Federal Register / Vol. 65, No. 77 / Thursday, April 20, 2000 / Proposed Rules 21157

the methods and times specified in the

service bulletin.

(3) If any crack is found that is greater than

30 mm, but less than 100 mm: Prior to the

accumulation of 250 landings after crack

discovery, repair in accordance with a

method approved by the Manager,

International Branch, ANM–116; or the

Direction Ge ́ne ́rale de l’Aviation Civile

(DGAC) (or its delegated agent).

(4) If any crack is found that is greater than

or equal to 100 mm: Prior to further flight,

repair in accordance with a method approved

by the Manager, International Branch, ANM–

116; or the DGAC (or its delegated agent).

(5) Accomplishment of the modification

specified in Airbus Industrie Service Bulletin

A300–54–6019, dated October 15, 1993,

increases the threshold and repetitive

interval of the inspections required by

paragraph (b) of this AD to the threshold and

interval specified in paragraph 2.D. of the

Accomplishment Instructions of Airbus

Industrie Service Bulletin A300–54–6011,

Revision 1, dated October 15, 1993.

New Requirements of This AD

Model A310 Series Airplanes

(c) For Model A310–221, –222, –322, –324,

and –325 series airplanes: Perform an

internal eddy current inspection to detect

cracks in the lower spar axis of the pylon

between ribs 9 and 10, in accordance with

Airbus Industrie Service Bulletin A310–54–

2016, dated November 12, 1991; or Revision

1, dated October 15, 1993; or Revision 2,

dated June 11, 1999; at the time specified in

paragraph (d) of this AD.

(1) If no crack is found, repeat the

inspection thereafter at intervals not to

exceed 2,500 landings.

(2) If any crack is found that is less than

or equal to 30 mm: Perform subsequent

inspections and repair in accordance with

the methods and times specified in the

service bulletin.

(3) If any crack is found that is greater than

30 mm, but less than 100 mm: Prior to the

accumulation of 250 landings after crack

discovery, repair in accordance with a

method approved by the Manager,

International Branch, ANM–116; or the

DGAC (or its delegated agent).

(4) If any crack is found that is greater than

or equal to 100 mm: Prior to further flight,

repair in accordance with a method approved

by the Manager, International Branch, ANM–

116; or the DGAC (or its delegated agent).

(5) Accomplishment of the modification

specified in Airbus Industrie Service Bulletin

A310–54–2022, dated October 15, 1993; or

Revision 1, dated March 16, 1999; increases

the threshold and repetitive interval of the

inspections required by paragraph (c) of this

AD to the threshold and interval specified in

paragraph 2.D. of the Accomplishment

Instructions of Airbus Industrie Service

Bulletin A310–54–2016, Revision 02, dated

June 11, 1999.

(d) Perform the initial inspection required

by paragraph (c) of this AD at the earlier of

the times specified by paragraphs (d)(1) and

(d)(2) of this AD.

(1) Prior to the accumulation of 25,000

total landings, or within 500 landings after

June 12, 1995, whichever occurs later.

(2) At the applicable time specified by

paragraph (d)(2)(i), (d)(2)(ii), or (d)(2)(iii) of

this AD.

(i) For airplanes that have accumulated

fewer than 10,000 landings as of the effective

date of this AD: Perform the inspection prior

to the accumulation of 3,800 total landings,

or within 1,500 landings after the effective

date of this AD, whichever occurs later.

(ii) For airplanes that have accumulated

10,000 total landings or more, but fewer than

20,000 total landings, as of the effective date

of this AD: Perform the inspection within

1,000 landings after the effective date of this

AD.

(iii) For airplanes that have accumulated

20,000 total landings or more as of the

effective date of this AD: Perform the

inspection within 500 landings after the

effective date of this AD.

Alternative Methods of Compliance

(e) 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.

Note 2: 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 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.

Note 3: The subject of this AD is addressed

in French airworthiness directive 1999–237–

285(B), dated June 2, 1999.

Issued in Renton, Washington, on April 14,

2000.

Charles D. Huber,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 00–9898 Filed 4–19–00; 8:45 am]

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98–NM–164–AD]

RIN 2120–AA64

Airworthiness Directives; Airbus Model

A300–600 Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes the

supersedure of an existing airworthiness

directive (AD), applicable to certain

Airbus Model A300–600 series

airplanes, that currently requires

repetitive ultrasonic inspections to

detect cracks in the bolt holes inboard

and outboard of rib 9 on the bottom

booms of the front and rear wing spars,

and repair, if necessary. This action

would revise the compliance thresholds

for the inspection and would require

that the inspections be repeated at

reduced intervals. This proposal is

prompted by issuance of mandatory

continuing airworthiness information by

a foreign civil airworthiness authority.

The actions specified by the proposed

AD are intended to prevent fatigue

cracks in the bolt holes of the wing

spars, which could result in reduced

structural integrity of a wing spar.

DATES: Comments must be received by

May 22, 2000.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 98–NM–

164–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.

The service information referenced in

the proposed rule may be obtained from

Airbus Industrie, 1 Rond Point Maurice

Bellonte, 31707 Blagnac Cedex, France.

This information may be examined at

the FAA, Transport Airplane

Directorate, 1601 Lind Avenue, SW.,

Renton, Washington.

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:

Comments Invited

Interested persons are invited to

participate in the making of the

proposed rule by submitting such

written data, views, or arguments as

they may desire. Communications shall

identify the Rules Docket number and

be submitted in triplicate to the address

specified above. All communications

received on or before the closing date

for comments, specified above, will be

considered before taking action on the

proposed rule. The proposals contained

21158 Federal Register / Vol. 65, No. 77 / Thursday, April 20, 2000 / Proposed Rules

in this notice may be changed in light

of the comments received.

Comments are specifically invited on

the overall regulatory, economic,

environmental, and energy aspects of

the proposed rule. All comments

submitted will be available, both before

and after the closing date for comments,

in the Rules Docket for examination by

interested persons. A report

summarizing each FAA-public contact

concerned with the substance of this

proposal will be filed in the Rules

Docket.

Commenters wishing the FAA to

acknowledge receipt of their comments

submitted in response to this notice

must submit a self-addressed, stamped

postcard on which the following

statement is made: ‘‘Comments to

Docket Number 98–NM–164–AD.’’ The

postcard will be date stamped and

returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this

NPRM by submitting a request to the

FAA, Transport Airplane Directorate,

ANM–114, Attention: Rules Docket No.

98–NM–164–AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

On March 29, 1995, the FAA issued

AD 95–07–05, amendment 39–9187 (60

FR 17990, April 10, 1995), applicable to

certain Airbus Model A300–600 series

airplanes, to require repetitive

ultrasonic inspections to detect fatigue

cracks in the bolt holes inboard and

outboard of rib 9 on the bottom booms

of the front and rear wing spars, and

repair, if necessary. That action was

prompted by the discovery of fatigue

cracks that emanated from the bolt holes

inboard and outboard of rib 9 in the

bottom booms of the front and rear wing

spars. The requirements of that AD are

intended to prevent cracks in the bolt

holes of the wing spars, which could

result in reduced structural integrity of

a wing spar.

Actions Since Issuance of Previous Rule

Since the issuance of that AD, the

Direction G ́en ́erale de l’Aviation Civile

(DGAC), which is the airworthiness

authority for France, received a report

indicating that, during routine

maintenance, a fatigue crack of 3.58

inches (91 millimeters) in length was

discovered on the bolt holes of the wing

spars on a Model A300 series airplane

that had accumulated 29,919 total flight

cycles. Investigation revealed that an

initial inspection to detect cracks in the

bolt holes of the wing spars, in

accordance with that AD, had been

performed on this airplane at 23,545

total flight cycles. Procedures for this

inspection are described in Airbus

Service Bulletin A300–57–6039, dated

August 1, 1994 (which was referenced

in AD 95–07–05 as the appropriate

source of service information).

That service bulletin specified an

interval not to exceed 9,000 flight cycles

for repetitive inspections, which would

have resulted in accomplishment of the

next inspection on this airplane at

32,545 total flight cycles.

Accomplishment of the next inspection

at the scheduled compliance time

would have allowed the cracking on this

airplane to remain undetected for 2,626

flight cycles. Therefore, the DGAC has

concluded that the existing repetitive

interval for these inspections does not

detect such cracking in a timely manner,

and advises that the interval should be

reduced.

Explanation of Relevant Service

Information

Subsequent to the finding of this new

cracking, Airbus issued Service Bulletin

A300–57–6037, Revision 1, dated

August 31, 1995. The inspection and

repair procedures described in Revision

1 of the service bulletin are essentially

identical to those described in the

original issue of the service bulletin.

However, Revision 1 of the service

bulletin reduces the repetitive

inspection intervals from 9,000 flight

cycles, as specified in the original issue

of the service bulletin, to 4,800 flight

cycles.

The DGAC classified Revision 1 of

this service bulletin as mandatory and

issued French airworthiness directive

94–208–169(B)R2, dated October 8,

1997, in order to assure the continued

airworthiness of these airplanes in

France.

FAA’s Conclusions

This airplane model is manufactured

in France and is type certificated for

operation in the United States under the

provisions of section 21.29 of the

Federal Aviation Regulations (14 CFR

21.29) and the applicable bilateral

airworthiness agreement. Pursuant to

this bilateral airworthiness agreement,

the DGAC has kept the FAA informed

of the situation described above. The

FAA has examined the findings of the

DGAC, reviewed all available

information, and determined that AD

action is necessary for products of this

type design that are certificated for

operation in the United States.

Explanation of Requirements of

Proposed Rule

Since an unsafe condition has been

identified that is likely to exist or

develop on other airplanes of the same

type design registered in the United

States, the proposed AD would

supersede AD 95–07–05 to continue to

require repetitive ultrasonic inspections

to detect cracks in the bolt holes inboard

and outboard of rib 9 on the bottom

booms of the front and rear wing spars,

and repair, if necessary. This proposed

AD would require that the repetitive

inspections be accomplished at a

revised threshold and at reduced

intervals. The actions would be required

to be accomplished in accordance with

the service bulletin described

previously, except as discussed below.

Differences Between Proposed Rule and

Service Bulletin

Operators should note that, unlike

particular provisions in the service

bulletin regarding adjustment of the

compliance times using an ‘‘adjustmentfor-range’’ formula, this proposed AD

would not permit formulaic adjustments

of the inspection compliance times. The

FAA has determined that such

adjustments may present difficulties in

determining if the applicable

inspections and modifications have

been accomplished within the

appropriate time frame. Further, while

such adjustable compliance times are

utilized as part of the Maintenance

Review Board program, they do not fit

practically into the AD tracking process

for operators or for Principal

Maintenance Inspectors attempting to

ascertain compliance with AD’s.

Therefore, the FAA has determined that

fixed compliance times should be

specified for accomplishment of the

actions required by this AD.

Additionally, after discussions with

the DGAC and the manufacturer, the

FAA has determined that flight-hour

maximums should be included as part

of the compliance threshold and

repetitive intervals for the inspections

required by this proposed AD. Inclusion

of a compliance threshold in terms of

total flight hours as well as total flight

cycles, and requiring inspection at the

earlier of those times, will ensure that

airplanes with longer-than-average flight

times are inspected at a threshold and

intervals necessary to maintain safety.

Accordingly, the FAA has specified that

the initial inspection must be

accomplished at the earliest time an

airplane reaches certain accumulated

total flight cycles or total flight hours,

and that repetitive inspections are to be

accomplished at intervals not to exceed

certain flight cycles or flight hours,

whichever occurs first.

The FAA has determined that such

revision of the inspection threshold and

Federal Register / Vol. 65, No. 77 / Thursday, April 20, 2000 / Proposed Rules 21159

reduction of the intervals of the existing

AD does not adversely impact any U.S.

operators, since no airplanes on the U.S.

Register have yet reached those

accumulated flight-cycle or flight-hour

thresholds.

Cost Impact

There are approximately 75 airplanes

of U.S. registry that would be affected

by this proposed AD.

The inspection that is currently

required by AD 95–07–05, and retained

in this AD, takes approximately 1 work

hour per airplane to accomplish

(excluding 10 work hours for access and

close-up), at an average labor rate of $60

per work hour. Based on this figure, the

cost impact of the currently required

inspection on U.S. operators is

estimated to be $4,500, or $60 per

airplane, per inspection cycle.

The cost impact figure discussed

above is based on assumptions that no

operator has yet accomplished any of

the current or proposed requirements of

this AD action, and that no operator

would accomplish those actions in the

future if this AD were not adopted.

Regulatory Impact

The regulations proposed herein

would not have a substantial direct

effect on the States, on the relationship

between the national Government and

the States, or on the distribution of

power and responsibilities among the

various levels of government. Therefore,

it is determined that this proposal

would not have federalism implications

under Executive Order 13132.

For the reasons discussed above, I

certify that this proposed regulation (1)

is not a ‘‘significant regulatory action’’

under Executive Order 12866; (2) is not

a ‘‘significant rule’’ under the DOT

Regulatory Policies and Procedures (44

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

promulgated, will not have a significant

economic impact, positive or negative,

on a substantial number of small entities

under the criteria of the Regulatory

Flexibility Act. A copy of the draft

regulatory evaluation prepared for this

action is contained in the Rules Docket.

A copy of it may be obtained by

contacting the Rules Docket at the

location provided under the caption

ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation

safety, Safety.

The Proposed Amendment

Accordingly, pursuant to the

authority delegated to me by the

Administrator, the Federal Aviation

Administration proposes to amend part

39 of the Federal Aviation Regulations

(14 CFR part 39) as follows:

PART 39—AIRWORTHINESS

DIRECTIVES

1. The authority citation for part 39

continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

§ 39.13 [Amended]

2. Section 39.13 is amended by

removing amendment 39–9187 (60 FR

17990, April 10, 1995), and by adding

a new airworthiness directive (AD), to

read as follows:

Airbus Industrie: Docket 98–NM–164–AD.

Supersedes AD 95–07–05, Amendment

39–9187.

Applicability: Model A300–600 series

airplanes, certificated in any category, on

which Airbus Modification 10161 has not

been installed in production.

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 (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 fatigue cracks in the bolt holes

of the wing spars, which could result in

reduced structural integrity of a wing spar,

accomplish the following:

Ultrasonic Inspections

(a) Perform an ultrasonic inspection to

detect fatigue cracking of the bolt holes

inboard and outboard of rib 9 on the bottom

booms of the front and rear wing spars, in

accordance with Airbus Service Bulletin

A300–57–6037, dated August 1, 1994, or

Revision 1, dated August 31, 1995, at the

applicable time specified in paragraph (a)(1)

or (a)(2) of this AD. Repeat the inspection

thereafter at intervals not to exceed 4,800

flight cycles or 11,000 flight hours,

whichever occurs first.

(1) For airplanes on which Airbus

Modification 8842 (reference Airbus Service

Bulletin A300–57–6039) has not been

installed: Inspect at the earlier of the times

specified by paragraphs (a)(1)(i) and (a)(1)(ii)

of this AD.

(i) Prior to the accumulation of 17,000 total

flight cycles, or within 2,000 flight cycles

after May 10, 1995 (the effective date of AD

95–07–05, amendment 39–9187), whichever

occurs later.

(ii) Prior to the accumulation of 39,000

total flight hours.

(2) For airplanes on which Airbus

Modification 8842 has been installed: Inspect

at the earlier of the times specified by

paragraphs (a)(2)(i) and (a)(2)(ii) of this AD.

(i) Within 17,000 flight cycles after

accomplishment of Airbus Modification

8842, or within 2,000 flight cycles after May

10, 1995, whichever occurs later.

(ii) Within 39,000 flight hours after

accomplishment of Airbus Modification

8842.

Corrective Action

(b) If any crack is found, prior to further

flight, repair in accordance with Airbus

Service Bulletin A300–57–6037, dated

August 1, 1994, or Revision 1, dated August

31, 1995. Thereafter, perform the repetitive

inspections required by paragraph (a) of this

AD.

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,

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.

Note 2: 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

(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.

Note 3: The subject of this AD is addressed

in French airworthiness directive 94–208–

169(B)R2, dated October 8, 1997.

Issued in Renton, Washington, on April 14,

2000.

Charles D. Huber,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 00–9899 Filed 4–19–00; 8:45 am]

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99–SW–81–AD]

Airworthiness Directives; Sikorsky

Aircraft-manufactured Model CH–54A

Helicopters

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).