Federal Register / Vol. 65, No. 28 / Thursday, February 10, 2000 / Proposed Rules 6565

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99–NM–371–AD]

RIN 2120–AA64

Airworthiness Directives; Bombardier

Model DHC–8–100, –200, and –300

Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes the

adoption of a new airworthiness

directive (AD) that is applicable to

certain Bombardier Model DHC–8–100,

–200, and –300 series airplanes. This

proposal would require a one-time

detailed visual inspection to detect

damage of the ladder plates and access

cover areas of the upper surface of the

wings, repair, if necessary, and

installation of new O-ring seals. 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 damage of the

upper wing ladder plates, which could

result in displacement of the adjacent

channel seals and consequent reduced

lightning strike protection of the fuel

tanks.

DATES: Comments must be received by

March 13, 2000.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 99–NM–

371–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

Bombardier, Inc., Bombardier Regional

Aircraft Division, 123 Garrett Boulevard,

Downsview, Ontario M3K 1Y5, Canada.

This information may be examined at

the FAA, Transport Airplane

Directorate, 1601 Lind Avenue, SW.,

Renton, Washington; or at the FAA,

Engine and Propeller Directorate, New

York Aircraft Certification Office, 10

Fifth Street, Third Floor, Valley Stream,

New York.

FOR FURTHER INFORMATION CONTACT:

James E. Delisio, Aerospace Engineer,

Airframe and Propulsion Branch, ANE–

171, FAA, Engine and Propeller

Directorate, New York Aircraft

Certification Office, 10 Fifth Street,

Third Floor, Valley Stream, New York

11581; telephone (516) 256–7521; fax

(516) 568–2716.

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

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 99–NM–371–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.

99–NM–371–AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

Transport Canada Civil Aviation

(TCCA), which is the airworthiness

authority for Canada, notified the FAA

that an unsafe condition may exist on

certain Bombardier Model DHC–8–100,

–200, and –300 series airplanes. TCCA

advises that, during maintenance, a

sealing problem was detected in the

access panels of the upper wing fuel

tanks. Investigation revealed that the

diameter of the O-ring seals installed

during manufacture on certain airplanes

may be too large for the grooves of the

access panels of the upper wing fuel

tanks. The large diameter O-ring seals

can prevent the fuel tank access panels

from fitting properly to the upper wing

ladder plates. This improper fit could

lead to fretting and corrosion damage of

the upper wing ladder plates. Such

damage, if not detected and corrected,

could result in displacement of the

adjacent channel seals and consequent

reduced lightning strike protection of

the fuel tanks.

Explanation of Relevant Service

Information

The manufacturer has issued

Bombardier Service Bulletin S.B. 8–57–

41, Revision ‘A’, dated July 28, 1999,

which describes procedures for a onetime detailed visual inspection to detect

damage (i.e., fretting and/or corrosion)

of the ladder plates and access cover

areas of the upper surface of the wings.

The service bulletin also describes

procedures for installing new 0.103 inch

diameter O-ring seals. Accomplishment

of the actions specified in the service

bulletin is intended to adequately

address the identified unsafe condition.

TCCA classified this service bulletin as

mandatory and issued Canadian

airworthiness directive CF–99–20, dated

July 20, 1999, in order to assure the

continued airworthiness of these

airplanes in Canada.

FAA’s Conclusions

This airplane model is manufactured

in Canada 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,

TCCA has kept the FAA informed of the

situation described above. The FAA has

examined the findings of TCCA,

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 require

accomplishment of the actions specified

in the service bulletin described

previously, except as discussed below.

Differences Between Proposed AD and

Service Bulletin

Operators should note that, although

the Bombardier service bulletin

specifies that the manufacturer may be

6566 Federal Register / Vol. 65, No. 28 / Thursday, February 10, 2000 / Proposed Rules

contacted for disposition of certain

conditions, this proposal would require

the repair of those conditions to be

accomplished in accordance with a

method approved by the FAA.

Additionally, operators should note

that, the Bombardier service bulletin

does not provide procedures for repair

of damage within certain limits.

However, this proposed AD would

require the repair of damage that is

determined to be within certain limits;

the repair would be required to be

accomplished in accordance with the

Structure Repair Manual (SRM).

Cost Impact

The FAA estimates that 235 airplanes

of U.S. registry would be affected by this

proposed AD, that it would take

approximately 6 work hours per

airplane to accomplish the proposed

inspection and installation and that the

average labor rate is $60 per work hour.

Based on these figures, the cost impact

of the proposed AD on U.S. operators is

estimated to be $84,600, or $360 per

airplane.

The cost impact figure discussed

above is based on assumptions that no

operator has yet accomplished any of

the 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

adding the following new airworthiness

directive:

Bombardier, Inc. (Formerly de Havilland,

Inc.): Docket 99-NM–371-AD.

Applicability: Model DHC–8–100, –200,

and –300 series airplanes, having serial

numbers 003 through 528 inclusive and 531;

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 (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 damage of the upper wing

ladder plates, which could result in

displacement of the adjacent channel seals

and consequent reduced lightning strike

protection of the fuel tanks, accomplish the

following:

(a) Within 60 days after the effective date

of this AD, perform a one-time detailed

visual inspection to detect damage (i.e.,

fretting and/or corrosion) of the ladder plates

and access cover areas of the upper surface

of the wings in accordance with paragraph

III.A., III.B., or III.C., as applicable, of the

Accomplishment Instructions of Bombardier

Service Bulletin S.B. 8–57–41, Revision ‘A’,

dated July 28, 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 aids such as mirror,

magnifying lenses, etc. may be used. Surface

cleaning and elaborate access procedures

may be required.’’

(1) If no damage is detected, prior to

further flight, install new 0.103-inch

diameter O-ring seals in accordance with

paragraph III.A., III.B., or III.C., as applicable,

of the Accomplishment Instructions of the

service bulletin.

(2) If any damage is detected that is within

the limits specified in the Structure Repair

Manual (SRM), prior to further flight, repair

the damage in accordance with the SRM, and

install new 0.103-inch diameter O-ring seals

in accordance with paragraph III.A., III.B., or

III.C., as applicable, of the Accomplishment

Instructions of the service bulletin.

(3) If any damage is detected that is outside

the limits specified in the SRM, prior to

further flight, repair in accordance with a

method approved by the Manager, New York

Aircraft Certification Office (ACO), FAA,

Engine and Propeller Directorate, and install

new 0.103–inch diameter O–ring seals.

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, New York

ACO. Operators shall submit their requests

through an appropriate FAA Principal

Maintenance Inspector, who may add

comments and then send it to the Manager,

New York ACO.

Note 3: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the New York 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.

Note 4: The subject of this AD is addressed

in Canadian airworthiness directive CF–99–

20, dated July 20, 1999.

Issued in Renton, Washington, on February

4, 2000.

Donald L. Riggin,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 00–3133 Filed 2–9–00; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98–NM–99–AD]

RIN 2120–AA64

Airworthiness Directives; Airbus Model

A320 Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).