This section of the FEDERAL REGISTER

contains regulatory documents having general

applicability and legal effect, most of which

are keyed to and codified in the Code of

Federal Regulations, which is published under

50 titles pursuant to 44 U.S.C. 1510.

The Code of Federal Regulations is sold by

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new books are listed in the first FEDERAL

REGISTER issue of each week.

Rules and Regulations Federal Register

21633

Vol. 65, No. 79

Monday, April 24, 2000

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000–NM–88–AD; Amendment

39–11694; AD 2000–08–08]

RIN 2120–AA64

Airworthiness Directives; Boeing

Model 737–600, –700, and –800 Series

Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule; request for

comments.

SUMMARY: This amendment adopts a

new airworthiness directive (AD) that is

applicable to certain Boeing Model 737–

600, –700, and –800 series airplanes.

This action requires a one-time

inspection to detect cracking of the rear

spar stiffeners in the wing center

section; and modification of crack-free

stiffeners, or repair of cracked stiffeners.

This amendment is prompted by a

report of severed rear spar stiffeners of

the center wing, which resulted in

cracking in the adjacent keel beam

structure. The actions specified in this

AD are intended to prevent failure of the

keel beam structure.

DATES: Effective May 9, 2000.

The incorporation by reference of

certain publications listed in the

regulations is approved by the Director

of the Federal Register as of May 9,

2000.

Comments for inclusion in the Rules

Docket must be received on or before

June 23, 2000.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 2000–NM–

88–AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055–4056.

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:

Nenita Odesa, Aerospace Engineer,

Airframe Branch, ANM–120S, FAA,

Transport Airplane Directorate, 1601

Lind Avenue, SW., Renton, Washington

98055–4056; telephone (425) 227–2557;

fax (425) 227–1181.

SUPPLEMENTARY INFORMATION: The FAA

has received a report of severed rear

spar stiffeners of the center wing, which

were found during fatigue testing of the

Model 737–800 series airplane. The

cracks were located in the stiffeners at

the left and right buttock lines 6.15, and

initiated at fastener holes below the

lower chord of the rear spar. The broken

stiffeners were caused by actual stresses

being higher than those used for design

of the structure. Failure of the stiffeners

caused cracking in the adjacent keel

beam structure. This condition, if not

corrected, could result in failure of the

keel beam structure.

Model 737–600 and –700 series

airplanes have a similar structural

design and are therefore also subject to

the identified unsafe condition.

Explanation of Relevant Service

Information

The FAA has reviewed and approved

Boeing Service Bulletin 737–57–1253,

dated December 16, 1999, which

describes procedures for a one-time

high-frequency eddy current inspection

to detect cracking in the rear spar

stiffeners at the fastener holes below the

lower rear spar chord of the wing center

section. For crack-free stiffeners, the

service bulletin recommends a

preventive modification, which involves

installing nested angles at the stiffeners

at the left and right buttock lines 6.15.

For any cracked stiffener, the service

bulletin recommends, among other

things, replacement of that stiffener.

Accomplishment of the actions

specified in the service bulletin is

intended to adequately address the

identified unsafe condition.

Explanation of the Requirements of the

Rule

Since an unsafe condition has been

identified that is likely to exist or

develop on other airplanes of the same

type design, this AD is being issued to

prevent failure of the keel beam

structure. This AD requires

accomplishment of the actions specified

in the service bulletin described

previously, except as discussed below.

Differences Between the Rule and

Relevant Service Information

The service bulletin recommends that

cracked stiffeners be replaced and that

further repair be accomplished in

accordance with instructions from

Boeing. However, this AD requires that

repair of any cracked stiffener be

accomplished in accordance with a

method approved by the FAA.

Determination of Rule’s Effective Date

Since a situation exists that requires

the immediate adoption of this

regulation, it is found that notice and

opportunity for prior public comment

hereon are impracticable, and that good

cause exists for making this amendment

effective in less than 30 days.

Comments Invited

Although this action is in the form of

a final rule that involves requirements

affecting flight safety and, thus, was not

preceded by notice and an opportunity

for public comment, comments are

invited on this rule. Interested persons

are invited to comment on this 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

under the caption ADDRESSES. All

communications received on or before

the closing date for comments will be

considered, and this rule may be

amended in light of the comments

received. Factual information that

supports the commenter’s ideas and

suggestions is extremely helpful in

evaluating the effectiveness of the AD

action and determining whether

additional rulemaking action would be

needed.

Comments are specifically invited on

the overall regulatory, economic,

environmental, and energy aspects of

the rule that might suggest a need to

modify the rule. All comments

21634 Federal Register / Vol. 65, No. 79 / Monday, April 24, 2000 / Rules and Regulations

submitted will be available, both before

and after the closing date for comments,

in the Rules Docket for examination by

interested persons. A report that

summarizes each FAA-public contact

concerned with the substance of this AD

will be filed in the Rules Docket.

Commenters wishing the FAA to

acknowledge receipt of their comments

submitted in response to this rule must

submit a self-addressed, stamped

postcard on which the following

statement is made: ‘‘Comments to

Docket Number 2000–NM–88–AD.’’ The

postcard will be date stamped and

returned to the commenter.

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.

The FAA has determined that this

regulation is an emergency regulation

that must be issued immediately to

correct an unsafe condition in aircraft,

and that it is not a ‘‘significant

regulatory action’’ under Executive

Order 12866. It has been determined

further that this action involves an

emergency regulation under DOT

Regulatory Policies and Procedures (44

FR 11034, February 26, 1979). If it is

determined that this emergency

regulation otherwise would be

significant under DOT Regulatory

Policies and Procedures, a final

regulatory evaluation will be prepared

and placed in the Rules Docket. A copy

of it, if filed, 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

adding the following new airworthiness

directive:

2000–08–08 Boeing: Amendment 39–11694.

Docket 2000–NM–88–AD.

Applicability: Model 737–600, –700, and

–800 series airplanes; certificated in any

category; line numbers 1 through 321

inclusive.

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 failure of the keel beam

structure, accomplish the following:

Inspection

(a) Prior to the accumulation of the total

number of flight cycles specified by Table 1,

‘‘Compliance Thresholds,’’ as applicable, of

Boeing Service Bulletin 737–57–1253, dated

December 16, 1999; or within 60 days after

the effective date of this AD, whichever

occurs later: Perform a one-time highfrequency eddy current inspection to detect

cracking of the rear spar stiffeners that are

located at the left and right buttock lines 6.15

of the wing center section, in accordance

with the service bulletin.

(1) If no cracking is detected in either

stiffener: Prior to further flight, install the

preventive modification on that stiffener, in

accordance with the service bulletin.

(2) If any cracking is found in either

stiffener, prior to further flight, repair that

stiffener 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 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 by the

Manager, Seattle ACO, as required by this

paragraph, the Manager’s approval letter

must specifically reference this AD.

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, 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 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

(c) 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

(d) Except as required by paragraph (a)(2)

of this AD, the actions shall be done in

accordance with Boeing Service Bulletin

737–57–1253, dated December 16, 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.

(e) This amendment becomes effective on

May 9, 2000.

Issued in Renton, Washington, on April 14,

2000.

Charles D. Huber,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 00–9895 Filed 4–21–00; 8:45 am]

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99–SW–28–AD; Amendment

39–11691; AD 2000–08–05]

RIN 2120–AA64

Airworthiness Directives; Agusta

Model A109C and A109K2 Helicopters

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule.

SUMMARY: This amendment supersedes

an existing airworthiness directive (AD),

applicable to Agusta Model A109C and

A109K2 helicopters, that currently

requires removing the main rotor pitch

control link assemblies, measuring the

radial play of each upper and lower

spherical rod-end bearing (bearing), and

replacing any unairworthy bearing. This

amendment requires replacing the pitch

control link assembly with an assembly

that has increased durability and wear

resistance. This amendment is

prompted by reports of increased

helicopter vibration caused by wear of