Federal Register / Vol. 65, No. 3 / Wednesday, January 5, 2000 / Proposed Rules 395

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99–NM–51–AD]

RIN 2120–AA64

Airworthiness Directives; Saab Model

SAAB SF340A and SAAB 340B 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 Saab Model SAAB SF340A and

SAAB 340B series airplanes. This

proposal would require a one-time

inspection to detect corrosion and

scratches on the bearing housing

surfaces of the support assembly on the

main landing gear (MLG), and corrective

actions, if necessary. 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 corrosion in

the inboard and outboard bearing

housings of the MLG support assembly,

which could result in fatigue cracks in

the support assembly and lead to failure

of the MLG.

DATES: Comments must be received by

February 4, 2000.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 99–NM–

51–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

Saab Aircraft AB, SAAB Aircraft

Product Support, S–581.88, Linko ̈ping,

Sweden. 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

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–51–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–51–AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

The Luftfartsverket (LFV), which is

the airworthiness authority for Sweden,

notified the FAA that an unsafe

condition may exist on certain Saab

Model SAAB SF340A and SAAB 340B

series airplanes. The LFV advises that,

during replacement of landing gear

support assembly bearings, pitting

corrosion has been found in the

outboard and inboard bearing housings.

The corrosion is believed to be caused

by intrusion of moisture between the

bearing and its housing surface. Such

corrosion, if not corrected, could result

in fatigue cracks in the support

assembly and lead to failure of the main

landing gear (MLG).

Explanation of Relevant Service

Information

Saab has issued Service Bulletin 340–

57–036, dated October 20, 1999, which

describes a one-time visual inspection

to detect corrosion and scratches on the

bearing housing surfaces of the support

assembly on the MLG. The service

bulletin also describes procedures for

corrosion removal, an eddy current

inspection, and repair if corrosion or

scratches are found. Accomplishment of

the actions specified in the service

bulletin is intended to adequately

address the identified unsafe condition.

The LFV classified this service bulletin

as mandatory and issued Swedish

airworthiness directive No. 1–146, dated

October 20, 1999, in order to ensure the

continued airworthiness of these

airplanes in Sweden.

FAA’s Conclusions

These airplane models are

manufactured in Sweden and are 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 LFV has

kept the FAA informed of the situation

described above. The FAA has

examined the findings of the LFV,

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 described below.

Differences Between Proposed AD and

Service Bulletin

Operators should note that, although

the service bulletin specifies that the

manufacturer may be 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 or the LFV.

396 Federal Register / Vol. 65, No. 3 / Wednesday, January 5, 2000 / Proposed Rules

Cost Impact

The FAA estimates that 291 airplanes

of U.S. registry would be affected by this

proposed AD, that it would take

approximately 2 work hours per

airplane to accomplish the proposed

inspection, 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 $34,920, or $120 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 substantial direct effects

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,

in accordance with Executive Order

12612, it is determined that this

proposal would not have sufficient

federalism implications to warrant the

preparation of a Federalism Assessment.

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:

SAAB Aircraft AB: Docket 99–NM–51–AD.

Applicability: Model SAAB SF340A, serial

numbers 004 through 159 inclusive; and

SAAB 340B series airplanes, serial numbers

160 through 444 inclusive; 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 (d) 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 corrosion in the inboard and

outboard bearing housings of the support

assembly of the main landing gear (MLG),

which could result in fatigue cracks in the

support assembly and lead to failure of the

MLG, accomplish the following:

(a) At the applicable time specified in

paragraph (a)(1), (a)(2), (a)(3), or (a)(4) of this

AD: Perform a one-time general visual

inspection of the eight bearing housing

surfaces of the MLG to detect corrosion or

scratches, in accordance with Saab Service

Bulletin 340–57–036, dated October 20, 1999.

(1) For airplanes with 32,000 or more total

flight cycles as of the effective date of this

AD, the inspection is to be performed within

4,000 flight cycles after the effective date of

this AD.

(2) For airplanes with 24,000 or more and

fewer than 32,000 total flight cycles as of the

effective date of this AD, the inspection is to

be performed within 6,000 flight cycles after

the effective date of this AD.

(3) For airplanes with 12,000 or more and

fewer than 24,000 total flight cycles as of the

effective date of this AD, the inspection is to

be performed prior to the accumulation of

24,000 total flight cycles, or within 6,000

flight cycles after the effective date of this

AD, whichever occurs later.

(4) For airplanes with fewer than 12,000

total flight cycles as of the effective date of

this AD, the inspection is to be performed

prior to the accumulation of 12,000 total

flight cycles, or within 6,000 flight cycles

after the effective date of this AD, whichever

occurs later.

Note 2: For the purposes of this AD, a

general visual inspection is defined as: ‘‘A

visual examination of an interior or exterior

area, installation, or assembly to detect

obvious damage, failure, or irregularity. This

level of inspection is made under normally

available lighting conditions such as

daylight, hangar lighting, flashlight, or droplight, and may require removal or opening of

access panels or doors. Stands, ladders, or

platforms may be required to gain proximity

to the area being checked.’’

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

this AD: If, during the inspection required by

paragraph (a) of this AD, any corrosion or

scratch is detected that is within the limits

specified in Saab Service Bulletin 340–57–

036, dated October 20, 1999, prior to further

flight, perform corrective actions (including

rework, an eddy current inspection, and

repair) in accordance with steps 2.B. and 2.C.

of the Accomplishment Instructions of the

service bulletin.

(c) If, during any inspection required by

this AD, a discrepancy is detected for which

the service bulletin specifies to contact Saab

for appropriate action [including any crack or

any corrosion or scratch that exceeds 1.1 mm

(0.043 in) after applicable rework has been

performed as required by paragraph (b) of

this AD]: Prior to further flight, repair in

accordance with a method approved by the

Manager, International Branch, ANM–116,

Transport Airplane Directorate; or the

Luftfartsverket (LFV) (or its delegated agent).

For a repair method to be approved by the

Manager, International Branch, ANM–116, as

required by this paragraph, the Manager’s

approval letter must specifically reference

this AD.

Alternative Methods of Compliance

(d) 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 3: 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

(e) 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 Swedish airworthiness directive No. 1–

146, dated October 20, 1999.

Issued in Renton, Washington, on

December 29, 1999.

D. L. Riggin,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 00–138 Filed 1–4–00; 8:45 am]

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