47252 Federal Register / Vol. 65, No. 149 / Wednesday, August 2, 2000 / Rules and Regulations

Document No. Pages Revision Date

Total pages: 13

CFM56–2B

SB No. 73–074 ................................................................................................................. 1–13 1 January 12, 1998.

Total pages: 13

CFM56–3/3B/3C

SB No. 73–125 ................................................................................................................. 1–13 1 January 7, 1998.

Total pages: 13

CFM56–5

SB No. 73–135 ................................................................................................................. 1–13 1 January 7, 1998.

Total pages: 13

CFM56–5B

SB No. 73–055 ................................................................................................................. 1–13 1 January 7, 1998.

Total pages: 13

CFM56–5C

SB No. 73–070 ................................................................................................................. 1–13 1 January 7, 1998.

Total pages: 13

The incorporations by reference were

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 CFM International, Technical

Publications Department, 1 Neumann Way,

Cincinnati, OH 45215; telephone: (513) 552–

2800, fax: (513) 552–2816. Copies may be

inspected at the FAA, New England Region,

Office of the Regional Counsel, 12 New

England Executive Park, Burlington, MA

01803–5299; or at the Office of the Federal

Register, 800 North Capitol Street, NW., suite

700, Washington, DC.

Effective Date

(i) This amendment becomes effective on

October 2, 2000.

Issued in Burlington, Massachusetts on

July 14, 2000.

David A. Downey,

Assistant Manager, Engine and Propeller

Directorate, Aircraft Certification Service.

[FR Doc. 00–18523 Filed 8–1–00; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99–NM–79–AD; Amendment

39–11833; AD 2000–15–04]

RIN 2120–AA64

Airworthiness Directives; Boeing

Model 747–200 and –300 Series

Airplanes Equipped with General

Electric CF6–80C2 Series Engines

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule.

SUMMARY: This amendment supersedes

an existing airworthiness directive (AD),

applicable to certain Boeing Model 747–

200 and –300 series airplanes, that

currently requires various inspections

and functional tests to detect

discrepancies of the thrust reverser

control and indication system, and

correction of any discrepancy found.

This amendment requires installation of

a terminating modification, and

repetitive functional tests of that

installation, and repair, if necessary.

This amendment is prompted by the

results of a safety review of the thrust

reverser systems on Model 747 series

airplanes. The actions specified by this

AD are intended to ensure the integrity

of the fail safe features of the thrust

reverser system by preventing possible

failure modes in the thrust reverser

control system that can result in

inadvertent deployment of a thrust

reverser during flight.

DATES: Effective September 6, 2000.

The incorporation by reference of

certain publications listed in the

regulations is approved by the Director

of the Federal Register as of September

6, 2000.

The incorporation by reference of

Boeing Service Bulletin 747–78A2166,

Revision 1, dated October 9, 1997, as

listed in the regulations, was approved

previously by the Director of the Federal

Register as of August 25, 1999 (64 FR

39003, July 21, 1999).

The incorporation by reference of

Boeing Alert Service Bulletin 747–

78A2130, dated May 26, 1994, as listed

in the regulations, was approved

previously by the Director of the Federal

Register as of April 13, 1995 (60 FR

13623, March 14, 1995).

ADDRESSES: 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

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:

Larry Reising, Aerospace Engineer,

Propulsion Branch, ANM–140S, FAA,

Transport Airplane Directorate, Seattle

Aircraft Certification Office, 1601 Lind

Avenue, SW., Renton, Washington

98055–4056; telephone (425) 227–2683;

fax (425) 227–1181.

SUPPLEMENTARY INFORMATION: A

proposal to amend part 39 of the Federal

Aviation Regulations (14 CFR part 39)

by superseding AD 99–15–08,

amendment 39–11227 (64 FR 39003,

July 21, 1999), which is applicable to

certain Boeing Model 747–200 and -300

series airplanes, was published in the

Federal Register on December 28, 1999

(64 FR 72575). The action proposed to

continue to require various inspections

and functional tests to detect

discrepancies of the thrust reverser

control and indication system and

correction of any discrepancy found,

and installation of a terminating

modification, repetitive functional tests

of that installation, and repair, if

necessary.

Comments

Interested persons have been afforded

an opportunity to participate in the

making of this amendment. Due

consideration has been given to the

comment received.

Request to Remove Running Torque

Check From Functional Test

Procedures

One commenter, the airplane

manufacturer, requests that the running

torque check of the thrust reverser

system be removed from the functional

test procedures contained in Appendix

1 of the proposed rule. The commenter

states no justification for its request.

The FAA concurs with the

commenter’s request. The FAA finds

that the running torque check of the

Federal Register / Vol. 65, No. 149 / Wednesday, August 2, 2000 / Rules and Regulations 47253

thrust reverser system is not directly

related to the integrity of the cone brake

or the actuation system lock. The

running torque check is used to

determine whether the thrust reverser is

able to translate smoothly when

commanded to deploy or stow. This

check is described in Boeing 747

Airplane Maintenance Manual 78–31–

00 ‘‘Thrust Reverser System—

Adjustment/Test’’ and is performed

when the angle gearbox and ballscrew

actuator, the rotary flexible drive shaft,

or the center drive unit is replaced. The

FAA recognizes that it is appropriate to

perform the running torque check when

these components are replaced and

finds that it is not necessary to perform

this check as part of the functional test

specified in Appendix 1. Therefore, the

running torque check of the thrust

reverser system has not been included

in Appendix 1 of this final rule.

Conclusion

After careful review of the available

data, including the comment noted

above, the FAA has determined that air

safety and the public interest require the

adoption of the rule with the change

previously described. This change will

neither increase the economic burden

on any operator nor increase the scope

of the AD.

Cost Impact

There are approximately 9 Model

747–200 and –300 series airplanes of the

affected design in the worldwide fleet.

The FAA estimates that 2 airplanes of

U.S. registry will be affected by this AD.

The actions originally required by AD

95–06–01, and retained in this AD, take

approximately 33 work hours per

airplane to accomplish, at an average

labor rate of $60 per work hour. Based

on these figures, the cost impact of the

currently required actions on U.S.

operators is estimated to be $3,960, or

$1,980 per airplane, per inspection/test

cycle.

The other actions (repeating the

functional test of the cone brake

required by AD 95–06–01 at reduced

intervals) that are currently required by

AD 99–15–08, and retained in this AD,

do not add any additional economic

burden on affected operators.

The bracket installation required by

this new AD takes approximately 64

work hours per airplane to accomplish,

at an average labor rate of $60 per work

hour. Required parts will be provided

by the manufacturer at no cost to the

operators. Based on these figures, the

cost impact of the bracket installation

required by this AD on U.S. operators is

estimated to be $7,680, or $3,840 per

airplane.

The actuation system lock installation

required by this new AD takes

approximately 16 work hours per

airplane to accomplish, at an average

labor rate of $60 per work hour.

Required parts will be provided by the

manufacturer at no cost to the operators.

Based on these figures, the cost impact

of the lock installation required by this

AD on U.S. operators is estimated to be

$1,920, or $960 per airplane.

The functional test required by this

new AD takes approximately 2 work

hours per airplane to accomplish, at an

average labor rate of $60 per work hour.

Based on these figures, the cost impact

of the functional test required by this

AD on U.S. operators is estimated to be

$240, or $120 per airplane, per test

cycle.

The wiring modifications required by

this new AD take approximately 833

work hours per airplane to accomplish,

at an average labor rate of $60 per work

hour. Required parts will be provided

by the manufacturer at no cost to the

operators. Based on these figures, the

cost impact of these modifications

required by this AD on U.S. operators is

estimated to be $99,960, or $49,980 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:

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 39–11227 (64 FR

39003, July 21, 1999), and by adding a

new airworthiness directive (AD),

amendment 39–11833, to read as

follows:

2000–15–04 Boeing: Amendment 39–11833.

Docket 99-NM–79–AD. Supersedes AD

99–15–08, Amendment 39–11227.

Applicability: Model 747–200 and –300

series airplanes equipped with General

Electric Model CF6–80C2 series engines with

Power Management Control engine controls,

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 (h)(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 ensure the integrity of the fail safe

features of the thrust reverser system by

preventing possible failure modes in the

thrust reverser control system that can result

in inadvertent deployment of a thrust

reverser during flight, accomplish the

following:

RESTATEMENT OF THE ORIGINAL

REQUIREMENTS OF AD 95–06–01:

Repetitive Tests and Inspections

(a) Within 90 days after April 13, 1995 (the

effective date of AD 95–06–01, amendment

39–9171), perform tests of the position

switch module and the cone brake of the

center drive unit (CDU) on each thrust

reverser, and perform an inspection to detect

47254 Federal Register / Vol. 65, No. 149 / Wednesday, August 2, 2000 / Rules and Regulations

damage to the bullnose seal on the translating

sleeve on each thrust reverser, in accordance

with paragraphs III.A. through III.C. of the

Accomplishment Instructions of Boeing Alert

Service Bulletin 747–78A2130, dated May

26, 1994. Repeat the tests and inspection

thereafter at intervals not to exceed 1,000

hours time-in-service until the functional test

required by paragraph (d) of this AD is

accomplished.

(b) Within 9 months after April 13, 1995,

perform inspections and functional tests of

the thrust reverser control and indication

system in accordance with paragraphs III.D.

through III.F., III.H., and III.I. of the

Accomplishment Instructions of Boeing Alert

Service Bulletin 747–78A2130, dated May

26, 1994. Repeat these inspections and

functional tests thereafter at intervals not to

exceed 18 months.

Corrective Action

(c) If any of the inspections and/or

functional tests required by paragraphs (a)

and (b) of this AD cannot be successfully

performed, or if any discrepancy is found

during those inspections and/or functional

tests, accomplish either paragraph (c)(1) or

(c)(2) of this AD.

(1) Prior to further flight, correct the

discrepancy found, in accordance with

Boeing Alert Service Bulletin 747–78A2130,

dated May 26, 1994. Or

(2) The airplane may be operated in

accordance with the provisions and

limitations specified in an operator’s FAAapproved Minimum Equipment List (MEL),

provided that no more than one thrust

reverser on the airplane is inoperative.

RESTATEMENT OF REQUIREMENTS OF

AD 99–15–08:

Repetitive Tests/Terminating Action

(d) Within 1,000 hours time-in-service after

the most recent test of the CDU cone brake

performed in accordance with paragraph (a)

of this AD, or within 650 hours time-inservice after August 25, 1999 (the effective

date of AD 99–15–08, amendment 39–11227),

whichever occurs first: Perform a functional

test to detect discrepancies of the CDU cone

brake on each thrust reverser, in accordance

with Boeing Service Bulletin 747–78A2166,

Revision 1, dated October 9, 1997, or

paragraph III.B. of the Accomplishment

Instructions of Boeing Alert Service Bulletin

747–78A2130, dated May 26, 1994. Repeat

the functional test thereafter at the interval

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

AD, as applicable. Accomplishment of such

functional test constitutes terminating action

for the repetitive test of the CDU cone brake

required by paragraph (a) of this AD; the

position switch module tests and the

bullnose seal inspections continue to be

required as specified in paragraph (a) of this

AD.

(1) For airplanes equipped with thrust

reversers NOT modified in accordance with

Boeing Service Bulletin 747–78–2144,

Revision 1, dated April 11, 1996: Repeat the

functional test at intervals not to exceed 650

hours time-in-service.

(2) For airplanes equipped with thrust

reversers modified in accordance with

Boeing Service Bulletin 747–78–2144,

Revision 1, dated April 11, 1996: Repeat the

functional test at intervals not to exceed

1,000 hours time-in-service.

Corrective Action

(e) If any functional test required by

paragraph (d) of this AD cannot be

successfully performed, or if any discrepancy

is found during any functional test required

by paragraph (d) of this AD, accomplish

either paragraph (e)(1) or (e)(2) of this AD.

(1) Prior to further flight, correct the

discrepancy found, in accordance with

Boeing Service Bulletin 747–78A2166,

Revision 1, dated October 9, 1997, or

paragraph III.B. of the Accomplishment

Instructions of Boeing Alert Service Bulletin

747–78A2130, dated May 26, 1994. Or

(2) The airplane may be operated in

accordance with the provisions and

limitations specified in the operator’s FAAapproved MEL, provided that no more than

one thrust reverser on the airplane is

inoperative.

NEW REQUIREMENTS OF THIS AD:

Terminating Action

(f) Accomplish the requirements of

paragraphs (f)(1) and (f)(2) of this AD at the

times specified in those paragraphs.

Accomplishment of the actions required by

paragraph (f)(1) of this AD constitutes

terminating action for the requirements of

paragraphs (a), (b), (d), and (e) of this AD.

(1) Within 36 months after the effective

date of this AD, accomplish the requirements

of paragraphs (f)(1)(i) and (f)(1)(ii) of this AD.

(i) Install an actuation system lock bracket

and fastening hardware to each thrust

reverser in accordance with the

Accomplishment Instructions of Lockheed

Martin Service Bulletin 78–1007, Revision 1,

dated March 18, 1997, or Middle River

Aircraft Systems Service Bulletin 78–1007,

Revision 2, dated March 10, 1998.

(ii) Install an actuation system lock (also

called an electro-mechanical lock or electromechanical brake) on each thrust reverser in

accordance with the Accomplishment

Instructions of Lockheed Martin Service

Bulletin 78–1020, Revision 2, dated March

20, 1997, or Middle River Aircraft Systems

Service Bulletin 78–1020, Revision 3, dated

March 16, 1998.

(2) Prior to or concurrent with the

accomplishment of the requirements of

paragraph (f)(1)(ii) of this AD, perform the

thrust reverser wiring modifications of the

wings, strut, and fuselage, in accordance with

the Accomplishment Instructions of Boeing

Service Bulletin 747–78–2144, Revision 1,

dated April 11, 1996.

Repetitive Tests

(g) Within 1,000 hours time-in-service after

accomplishment of paragraph (f) of this AD,

or within 1,000 hours time-in-service after

the effective date of this AD, whichever

occurs later: Perform a functional test to

detect discrepancies of the CDU cone brake

and actuation system lock on each thrust

reverser, in accordance with Appendix 1 of

this AD. Prior to further flight, correct any

discrepancy detected and repeat the

functional test of that repair, in accordance

with the procedures described in the Boeing

747 Maintenance Manual. Repeat the

functional tests thereafter at intervals not to

exceed 1,000 hours time-in-service.

Alternative Methods of Compliance

(h)(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, Seattle

Aircraft Certification Office (ACO), 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, Seattle ACO.

(2) Alternative methods of compliance,

approved previously in accordance with AD

99–15–08, amendment 39–11227, are

approved as alternative methods of

compliance with the corresponding

requirements specified in this AD.

Note 2: 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 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.

Incorporation by Reference

(j) Except as provided by paragraphs (c)(2),

(e)(2), and (g) of this AD, the actions shall be

done in accordance with Boeing Alert

Service Bulletin 747–78A2130, dated May

26, 1994; Boeing Service Bulletin 747–

78A2166, Revision 1, dated October 9, 1997;

Lockheed Martin Service Bulletin 78–1007,

Revision 1, dated March 18, 1997; Middle

River Aircraft Systems Service Bulletin 78–

1007, Revision 2, dated March 10, 1998;

Lockheed Martin Service Bulletin 78–1020,

Revision 2, dated March 20, 1997; Middle

River Aircraft Systems Service Bulletin 78–

1020, Revision 3, dated March 16, 1998; or

Boeing Service Bulletin 747–78–2144,

Revision 1, dated April 11, 1996; as

applicable.

(1) The incorporation by reference of

Lockheed Martin Service Bulletin 78–1007,

Revision 1, dated March 18, 1997; Middle

River Aircraft Systems Service Bulletin 78–

1007, Revision 2, dated March 10, 1998;

Lockheed Martin Service Bulletin 78–1020,

Revision 2, dated March 20, 1997; Middle

River Aircraft Systems Service Bulletin 78–

1020, Revision 3, dated March 16, 1998; and

Boeing Service Bulletin 747–78–2144,

Revision 1, dated April 11, 1996; is approved

by the Director of the Federal Register in

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

part 51. Lockheed Martin Service Bulletin

78–1007, Revision 1, dated March 18, 1997,

contains the following list of effective pages:

Federal Register / Vol. 65, No. 149 / Wednesday, August 2, 2000 / Rules and Regulations 47255

Page No.

Revision level

shown on

page

Date shown on page

1, 3, 4, 22–28 .......................................................................................................................................... 1 March 18, 1997.

2, 5–21 .................................................................................................................................................... Original August 30, 1997.

Lockheed Martin Service Bulletin 78–1020,

Revision 2, dated March 20, 1997, contains

the following list of effective pages:

Page No.

Revision level

shown on

page

Date shown on page

1–5, 8, 12, 13, 15, 19–21, 23–36 ........................................................................................................... 2 March 20, 1997.

6, 7, 9–11, 14, 16–18, 22, 37 ................................................................................................................. 1 January 17, 1996.

(2) The incorporation by reference of

Boeing Service Bulletin 747–78A2166,

Revision 1, dated October 9, 1997, was

approved previously by the Director of the

Federal Register as of August 25, 1999 (64 FR

39003, July 21, 1999).

(3) The incorporation by reference of

Boeing Alert Service Bulletin 747–78A2130,

dated May 26, 1994, was approved

previously by the Director of the Federal

Register as of April 13, 1995 (60 FR 13623,

March 14, 1995).

(4) 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

September 6, 2000.

Appendix 1—Thrust Reverser ElectroMechanical Brake and CDU Cone Brake Test

1. General

A. This procedure contains steps to do two

checks:

(1) A check of the holding torque of the

electro-mechanical brake.

(2) A check of the holding torque of the

CDU cone brake.

2. Electro-Mechanical Brake and CDU Cone

Brake Torque Check

A. Prepare to do the checks:

(1) Open the fan cowl panels.

B. Do a check of the torque of the electromechanical brake:

(1) Do a check of the electro-mechanical

brake holding torque:

(a) Make sure the thrust reverser translating

cowl is extended at least one inch.

(b) Make sure the CDU lock handle is

released.

(c) Pull down on the manual release handle

on the electro-mechanical brake until the

handle fully engages the retaining clip.

Note: This will lock the electro-mechanical

brake.

(d) With the manual drive lockout cover

removed from the CDU, install a 1⁄4-inch

extension tool and dial-type torque

wrench into the drive pad.

Note: You will need a 24-inch extension to

provide adequate clearance for the torque

wrench.

(e) Apply 90 pound-inches of torque to the

system.

(i) The electro-mechanical brake system is

working correctly if the torque is reached

before you turn the wrench 450 degrees

(11⁄4 turns).

(ii) If the flexshaft turns more than 450

degrees before you reach the specified

torque, you must replace the long

flexshaft between the CDU and the upper

angle gearbox.

(iii) If you do not get 90 pound-inches of

torque, you must replace the electromechanical brake.

(f) Release the torque by turning the

wrench in the opposite direction until

you read zero pound-inches.

(i) If the wrench does not return to within

30 degrees of initial starting point, you

must replace the long flexshaft between

the CDU and upper angle gearbox.

(2) Fully retract the thrust reverser.

C. Do a check of the torque of the CDU

cone brake:

(1) Pull up on the manual release handle

to unlock the electro-mechanical brake.

(2) Pull the manual brake release lever on

the CDU to release the cone brake.

Note: This will release the pre-load tension

that may occur during a stow cycle.

(3) Return the manual brake release lever

to the locked position to engage the cone

brake.

(4) Remove the two bolts that hold the

lockout plate to the CDU and remove the

lockout plate.

(5) Install a 1⁄4-inch drive and a dial type

torque wrench into the CDU drive pad.

Caution: Do not use more than 100 poundinches of torque when you do this check.

Excessive torque will damage the CDU.

(6) Turn the torque wrench to try to

manually extend the translating cowl

until you get at lease 15-pound inches.

Note: The cone brake prevents movement

in the extend direction only. If you try to

measure the holding torque in the retract

direction, you will get a false reading.

(a) If the torque is less than 15-poundinches, you must replace the CDU.

D. Return the airplane to its usual

condition:

(1) Re-install the lockout plate.

(2) Fully retract the thrust reverser (unless

already accomplished).

(3) Pull down on the manual release

handle on the electro-mechanical brake

until the handle fully engages the

retaining clip (unless already

accomplished).

Note: This will lock the electro-mechanical

brake.

(4) Close the fan cowl panels.

Issued in Renton, Washington, on July 18,

2000.

Donald L. Riggin,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 00–18661 Filed 8–1–00; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98–NM–285–AD; Amendment

39–11840; AD 2000–15–08]

RIN 2120–AA64

Airworthiness Directives; Boeing

Model 747 Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule.

SUMMARY: This amendment supersedes

an existing airworthiness directive (AD),

applicable to certain Boeing Model 747

series airplanes, that currently requires

repetitive inspections for damage or

cracking of the aft pressure bulkhead,

and cracking of the bulkhead web-to-Yring lap joint area and the upper

segment of the bulkhead web. That AD

also requires certain follow-on actions,

if necessary. This amendment requires

that a currently required one-time