30532 Federal Register / Vol. 65, No. 93 / Friday, May 12, 2000 / Rules and Regulations

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99–NM–242–AD; Amendment

39–11717; AD 2000–09–08]

RIN 2120–AA64

Airworthiness Directives; Boeing

Model 747–100, –200, 747SP, and

747SR Series Airplanes Equipped With

Pratt & Whitney JT9D–7, –7A, –7F, and

–7J Series Engines

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule.

SUMMARY: This amendment adopts a

new airworthiness directive (AD),

applicable to certain Boeing Model 747–

100, –200, 747SP, and 747SR series

airplanes, that requires one-time

detailed visual and eddy current

inspections to detect cracking of the

nose cowl mounting flange; rework of

the nose cowl mounting flange; eddy

current inspection to detect cracking of

the reworked nose cowl mounting

flange; and corrective action, if

necessary. This amendment is prompted

by reports of the nose cowl separating

from the engine and departing the

airplane following severe engine

vibration. The actions specified by this

AD are intended to prevent separation

of the nose cowl from the engine, which

could cause collateral damage to the

airplane, and, possibly, reduced

controllability of the airplane.

DATES: Effective June 16, 2000.

The incorporation by reference of

certain publications listed in the

regulations is approved by the Director

of the Federal Register as of June 16,

2000.

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:

Dionne Krebs, Aerospace Engineer,

Propulsion Branch, ANM–140S, FAA,

Transport Airplane Directorate, Seattle

Aircraft Certification Office, 1601 Lind

Avenue, SW., Renton, Washington

98055–4056; telephone (425) 227–2250;

fax (425) 227–1181.

SUPPLEMENTARY INFORMATION: A

proposal to amend part 39 of the Federal

Aviation Regulations (14 CFR part 39) to

include an airworthiness directive (AD)

that is applicable to certain Boeing

Model 747–100, –200, 747SP, and

747SR series airplanes was published in

the Federal Register on October 6, 1999

(64 FR 54240). That action proposed to

require one-time detailed visual and

eddy current inspections to detect

cracking of the nose cowl mounting

flange; rework of the nose cowl

mounting flange; eddy current

inspection to detect cracking of the

reworked nose cowl mounting flange;

and corrective action, 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

comments received.

Support for the Proposed Rule

One commenter supports the

proposed rule.

Request to Remove Paragraph (c)

Two commenters (who otherwise

support the proposal) request that

paragraph (c) of the proposed rule be

eliminated. That paragraph reads, ‘‘As

of the effective date of this AD, no

person shall install a nose cowl on any

airplane, unless it has been inspected

and modified in accordance with

paragraph (a) of this AD.’’ One

commenter states that this paragraph

would effectively require modification

of nose cowls well before the 24-month

compliance time, which could result in

an airplane being out of service for an

extended period if an unexpected

engine change is necessary. The other

commenter states that, if paragraph (c)

is included in the final rule, the

commenter would have to purchase at

least one additional spare nose cowl,

because approximately 50 percent of its

engine changes occur at locations that

do not have a spare nose cowl. The

commenter states that if an engine

change occurs at a location that does not

have a spare modified nose cowl, the

time necessary to return the airplane to

service will increase by at least six

hours, which would result in lengthy

flight delays or cancellations that would

be costly and would cause disruptions

for the traveling public. The commenter

states that purchasing a new spare nose

cowl would be expensive and would

require a lead time of 300 days.

The FAA concurs with the

commenters’ request to eliminate

paragraph (c) of the proposed rule. The

FAA’s intent is to allow operators to

accomplish the necessary inspections

and rework during a regularly

scheduled maintenance interval.

Therefore, paragraph (c) of the proposed

rule has not been included in this final

rule. The FAA finds that eliminating

paragraph (c) of the proposed rule will

not adversely impact the safety of the

affected airplane fleet and will allow

more flexibility for operators in

complying with the requirements within

the specified compliance time.

Request to Extend Compliance Time

One commenter requests that

paragraph (a) of the proposed rule be

revised to extend the compliance time

from 24 months, as proposed, to 36

months. The commenter states that the

‘‘very aggressive incorporation rate

requirements’’ are not justified, given

that there have been few incidents of

nose cowl separations. The commenter

states that extending the compliance

time would allow the required actions

to be accomplished during scheduled

maintenance opportunities.

The FAA does not concur with the

commenter’s request. In developing an

appropriate compliance time for this

action, the FAA considered the safety

implications, parts availability, and

normal maintenance schedules for

timely accomplishment of the

requirements of this AD. In

consideration of these items, as well as

the reports of six in-service nose cowl

separations, the FAA has determined

that 24 months represents an

appropriate interval of time allowable

wherein the modifications can be

accomplished during scheduled

maintenance intervals for the majority

of affected operators and an acceptable

level of safety can be maintained. No

change to the final rule is necessary in

this regard.

Challenge to Justification for Proposed

Requirements

One commenter, an operator, states

that, while it has no technical objection

to the rework of the nose cowl mounting

flange described in the proposed rule, it

cannot recall any incident on its fleet of

affected airplanes, in which ingestion of

a foreign object into the engine resulted

in separation of the nose cowl. The

commenter questions the conditions

that existed and the events that occurred

during the incidents of nose cowl

separation referenced in the proposed

rule. The commenter challenges the

justification for the proposed

requirements if the FAA determines that

unique conditions or circumstances led

to the incidents in question. The

commenter makes no specific request

for a change to the proposed rule.

Federal Register / Vol. 65, No. 93 / Friday, May 12, 2000 / Rules and Regulations 30533

The FAA infers that the commenter is

requesting that the FAA consider

withdrawing the proposed rule. The

FAA does not concur. The information

that the FAA has received regarding

incidents of nose cowl separation does

not suggest that there were any

conditions common to all incidents

besides the configuration of the nose

cowl mounting flange. The information

has led the FAA to determine that the

37-bolt mounting flange configuration is

not adequate to retain the nose cowl on

Pratt & Whitney JT9D series engines,

and that the modification of the nose

cowl mounting flange described in the

proposed rule is necessary. No change

to the final rule is necessary in this

regard.

Request to Remove References to

‘‘Reduced Controllability of the

Airplane’’

One commenter states that, ‘‘To date,

no evidence of reduced airplane

controllability during or after separation

[of the nose cowl] has been reported.’’

The commenter makes no specific

request and provides no further

information related to its comment.

The FAA infers that the commenter is

requesting that references to ‘‘reduced

controllability of the airplane’’ be

removed from the proposed rule. The

FAA concurs with the commenter’s

statement that there have been no

reported instances of reduced airplane

controllability during or after the

separation of a nose cowl. However, the

potential exists for reduced

controllability during or after the

separation of a nose cowl, if the

separated nose cowl comes into contact

with the airplane. This possibility is the

basis for determining that the separation

of a nose cowl is an unsafe condition.

Therefore, the FAA finds that no change

to the final rule is necessary in this

regard.

Request to Revise ‘‘Explanation of

Relevant Service Information’’ Section

One commenter, the manufacturer,

states that the service bulletin

referenced in the proposed rule was

issued not as an inspection bulletin to

detect cracking in the mounting flange,

but, instead, to provide instructions for

strengthening the attachment capability

of the nose cowl by increasing the

number of attachment fasteners. The

commenter also states that it has not

received reports of cracking in the nose

cowl flange, nor has cracking been

identified as the cause of the nose cowl

separation. The commenter further

states that the eddy current and detailed

visual inspections described in the

service bulletin are a common

maintenance/rework practice after

machining operations such as drilling

holes, to ensure that no damage was

done during the operation.

The commenter makes no specific

request for a change to the proposed

rule. However, the FAA infers that the

commenter is requesting that the

‘‘Explanation of Relevant Service

Information’’ section of the proposed

rule be revised to eliminate references to

cracking and to clarify the purpose of

the eddy current and detailed visual

inspections. The FAA concurs with the

commenter’s description of the intent of

the service bulletin; however, because

the referenced section is not restated in

the final rule, no change to this section

is necessary. In response to this

comment, the FAA has also reviewed

the explanation of the unsafe condition

in the ‘‘Discussion’’ section of the

proposed rule, and finds that the section

accurately describes the intent and

background of the proposed rule. No

change to the final rule is necessary in

this regard.

Request to Revise Cost Impact Estimate

One commenter requests an increase

in the cost estimate of the proposed

rule. The commenter points out that the

proposed rule estimates that it will take

approximately 19 work hours per

airplane to accomplish the proposed

actions, while the service bulletin

estimates approximately 34 work hours

per airplane for the actions described in

the service bulletin. Also, the

commenter points out that the cost

figures in the proposed rule do not

account for the cost of accomplishing

the proposed actions on spare nose

cowls, which the commenter estimates

will take approximately 5.5 work hours

per nose cowl.

The FAA infers that the commenter is

requesting that the cost impact

information in the final rule be revised

to reflect the service bulletin estimates

and to incorporate the estimated cost for

inspecting and reworking spares. The

FAA does not concur with the

commenter’s request. The cost impact

information in AD rulemaking actions

describes only the ‘‘direct’’ costs of the

specific actions required by this AD.

The number of work hours necessary to

accomplish the required actions

(specified as 19 in the cost impact

information in the proposed rule and

restated below) was provided to the

FAA by the manufacturer based on the

best data available to date. This number

represents the time necessary to perform

only the actions actually required by

this AD. The FAA recognizes that, in

accomplishing the requirements of any

AD, operators may incur ‘‘incidental’’

costs in addition to the ‘‘direct’’ costs.

The cost analysis in AD rulemaking

actions, however, typically does not

include incidental costs, such as the

time required to gain access and close

up, planning time, or time necessitated

by other administrative actions. Because

incidental costs may vary significantly

from operator to operator, they are

almost impossible to calculate. In

addition, the estimated cost to modify

‘‘spare’’ parts is not typically included

in AD rulemaking actions. No change to

the final rule is necessary in this regard.

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 257

airplanes of the affected design in the

worldwide fleet. The FAA estimates that

106 airplanes of U.S. registry will be

affected by this AD, that it will take

approximately 19 work hours per

airplane to accomplish the required

actions, and that the average labor rate

is $60 per work hour. Required parts

will cost approximately $500 per

airplane. Based on these figures, the cost

impact of the AD on U.S. operators is

estimated to be $173,840, or $1,640 per

airplane.

The cost impact figure discussed

above is 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)

30534 Federal Register / Vol. 65, No. 93 / Friday, May 12, 2000 / Rules and Regulations

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

adding the following new airworthiness

directive:

2000–09–08 Boeing: Amendment 39–11717.

Docket 99–NM–242–AD.

Applicability: Model 747–100, –200,

747SP, and 747SR series airplanes;

certificated in any category; equipped with

Pratt & Whitney JT9D–7, –7A, –7F, and –7J

series engines.

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 (c) 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 separation of the nose cowl

from the engine, which could cause collateral

damage to the airplane, and, possibly,

reduced controllability of the airplane,

accomplish the following:

One-Time Inspections and Rework

(a) Within 24 months after the effective

date of this AD, perform one-time detailed

visual and eddy current inspections to detect

cracking of the existing nose cowl mounting

flange, rework the nose cowl mounting flange

to increase the number of attachment fastener

holes from 37 to 67, and perform a one-time

eddy current inspection to detect cracking of

the new fastener holes in the reworked nose

cowl mounting flange, in accordance with

the Accomplishment Instructions of Boeing

Service Bulletin 747–71–2290, dated March

18, 1999.

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 aides such as

mirror, magnifying lenses, etc., may be used.

Surface cleaning and elaborate access

procedures may be required.’’

Corrective Action

(b) If any crack is found during any

inspection required by paragraph (a) of this

AD: Prior to further flight, repair in

accordance with a method approved by the

Manager, Seattle Aircraft Certification Office

(ACO), FAA, Transport Airplane Directorate.

Alternative Methods of Compliance

(c) 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 Permits

(d) 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

(e) Except as provided by paragraph (b) of

this AD, the actions shall be done in

accordance with Boeing Service Bulletin

747–71–2290, dated March 18, 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

(f) This amendment becomes effective on

June 16, 2000.

Issued in Renton, Washington, on May 3,

2000.

Vi L. Lipski,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 00–11545 Filed 5–11–00; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99–NM–212–AD; Amendment

39–11716; AD 2000–09–07]

RIN 2120–AA64

Airworthiness Directives; McDonnell

Douglas Model DC–10–10, –15, –30,

–30F, and –40 Series Airplanes, and

KC–10A (Military) Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule.

SUMMARY: This amendment adopts a

new airworthiness directive (AD),

applicable to certain McDonnell

Douglas Model DC–10–10, –15, –30,

–30F, and –40 series airplanes, and KC–

10A (military) airplanes, that requires a

one-time general visual inspection of

circuit breakers to determine the

manufacturer of the circuit breakers,

and corrective action, if necessary. This

amendment is prompted by incidents of

smoke and electrical odor in the flight

compartment and cabin area as a result

of failure of circuit breakers. The actions

specified by this AD are intended to

prevent internal overheating and arcing

of circuit breakers and airplane wiring

due to long-term use and breakdown of

internal components of the circuit

breakers, which could result in smoke

and fire in the flight compartment and

main cabin.

DATES: Effective June 16, 2000.

The incorporation by reference of

certain publications listed in the

regulations is approved by the Director

of the Federal Register as of June 16,

2000.

ADDRESSES: The service information

referenced in this AD may be obtained

from Boeing Commercial Aircraft

Group, Long Beach Division, 3855

Lakewood Boulevard, Long Beach,

California 90846, Attention: Technical

Publications Business Administration,

Dept. C1–L51 (2–60). 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 FAA,