Federal Register / Vol. 65, No. 118 / Monday, June 19, 2000 / Rules and Regulations 37845

(ii) Accomplish paragraph (d) of this AD.

Note 3: 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.’’

Option 2: High Frequency Eddy Current and

Detailed Visual Inspections

(c) Remove the upper link and accomplish

the requirements of paragraphs (c)(1) and

(c)(2) of this AD, in accordance with Boeing

Service Bulletin 767–57–0053, Revision 2,

dated September 23, 1999.

(1) Perform a high frequency eddy current

inspection or a dye penetrant inspection to

detect cracking of the pitch load fittings of

the wing front spar.

(2) Perform a detailed visual inspection of

the inner and outer face pad-up areas of the

pitch load fittings to detect damage or

corrosion and to determine if the pad-up

areas are parallel. Except as provided by

paragraph (f) of this AD, if any damage,

corrosion, or non-parallelism is detected,

prior to further flight, rework the inner or

outer face of the pitch load fitting where

damage or corrosion was detected, and make

pad-up areas parallel, as applicable, in

accordance with the service bulletin.

Rework

(d) For airplanes on which any cracking is

detected during any inspection required by

paragraph (b) of this AD, or on which the

requirements of paragraph (c) of this AD have

been accomplished: Prior to further flight,

accomplish paragraph (d)(1) or (d)(2) of this

AD, as applicable, in accordance with Boeing

Service Bulletin 767–57–0053, Revision 2,

dated September 23, 1999; and accomplish

paragraph (e) of this AD.

(1) For airplanes inspected in accordance

with paragraph (c) of this AD and on which

no cracking was detected: Make an insurance

cut of the pitch load fitting lug.

(2) For airplanes on which any cracking

was detected during any inspection required

by paragraph (b) or (c) of this AD: Except as

provided by paragraph (f) of this AD, rework

the lugs of the pitch load fittings of the wing

front spar.

Bushing Installation

(e) For airplanes on which the

requirements specified in paragraph (d) of

this AD have been accomplished: Prior to

further flight, install new bushings in the

pitch load fittings of the wing front spar as

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

AD, in accordance with Boeing Service

Bulletin 767–57–0053, Revision 2, dated

September 23, 1999.

(1) Option 1: Install new bushings using

the high interference fit method, and repeat

the inspections required by paragraph (b) or

(c) of this AD at the intervals specified in

Table 1.3 of Figure 1. of the service bulletin.

(2) Option 2: Install new bushings using

the FORCEMATE method, and repeat the

inspections required by paragraph (b) or (c)

of this AD at the interval specified in Table

1.4 of Figure 1. of the service bulletin.

Repair

(f) If any damage is detected that is outside

the limits specified in Boeing Service

Bulletin 767–57–0053, Revision 2, dated

September 23, 1999, 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, Transport Airplane Directorate;

or in accordance with data meeting the type

certification basis of the airplane approved

by a Boeing Company Designated

Engineering Representative (DER) who has

been authorized by the Manager, Seattle

ACO, to make such findings. For a repair

method to be approved, as required by this

paragraph, the approval letter must

specifically reference this AD.

Optional Terminating Action

(g) Accomplishment of the actions

specified in paragraphs (g)(1) and (g)(2) of

this AD constitutes terminating action for the

actions required by this AD.

(1) Modify the nacelle strut and wing

structure in accordance with Boeing Service

Bulletin 767–54–0080, dated October 7, 1999

(for Model 767 series airplanes powered by

Pratt & Whitney engines); Boeing Service

Bulletin 767–54–0081, dated July 29, 1999

(for Model 767 series airplanes powered by

General Electric engines); or Boeing Service

Bulletin 767–54–0082, dated October 28,

1999 (for Model 767 series airplanes powered

by Rolls-Royce engines); as applicable.

(2) Accomplish the lug bore inspections

and insurance cut of the pitch load fitting in

accordance with Boeing Service Bulletin

767–57–0053, Revision 2, dated September

23, 1999.

Note 4: The FAA is considering separate

rulemaking actions to mandate

accomplishment of Boeing Service Bulletins

767–54–0080, 767–54–0081, and 767–54–

0082. Actions described in Boeing Service

Bulletin 767–57–0053, Revision 2 (or

previous issues of that service bulletin), as

required by this AD will be specified as an

integral part of the actions required to

accomplish these service bulletins.

Alternative Methods of Compliance

(h) 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 5: 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

(i) 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

(j) Except as provided in paragraphs (f) and

(g)(1) of this AD, the actions shall be done

in accordance with Boeing Service Bulletin

767–57–0053, Revision 2, dated September

23, 1999. 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 Boeing Commercial Airplane Group,

P.O. Box 3707, Seattle, Washington, 98124–

2207. Copies may be inspected at the FAA,

Transport Airplane Directorate, 1601 Lind

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

Office of the Federal Register, 800 North

Capitol Street, NW., suite 700, Washington,

DC.

Effective Date

(k) This amendment becomes effective on

July 24, 2000.

Issued in Renton, Washington, on June 9,

2000.

Donald L. Riggin,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 00–15183 Filed 6–16–00; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99–NM–351–AD; Amendment

39–11791; AD 2000–12–13]

RIN 2120–AA64

Airworthiness Directives; Airbus Model

A319, A320, and A321 Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule.

SUMMARY: This amendment supersedes

an existing airworthiness directive (AD),

applicable to certain Airbus Model

A319, A320, and A321 series airplanes,

that currently requires revising the

FAA-approved Airplane Flight Manual

(AFM) to increase monitoring of the

37846 Federal Register / Vol. 65, No. 118 / Monday, June 19, 2000 / Rules and Regulations

flight path of the airplane to detect

certain software anomalies of the flight

management guidance system, and take

appropriate corrective actions. This

amendment adds a requirement to either

modify the existing on-board

replaceable modules of the flight

management guidance computers

(FMGC) to incorporate software

changes, or replace the FMGC’s with

new, improved FMGC’s; which would

terminate the requirements for the AFM

revision. This amendment is prompted

by the issuance of mandatory

continuing airworthiness information by

a foreign civil airworthiness authority.

The actions specified by this AD are

intended to prevent erroneous

navigational calculations, which could

result in an increased risk of collision

with terrain or other airplanes.

DATES: Effective July 24, 2000.

The incorporation by reference of

certain publications listed in the

regulations is approved by the Director

of the Federal Register as of July 24,

2000.

The incorporation by reference of

certain other publications, as listed in

the regulations, was approved

previously by the Director of the Federal

Register as of November 3, 1997 (62 FR

53939, October 17, 1997).

ADDRESSES: The service information

referenced in this AD may be obtained

from Airbus Industrie, 1 Rond Point

Maurice Bellonte, 31707 Blagnac Cedex,

France. This information may be

examined at the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, Rules Docket,

1601 Lind Avenue, SW., Renton,

Washington; or at the Office of the

Federal Register, 800 North Capitol

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

FOR FURTHER INFORMATION CONTACT:

Norman B. Martenson, Manager,

International Branch, ANM–116, FAA,

Transport Airplane Directorate, 1601

Lind Avenue, SW., Renton, Washington

98055–4056; telephone (425) 227–2110;

fax (425) 227–1149.

SUPPLEMENTARY INFORMATION: A

proposal to amend part 39 of the Federal

Aviation Regulations (14 CFR part 39)

by superseding 97–21–10, amendment

39–10163 (62 FR 53939, October 17,

1997), which is applicable to certain

Airbus Model A319, A320, and A321

series airplanes, was published in the

Federal Register on April 14, 2000 (65

FR 20105). The action proposed to

continue to require a revision to the

Airplane Flight Manual (AFM) to

increase monitoring of the flight path of

the airplane to detect certain software

anomalies of the flight management

guidance system, and take appropriate

corrective actions. The action proposed

to add a requirement to either modify all

existing on-board replaceable modules

of the FMGC’s to incorporate software

changes, or replace all existing FMGC’s

with new, improved FMGC’s; which

would terminate the requirements for

the AFM revision. The action also

proposed to limit the applicability of the

existing AD to airplanes on which a

certain modification has been installed

or service bulletin has been

accomplished, and to exclude airplanes

on which another modification has been

installed or service bulletin has been

accomplished.

Interested persons have been afforded

an opportunity to participate in the

making of this amendment. Due

consideration has been given to the

comments received.

Support for the Proposal

One commenter, the manufacturer,

concurs with the content of the

proposal.

Later Revision of French Airworthiness

Directive

The same commenter states that

related French airworthiness directive

1999–411–140(B) has been revised to

Revision 1, dated May 3, 2000, to

include in the applicability Airbus

Model A319 and A320 series airplanes

having Airbus Modification 26717. The

commenter notes that the proposed AD

already includes these airplanes in its

applicability, but suggests that the AD

be revised to refer to the latest revision

of the French airworthiness directive.

The FAA concurs that Revision 1 of

the related French airworthiness

directive matches the applicability of

this AD and should be referenced for

completeness. Note 4 of the final rule

has been revised to include a reference

to Revision 1 of the French

airworthiness directive.

Conclusion

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 change

previously described. The FAA has

determined that this change will neither

increase the economic burden on any

operator nor increase the scope of the

AD.

Cost Impact

There are approximately 200

airplanes of U.S. registry that will be

affected by this AD.

The actions that are currently

required by AD 97–21–10 take

approximately 1 work hour per airplane

to accomplish, at an average labor rate

of $60 per work hour. Required parts

will be provided by the manufacturer at

no charge to the operators. Based on

these figures, the cost impact of the

previously required actions on U.S.

operators is estimated to be $60 per

airplane.

The new actions that are required by

this new AD will take approximately 1

work hour per airplane to accomplish,

at an average labor rate of $60 per work

hour. Based on these figures, the cost

impact of the new requirements of this

AD on U.S. operators is estimated to be

$12,000, or $60 per airplane.

The cost impact figures discussed

above are based on assumptions that no

operator has yet accomplished any of

the requirements of this AD action, and

that no operator would accomplish

those actions in the future if this AD

were not adopted.

Regulatory Impact

The regulations adopted herein will

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 final rule does not

have federalism implications under

Executive Order 13132.

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 DOT

Regulatory Policies and Procedures (44

FR 11034, February 26, 1979); and (3)

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 from the Rules

Docket at the location provided under

the caption ADDRESSES.

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:

Federal Register / Vol. 65, No. 118 / Monday, June 19, 2000 / Rules and Regulations 37847

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

removing amendment 39–10163 (62 FR

53939, October 17, 1997), and by adding

a new airworthiness directive (AD),

amendment 39–11791, to read as

follows:

2000–12–13 Airbus Industrie: Amendment

39–11791. Docket 99–NM–351–AD.

Supersedes AD 97–21–10, Amendment

39–10163.

Applicability: Model A319, A320, and

A321 series airplanes; certificated in any

category; on which any of the Airbus

modifications has been installed or any of the

Airbus service bulletins has been

accomplished, as listed in the following

table; except those airplanes on which Airbus

Modification 26716, 26799, 26968, or 27831

has been installed; or except those airplanes

on which Airbus Service Bulletin A320–22–

1063, A320–22–1064, A320–22–1065, A320–

22–1067, A320–22–1068, or A320–22–1069

has been accomplished:

Affected model(s) Airbus modification installed

A319 and A321 ............................... 25469 (reference Airbus Service Bulletin A320–22–1054).

A319, A320, and A321 ................... 26093.

A320 ................................................ 24065 (reference Airbus Service Bulletin A320–22–1040) or 24067 (reference Airbus Service Bulletin

A320–22–1039).

A320 ................................................ 25314 (reference Airbus Service Bulletin A320–22–1051) or 25315 (reference Airbus Service Bulletin

A320–22–1050).

A320 and A321 ............................... 24064 (reference Airbus Service Bulletin A320–22–1034) or 24066 (reference Airbus Service Bulletin

A320–22–1029).

A320 and A321 ............................... 25199 (reference Airbus Service Bulletin A320–22–1045) or 25200 (reference Airbus Service Bulletin

A320–22–1046).

A320 and A321 ............................... 25240 (reference Airbus Service Bulletin A320–22–1033) or 25274 (reference Airbus Service Bulletin

A320–22–1056).

A319, A320, and A321 ................... 26243.

A319 and A320 ............................... 26717.

Note 1: This AD applies to each airplane

identified in the preceding applicability

provision, regardless of whether it has been

otherwise 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 (e)(1) 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 erroneous navigational

calculations, which could result in an

increased risk of collision with terrain or

other airplanes, accomplish the following:

Restatement of Requirements of AD 97–21–

10

(a) Within 10 days after November 3, 1997

(the effective date of AD 97–21–10,

amendment 39–10163), revise the Normal

Procedures Section of the FAA-approved

Airplane Flight Manual (AFM) by inserting a

copy of Model A319/320/321 Flight Manual

Temporary Revision 4.03.00/02, dated May

28, 1997, into the AFM.

Note 2: When the temporary revision

specified in paragraph (a) of this AD has been

incorporated into the general revisions of the

AFM, the general revisions may be inserted

in the AFM, provided the information

contained in the general revisions is identical

to that specified in Model A319/320/321

Flight Manual Temporary Revision 4.03.00/

02.

New Requirements of this AD

(b) Within 18 months after the effective

date of this AD, accomplish either paragraph

(b)(1) or (b)(2) of this AD, in accordance with

Airbus Service Bulletin A320–22–1063,

Revision 01, dated October 8, 1999; A320–

22–1064, dated September 15, 1998; A320–

22–1065, dated October 28, 1998; A320–22–

1067, Revision 01, dated July 7, 1999; A320–

22–1068, dated December 9, 1998; or A320–

22–1069, dated February 1, 1999; as

applicable. Following accomplishment of

either paragraph (b)(1) or (b)(2) of this AD,

the AFM revision required by paragraph (a)

of this AD may be removed from the AFM.

(1) Modify all existing on-board

replaceable modules of the flight

management guidance computers (FMGC) to

incorporate software changes in accordance

with the Accomplishment Instructions of the

applicable service bulletin.

(2) Replace all existing FMGC’s with new,

improved FMGC’s in accordance with the

Accomplishment Instructions of the

applicable service bulletin.

(c) Accomplishment of either the

modification or replacement action required

by paragraph (b) of this AD constitutes

terminating action for the AFM requirements

of paragraph (a) of AD 98–19–08, amendment

39–10750. Following accomplishment of

either of those actions, remove the FAAapproved AFM revision required by that AD

(Airbus A319/320/321 Airplane Flight

Manual Temporary Revision 9.99.99/44,

Issue 2, dated March 3, 1998).

Spares

(d) As of the effective date of this AD, no

person shall install any FMGC part number

B546BAM0205, B546CAM0101,

B546BCM0204, B398BAM0207,

B398AAM0410, B546CCM0101,

B546CCM0102, B546CCM0103, or

B398BCM0107; unless it has been modified

in accordance with this AD.

Alternative Methods of Compliance

(e)(1) 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,

International Branch, ANM–116, FAA,

Transport Airplane Directorate. Operators

shall submit their requests through an

appropriate FAA Principal Maintenance

Inspector, who may add comments and then

send it to the Manager, International Branch,

ANM–116.

(2) Alternative methods of compliance,

approved previously in accordance with AD

97–21–10, amendment 39–10163, are

approved as alternative methods of

compliance with paragraph (a) of this AD.

Note 3: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the International Branch,

ANM–116.

Special Flight Permits

(f) 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

(g) The actions shall be done in accordance

with Model A319/320/321 Flight Manual

Temporary Revision 4.03.00/02, dated May

28, 1997; Airbus Service Bulletin A320–22–

1063, Revision 01, dated October 8, 1999;

Airbus Service Bulletin A320–22–1064,

dated September 15, 1998; Airbus Service

Bulletin A320–22–1065, dated October 28,

1998; Airbus Service Bulletin A320–22–1067,

Revision 01, dated July 7, 1999; Airbus

37848 Federal Register / Vol. 65, No. 118 / Monday, June 19, 2000 / Rules and Regulations

Service Bulletin A320–22–1068, dated

December 9, 1998; and Airbus Service

Bulletin A320–22–1069, dated February 1,

1999; as applicable.

(1) The incorporation by reference of

Airbus Service Bulletin A320–22–1063,

Revision 01, dated October 8, 1999; Airbus

Service Bulletin A320–22–1064, dated

September 15, 1998; Airbus Service Bulletin

A320–22–1065, dated October 28, 1998;

Airbus Service Bulletin A320–22–1067,

Revision 01, dated July 7, 1999; Airbus

Service Bulletin A320–22–1068, dated

December 9, 1998; and Airbus Service

Bulletin A320–22–1069, dated February 1,

1999; is approved by the Director of the

Federal Register in accordance with 5 U.S.C.

552(a) and 1 CFR part 51.

(2) The incorporation by reference of

Model A319/320/321 Flight Manual

Temporary Revision 4.03.00/02, dated May

28, 1997, was approved previously by the

Director of the Federal Register as of

November 3, 1997 (62 FR 53939, October 17,

1997).

(3) Copies may be obtained from Airbus

Industrie, 1 Rond Point Maurice Bellonte,

31707 Blagnac Cedex, France. Copies may be

inspected at the FAA, Transport Airplane

Directorate, 1601 Lind Avenue, SW., Renton,

Washington; or at the Office of the Federal

Register, 800 North Capitol Street, NW., suite

700, Washington, DC.

Note 4: The subject of this AD is addressed

in French airworthiness directive 1999–411–

140(B), dated October 20, 1999, and Revision

1, dated May 3, 2000.

(h) This amendment becomes effective on

July 24, 2000.

Issued in Renton, Washington, on June 9,

2000.

Donald L. Riggin,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 00–15182 Filed 6–16–00; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000–NM–78–AD; Amendment

39–11794; AD 2000–12–16]

RIN 2120–AA64

Airworthiness Directives; Boeing

Model 747 Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule; request for

comments.

SUMMARY: This amendment supersedes

an existing airworthiness directive (AD),

applicable to certain Boeing Model 747

series airplanes, that currently requires

repetitive inspections to detect fatigue

cracking or loose or missing fasteners of

the aft torque bulkheads of the outboard

nacelle struts; and repair, if necessary.

This amendment expands the

applicability of the existing AD to

include certain additional airplanes,

and removes certain other airplanes

from the applicability of the existing

AD. For all airplanes subject to this AD,

this amendment also requires

accomplishment of a new terminating

action. This action is necessary to

prevent fatigue cracking and loose or

missing fasteners in the aft torque

bulkheads of the outboard nacelle struts,

which could result in failure of an

outboard nacelle strut diagonal brace

load path and possible separation of the

nacelle from the wing. This action is

intended to address the identified

unsafe condition.

DATES: Effective July 5, 2000.

The incorporation by reference of

Boeing Alert Service Bulletin 747–

54A2184, Revision 1, dated May 6,

1999, as listed in the regulations, is

approved by the Director of the Federal

Register as of July 5, 2000.

The incorporation by reference of

Boeing Alert Service Bulletin 747–

54A2184, dated July 3, 1997, as listed in

the regulations, was approved

previously by the Director of the Federal

Register as of March 18, 1999 (64 FR

10205, March 3, 1999).

Comments for inclusion in the Rules

Docket must be received on or before

August 18, 2000.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 2000-NM–

78-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 also be sent

via the Internet using the following

address: 9-anm-iarcomment@faa.gov.

Comments sent via the Internet must

contain ‘‘Docket No. 2000–NM–78–AD’’

in the subject line and need not be

submitted in triplicate.

The service information referenced in

this AD 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; or at the Office of

the Federal Register, 800 North Capitol

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

FOR FURTHER INFORMATION CONTACT:

Tamara L. Anderson, Aerospace

Engineer, Airframe Branch, ANM–120S,

FAA, Transport Airplane Directorate,

Seattle Aircraft Certification Office,

1601 Lind Avenue, SW., Renton,

Washington 98055–4056; telephone

(425) 227–2771; fax (425) 227–1181.

SUPPLEMENTARY INFORMATION: On

February 22, 1999, the FAA issued AD

99–05–06, amendment 39–11054 (64 FR

10205, March 3, 1999), applicable to

certain Boeing Model 747 series

airplanes, to require repetitive

inspections to detect fatigue cracking or

loose or missing fasteners of the aft

torque bulkheads of the outboard

nacelle struts; and repair, if necessary.

That action was prompted by a report

indicating that cracking was found in

the aft torque bulkheads of the outboard

nacelle struts, and by the availability of

new service instructions for detecting

fatigue cracking that would not have

been detected by the required actions of

the existing AD. The requirements of

that AD are intended to detect and

correct such fatigue cracking and loose

or missing fasteners, which could result

in failure of an outboard nacelle strut

diagonal brace load path and possible

separation of the nacelle from the wing.

Explanation of Relevant Service

Information

Since the issuance of AD 99–05–06,

the FAA has reviewed and approved

Boeing Alert Service Bulletin 747–

54A2184, Revision 1, dated May 6,

1999. The alert service bulletin

describes procedures for repetitive

inspections to detect fatigue cracking or

loose or missing fasteners of the aft

torque bulkheads of the outboard

nacelle struts; and repair, if necessary.

These procedures are substantially

similar to those described in Boeing

Alert Service Bulletin 747–54A2184,

dated July 3, 1997, which was

referenced in AD 99–05–06 as an

appropriate source of service

information for accomplishment of

certain requirements of that AD.

However, Revision 1 of the alert service

bulletin adds new airplanes (Group 5)

that are subject to the repetitive

inspections (and repair, if necessary)

described in the original issue of the

alert service bulletin and required by

AD 99–05–06. For certain airplanes (i.e.,

the airplanes listed in Groups 1, 2, and

5 of the alert service bulletin), the alert

service bulletin also describes

procedures for a terminating action that

eliminates the need for the repetitive

inspections described in the alert

service bulletin for affected airplanes.

The terminating action involves

installation of doublers and fillers on

the forward side of the lower spar

fitting. Accomplishment of the actions

specified in the alert service bulletin is