comments and then send it to the Manager,

Seattle ACO.

Note 3: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Seattle ACO.

Special Flight Permit

(e) Special flight permits may be issued in

accordance with sections 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.

Issued in Renton, Washington, on October

3, 2000.

Donald L. Riggin,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 00–25968 Filed 10–6–00; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99–NM–127–AD]

RIN 2120–AA64

Airworthiness Directives; Boeing

Model 767 Series Airplanes Powered

by General Electric Engines

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes the

adoption of a new airworthiness

directive (AD) that is applicable to

certain Boeing Model 767 series

airplanes powered by General Electric

engines. This proposal would require

modification of the nacelle strut and

wing structure. This proposal is

prompted by reports indicating that the

actual operational loads applied to the

nacelle are higher than the analytical

loads that were used during the initial

design. Such an increase in loading can

lead to fatigue cracking in the primary

strut structure prior to an airplane

reaching its design service objective.

The actions specified by the proposed

AD are intended to prevent fatigue

cracking in the primary strut structure

and consequent reduced structural

integrity of the strut.

DATES: Comments must be received by

November 24, 2000.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 99–NM–

127–AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055–4056.

Comments may be inspected at this

location between 9:00 a.m. and 3:00

p.m., Monday through Friday, except

Federal holidays. Comments may be

submitted via fax to (425) 227–1232.

Comments may also be sent via the

Internet using the following address: 9-

anm–nprmcomment@faa.gov.

Comments sent via fax or the Internet

must contain ‘‘Docket No. 99–NM–127–

AD’’ in the subject line and need not be

submitted in triplicate. Comments sent

Federal Register / Vol. 65, No. 196 / Tuesday, October 10, 2000 / Proposed Rules 60127

via the Internet as attached electronic

files must be formatted in Microsoft

Word 97 for Windows or ASCII text.

The service information referenced in

the proposed rule may be obtained from

Boeing Commercial Airplane Group,

P.O. Box 3707, Seattle, Washington

98124–2207. This information may be

examined at the FAA, Transport

Airplane Directorate, 1601 Lind

Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

James G. Rehrl, Aerospace Engineer,

Airframe Branch, ANM–120S, FAA,

Seattle Aircraft Certification Office,

1601 Lind Avenue, SW., Renton,

Washington 98055–4056; telephone

(425) 227–2783; fax (425) 227–1181.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to

participate in the making of the

proposed rule by submitting such

written data, views, or arguments as

they may desire. Communications shall

identify the Rules Docket number and

be submitted in triplicate to the address

specified above. All communications

received on or before the closing date

for comments, specified above, will be

considered before taking action on the

proposed rule. The proposals contained

in this notice may be changed in light

of the comments received.

Comments are specifically invited on

the overall regulatory, economic,

environmental, and energy aspects of

the proposed rule. All comments

submitted will be available, both before

and after the closing date for comments,

in the Rules Docket for examination by

interested persons. A report

summarizing each FAA-public contact

concerned with the substance of this

proposal will be filed in the Rules

Docket.

Commenters wishing the FAA to

acknowledge receipt of their comments

submitted in response to this notice

must submit a self-addressed, stamped

postcard on which the following

statement is made: ‘‘Comments to

Docket Number 99–NM–127–AD.’’ The

postcard will be date stamped and

returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this

NPRM by submitting a request to the

FAA, Transport Airplane Directorate,

ANM–114, Attention: Rules Docket No.

99–NM–127–AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

The FAA has received reports

indicating that the airplane

manufacturer has accomplished a

structural reassessment of the damage

tolerance capabilities of the Boeing

Model 767 series airplane powered by

General Electric engines. This

reassessment indicates that the actual

operational loads applied to the nacelle

strut and wing structure are higher than

the analytical loads that were used

during the initial design. Subsequent

analysis and service history, which

includes numerous reports of fatigue

cracking on certain strut and wing

structure, indicate that fatigue cracking

can occur on the primary strut structure

before an airplane reaches its design

service objective of 20 years or 50,000

flight cycles. Analysis also indicates

that such cracking, if it were to occur,

would grow at a much greater rate than

originally expected. Fatigue cracking in

the primary strut structure would result

in reduced structural integrity of the

strut.

Explanation of Relevant Service

Information

Boeing recently has developed a

modification of the strut-to-wing

attachment structure installed on Model

767 series airplanes powered by General

Electric engines. This modification

significantly improves the load-carrying

capability and durability of the strut-towing attachments. Such improvements

also will substantially reduce the

possibility of fatigue cracking and

corrosion developing in the attachment

assembly.

The FAA has reviewed and approved

Boeing Service Bulletin 767–54–0081,

dated July 29, 1999, which describes

procedures for modification of the

nacelle strut and wing structure. The

modification consists of replacing many

of the significant load-bearing

components of the strut and wing (e.g.,

the side link fittings, the midspar

fittings, the side load fittings, certain

fuse pins assemblies, etc.) with

improved components.

The service bulletin contains a

formula for calculating an optional

compliance threshold for the specified

modification. This formula is intended

to be used as an alternative to the 20-

year calendar threshold specified in the

service bulletin.

In addition, Table 2 of the service

bulletin also identifies six related

service bulletin modifications that must

be accomplished before or at the same

time as the modification in Boeing

Service Bulletin 767–54–0081:

• Boeing Service Bulletin 767–29–

0057: The FAA has reviewed and

approved Boeing Service Bulletin 767–

29–0057, dated December 16, 1993,

which describes procedures for

modification of the electrical wiring

support of the alternating current motor

pump of the main hydraulic power

system. The modification involves

installing new band clamps and indexstraps, and on certain airplanes,

installing new wire support brackets on

the strut bulkhead.

• Boeing Service Bulletin 767–54–

0069: The FAA has reviewed and

approved Boeing Service Bulletin 767–

54–0069, Revision 1, dated January 29,

1998, which describes procedures for

rework of the side load fitting and

tension fasteners, as applicable, and

replacement of midspar fuse pins with

new, higher-strength midspar fuse pins.

The rework involves increasing the size

of the tension bolts of the inboard and

outboard side load fittings. The

replacement also involves installing

new, higher-strength bolts and radius

fillers in the side load fittings and

backup support structure, and installing

higher-strength fasteners common to the

front spar and rib number 8 rib post.

• Boeing Service Bulletin 767–54–

0083: The FAA has reviewed and

approved Boeing Service Bulletin 767–

54–0083, dated September 17, 1998,

which describes procedures for

replacement of the upper link with a

new, improved part that will increase

the strength and durability of the upper

link installation. That service bulletin

also describes procedures for

modification of the wire support bracket

attached to the upper link.

• Boeing Service Bulletin 767–54–

0088: The FAA has reviewed and

approved Boeing Service Bulletin 767–

54–0088, Revision 1, dated July 29,

1999, which describes procedures for

replacement of the upper link fuse pin

and aft pin with new, improved pins

that will increase the strength and

durability of the upper link installation.

• Boeing Service Bulletin 767–

54A0094: The FAA has previously

reviewed and approved Boeing Service

Bulletin 767–54A0094, Revision 1,

dated September 16, 1999. This service

bulletin is referenced as the appropriate

service information for accomplishing

the actions required in AD 2000–07–05,

amendment 39–11659, which was

issued March 31, 2000 (65 FR 18883,

April 10, 2000). This service bulletin

describes procedures for repetitive

detailed visual inspections to detect

cracking of the one-piece diagonal brace

of the forward and aft lugs, and

corrective actions, if necessary. The

corrective actions involve installing a

new, three-piece diagonal brace, which

eliminates the need for the repetitive

inspections. The service bulletin also

describes procedures for rework of the

three-piece diagonal brace, which

60128 Federal Register / Vol. 65, No. 196 / Tuesday, October 10, 2000 / Proposed Rules

increases the inspection intervals of the

three-piece diagonal brace.

• Boeing Service Bulletin 767–57–

0053: Boeing Service Bulletin 767–54–

0081 lists Boeing Service Bulletin 767–

57–0053, Revision 1, however, the FAA

has previously reviewed and approved

Boeing Service Bulletin 767–57–0053,

Revision 2, dated September 23, 1999.

This service bulletin is referenced as the

appropriate source of service

information for accomplishing the

actions required in AD 2000–12–17,

amendment 39–11795, which was

issued June 9, 2000 (65 FR 37843, June

19, 2000). Revision 1 also is acceptable

for compliance with the requirements in

that AD. Revision 2 of the service

bulletin describes procedures for

repetitive ultrasonic and eddy current

inspections of the pitch load fitting lugs

of the wing front spar for cracking, and

rework of the fitting, if necessary.

Accomplishment of the actions

specified in the service bulletins is

intended to adequately address the

identified unsafe condition.

Explanation of Requirements of

Proposed Rule

Since an unsafe condition has been

identified that is likely to exist or

develop on other products of this same

type design, the proposed AD would

require accomplishment of the actions

specified in the service bulletins

described previously, except as

discussed below.

Differences Between Proposed Rule and

Service Bulletin

Operators should note that, although

Boeing Service Bulletin 767–54–0081

specifies that the manufacturer may be

contacted for disposition of certain

damage conditions that may be detected

during accomplishment of the

modification, this proposal would

require the repair of those conditions to

be accomplished in accordance with a

method approved by the FAA.

Cost Impact

There are approximately 381

airplanes of the affected design in the

worldwide fleet. The FAA estimates that

159 airplanes of U.S. registry would be

affected by this proposed AD, that it

would take approximately 1,006 work

hours, including time for gaining access

and closing up, per airplane to

accomplish the proposed modification

in Boeing Service Bulletin 767–54–

0081, and that the average labor rate is

$60 per work hour. Based on these

figures, the cost impact of the proposed

AD on U.S. operators is estimated to be

$9,597,240, or $60,360 per airplane.

It would take approximately 16 work

hours per airplane to accomplish the

proposed actions described in Boeing

Service Bulletin 767–29–0057, at an

average labor rate of $60 per work hour.

Required parts would be provided at no

cost by the airplane manufacturer.

Based on these figures, the cost impact

of these proposed actions on U.S.

operators is estimated to be $152,640, or

$960 per airplane.

It would take approximately 106 work

hours per airplane to accomplish the

actions described in Boeing Service

Bulletin 767–53–0069, Revision 1, at an

average labor rate of $60 per work hour.

Required parts would be provided at no

cost by the airplane manufacturer.

Based on these figures, the cost impact

of these proposed actions on U.S.

operators is estimated to be $1,011,240,

or $6,360 per airplane.

It would take approximately 1 work

hour per airplane to accomplish the

actions described in Boeing Service

Bulletin 767–54–0083, at an average

labor rate of $60 per work hour.

Required parts would be provided at no

cost by the airplane manufacturer.

Based on these figures, the cost impact

of these proposed actions on U.S.

operators is estimated to be $9,540, or

$60 per airplane.

It would take approximately 4 work

hours per airplane to accomplish the

actions described in Boeing Service

Bulletin 767–54–0088, Revision 1, at an

average labor rate of $60 per work hour.

Required parts would be provided at no

cost by the airplane manufacturer.

Based on these figures, the cost impact

of these proposed actions on U.S.

operators is estimated to be $38,160, or

$240 per airplane.

It would take approximately 20 work

hours per airplane to accomplish the

proposed actions described in Boeing

Service Bulletin 767–54A0094, Revision

1, at an average labor rate of $60 per

work hour. Required parts would be

provided at no cost by the airplane

manufacturer. Based on these figures,

the cost impact of these proposed

actions on U.S. operators is estimated to

be $190,800, or $1,200 per airplane.

Because the actions described in this

service bulletin are already required by

another AD action, this proposed

requirement would add no new costs for

affected operators.

It would take approximately 5 work

hours per airplane to accomplish the

proposed actions described in Boeing

Service Bulletin 767–57–0053, Revision

2, at an average labor rate of $60 per

work hour. Based on these figures, the

cost impact of these proposed actions on

U.S. operators is estimated to be

$47,700, or $300 per airplane. Because

the actions described in this service

bulletin are already required by another

AD action, this proposed requirement

would add no new costs for affected

operators.

Some operators may have

accomplished certain modifications on

some or all of the airplanes in their

fleets, while other operators may not

have accomplished any of the

modifications on any of the airplanes in

their fleets. As indicated earlier in this

preamble, the FAA invites comments

specifically on the overall economic

aspects of this proposed rule.

The cost impact figures discussed

above are based on assumptions that no

operator has yet accomplished any of

the current or proposed requirements of

this AD action, and that no operator

would accomplish those actions in the

future if this AD were not adopted. The

cost impact figures discussed in AD

rulemaking actions represent only the

time necessary to perform the specific

actions actually required by the AD.

These figures typically do not include

incidental costs, such as the time

required to gain access and close up,

planning time, or time necessitated by

other administrative actions.

Regulatory Impact

The regulations proposed herein

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. Therefore,

it is determined that this proposal

would not have federalism implications

under Executive Order 13132.

For the reasons discussed above, I

certify that this 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) 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 copy of the draft

regulatory evaluation prepared for this

action 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.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation

safety, Safety.

The Proposed Amendment

Accordingly, pursuant to the

authority delegated to me by the

Federal Register / Vol. 65, No. 196 / Tuesday, October 10, 2000 / Proposed Rules 60129

Administrator, the Federal Aviation

Administration proposes to amend 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 the following new airworthiness

directive:

Boeing: Docket 99–NM–127–AD.

Applicability: Model 767 series airplanes

powered by General Electric engines, line

numbers 1 through 663 inclusive, certificated

in any category.

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 (d) 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 fatigue cracking in the primary

strut structure and consequent reduced

structural integrity of the strut, accomplish

the following:

Modification

(a) Modify the nacelle strut and wing

structure on both the left and right sides of

the airplane, in accordance with Boeing

Service Bulletin 767–54–0081, dated July 29,

1999, at the later of the times specified in

paragraphs (a)(1) and (a)(2) of this AD.

(1) Prior to the accumulation of 37,500

total flight cycles, or within 20 years since

date of manufacture, whichever occurs first.

Use of the optional threshold formula

described in Figure 1 on page 54 of the

service bulletin is an acceptable alternative to

the 20-year threshold provided that the

conditions specified in Figure 1 of the service

bulletin are met.

(2) Within 3,000 flight cycles after the

effective date of this AD.

(b) Prior to or concurrently with the

accomplishment of the modification of the

nacelle strut and wing structure required by

paragraph (a) of this AD; as specified in

paragraph 1.D., Table 2, ‘‘Prior or Concurrent

Service Bulletins,’’ on page 8 of Boeing

Service Bulletin 767–54–0081, dated July 29,

1999; accomplish the actions specified in

Boeing Service Bulletin 767–29–0057, dated

December 16, 1993; Boeing Service Bulletin

767–54–0069, Revision 1, dated January 29,

1998; Boeing Service Bulletin 767–54–0083,

dated September 17, 1998; Boeing Service

Bulletin 767–54–0088, Revision 1, dated July

29, 1999; Boeing Service Bulletin 767–

54A0094, Revision 1, dated September 16,

1999; and Boeing Service Bulletin 767–57–

0053, Revision 2, dated September 23, 1999;

as applicable, in accordance with those

service bulletins.

Note 2: AD 2000–12–17, amendment 39–

11795, requires accomplishment of Boeing

Service Bulletin 767–57–0053, Revision 2,

dated September 23, 1999. However,

inspections and rework accomplished in

accordance with Boeing Service Bulletin

767–57–0053, Revision 1, dated October 31,

1996, are acceptable for compliance with the

applicable actions required by paragraph (b)

of this AD.

Note 3: AD 2000–07–05, amendment 39–

11659, requires accomplishment of Boeing

Service Bulletin 767–54A0094, dated May

22, 1998. However, inspections and rework

accomplished in accordance with Boeing

Service Bulletin 767–54A0094, dated May

22, 1998, are acceptable for compliance with

the applicable actions required by paragraph

(b) of this AD.

(c) If any damage to the airplane structure

is found during the accomplishment of the

modification required by paragraph (a) of this

AD, and the service bulletin specifies to

contact Boeing for appropriate action: Prior

to further flight, repair in accordance with a

method approved by the Manager, Seattle

Aircraft Certification Office (ACO), FAA, or

a Boeing Company Designated Engineering

Representative who has been authorized by

the FAA to make such findings. For a repair

method to be approved by the Manager,

Seattle ACO, as required by this paragraph,

the Manager’s approval letter must

specifically reference this AD.

Alternative Methods of Compliance

(d) 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, Seattle

ACO. Operators shall submit their requests

through an appropriate FAA Principal

Maintenance Inspector, who may add

comments and then send it to the Manager,

Seattle ACO.

Note 4: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Seattle ACO.

Special Flight Permits

(e) Special flight permits may be issued in

accordance with sections 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.

Issued in Renton, Washington, on October

3, 2000.

Donald L. Riggin,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 00–25967 Filed 10–6–00; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000–NM–184–AD]

RIN 2120–AA64

Airworthiness Directives; Boeing

Model 757–200 Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes the

supersedure of an existing airworthiness

directive (AD), applicable to certain

Boeing Model 757–200 series airplanes,

that currently requires inspections to

detect cracking on the free edge of the

tang, if necessary, and of the fastener

holes in the lower spar chord; and

various follow-on actions. That AD also

provides for an optional terminating

action for the repetitive inspections.

This action would add inspections to

detect additional cracking of the

fastener holes in the lower spar chord.

This action also adds an optional

terminating modification. This proposal

is prompted by the issuance of new

service information. The actions

specified by the proposed AD are

intended to detect and correct fatigue

cracking in the lower spar chord, which

could result in reduced structural

integrity of the engine strut.

DATES: Comments must be received by

November 24, 2000.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 2000–NM–

184–AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055–4056.

Comments may be inspected at this

location between 9:00 a.m. and 3:00

p.m., Monday through Friday, except

Federal holidays. Comments may be

submitted via fax to (425) 227–1232.

Comments may also be sent via the

Internet using the following address: 9–

anm–nprmcomment@faa.gov.

Comments sent via fax or the Internet

must contain ‘‘Docket No. 2000–NM–

184–AD’’ in the subject line and need

not be submitted in triplicate.

Comments sent via the Internet as

attached electronic files must be

formatted in Microsoft Word 97 for

Windows or ASCII text.

The service information referenced in

the proposed rule may be obtained from

Boeing Commercial Airplane Group,

P.O. Box 3707, Seattle, Washington