11388 Federal Register / Vol. 62, No. 48 / Wednesday, March 12, 1997 / Proposed Rules

Standardization Branch, ANM–113,

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, Standardization Branch,

ANM–113.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Standardization Branch,

ANM–113.

(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.

Issued in Renton, Washington, on March 5,

1997.

Darrell M. Pederson,

Acting Manager,

Transport Airplane Directorate,

Aircraft Certification Service.

[FR Doc. 97–6087 Filed 3–11–97; 8:45 am]

BILLING CODE 4910–13–U

14 CFR Part 39

[Docket No. 95–NM–216–AD]

RIN 2120–AA64

Airworthiness Directives; Airbus Model

A320 Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Supplemental notice of

proposed rulemaking; reopening of

comment period.

SUMMARY: This document revises an

earlier proposed airworthiness directive

(AD), which would have superseded an

existing AD that is applicable to certain

Airbus Model A320 series airplanes.

The existing AD currently requires

inspections to detect cracking of certain

floor beams and side box-beams, and

repair of cracks. It also requires

modification of the pressure floor. The

previously proposed action would have

added a requirement to install a new,

improved modification for the pressure

floor. This action revises the previously

proposed rule by adding a one-time

inspection to verify proper clearance

between the fasteners of the

reinforcement bracket and the bellcrank

of the free-fall extension system of the

main landing gear (MLG) and its

associated tie rod attachment nut. It also

would require that a different new,

improved modification be installed. The

actions specified by this proposed AD

are intended to prevent reduced

structural integrity of the fuselage,

restricted operation of the MLG free-fall

system and, consequently, reduced

ability to use the MLG during an

emergency.

DATES: Comments must be received by

March 31, 1997.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–103,

Attention: Rules Docket No. 95-NM–

216-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: Tim

Backman, Aerospace Engineer,

Standardization Branch, ANM–113,

FAA, Transport Airplane Directorate,

1601 Lind Avenue, SW., Renton,

Washington 98055–4056; telephone

(206) 227–2797; fax (206) 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 95-NM–216-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–103, Attention: Rules Docket No.

95-NM–216-AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

A proposal to amend part 39 of the

Federal Aviation Regulations (14 CFR

part 39) to add an airworthiness

directive (AD), applicable to certain

Airbus Model A320 series airplanes,

was published as a notice of proposed

rulemaking (NPRM) in the Federal

Register on April 15, 1996 (61 FR

16414). That NPRM would have

superseded AD 93–14–04, amendment

39–8628 (58 FR 39440, July 23, 1993),

to continue to require a one-time eddy

current and detailed visual inspections

to detect cracks of various areas around

the fastener/bolt holes of the pressure

floor. That NPRM also would have

added a requirement to install a new,

improved modification requirement for

the pressure floor at section 15 of the

fuselage. That NPRM was prompted by

the results of a full-scale fatigue test,

which indicated that fatigue cracking

can occur in those areas. Such fatigue

cracking, if not detected and corrected

in a timely manner, could result in

reduced structural integrity of the

fuselage.

Actions Since Issuance of Originally

Proposed NPRM

Since the issuance of that NPRM, the

Direction G•n•rale de l’Aviation Civile

(DGAC), which is the airworthiness

authority for France, notified the FAA

that an additional unsafe condition may

exist on Airbus Model A320 series

airplanes that were modified in

accordance with Airbus Service Bulletin

A320–53–1023, Revision 3, dated March

18, 1994. That modification was

considered to be terminating action for

the repetitive inspection requirements

of AD 93–14–04. The DGAC advises

that, following accomplishment of the

subject modification, it received reports

indicating that interference could occur

between the fasteners of the

reinforcement bracket and the bellcrank

of the free-fall extension system of the

main landing gear (MLG) and its

associated tie rod attachment nut. This

condition, if not corrected, could restrict

operation of the free-fall system of the

MLG and, consequently, result in

reduced ability to use the MLG during

an emergency.
Federal Register / Vol. 62, No. 48 / Wednesday, March 12, 1997 / Proposed Rules 11389

Description of Revised Service

Information

Airbus has issued Revision 7 of

Service Bulletin A320–53–1023, dated

November 3, 1995, which describes

procedures for installation of a new,

improved modification of the pressure

floor at section 15 of the fuselage. This

revision differs from Revision 3 of the

service bulletin in the following two

aspects:

1. It includes updated installation

procedures for the fasteners located

adjacent to the bell crank lever of the

free-fall extension system of the MLG;

and

2. It includes additional procedures

for reworking the attachment bracket

located above the pressure diaphragm.

Accomplishment of this modification

would eliminate the need for the onetime eddy current and detailed visual

inspections. Installation of the new,

improved modification will positively

address the unsafe condition identified

as reduced structural integrity of the

fuselage, and restricted operation of the

MLG free fall system.

Airbus also has issued All Operators

Telex (AOT) 53–08, Revision 01, dated

January 15, 1996, which concerns only

certain airplanes. The service bulletin

describes procedures for performing a

one-time inspection to verify proper

clearance between the fasteners of the

reinforcement bracket and the bellcrank

of the free-fall extension system of the

MLG and its associated tie rod

attachment nut. The AOT also describes

procedures for reinstalling the

reinforcement bracket fasteners, or,

under certain conditions, reworking the

bellcrank lever and fasteners, if

necessary.

The DGAC classified the Airbus

service bulletin and AOT as mandatory

and issued French airworthiness

directive 96–053–077(B), dated March

13, 1996, in order to assure the

continued airworthiness of these

airplanes in France.

Explanation of Changes Made to

Proposal

Based on this new information, the

FAA has determined that the previously

issued proposal must be revised in order

to adequately address the unsafe

condition presented by interference

problems associated with

accomplishment of the procedures

contained in Airbus Service Bulletin

A320–53–1023, up to and including

Revision 6, dated September 4, 1995.

Accordingly, the FAA has added a

new paragraph (c) to this supplemental

NPRM, which would require the

accomplishment of the procedures

specified in Airbus AOT 53–08,

Revision 01, dated January 15, 1996,

described previously. In addition,

paragraph (c) of the supplemental

NPRM also would include a

requirement to accomplish the

modification specified in Revision 7 of

Airbus Service Bulletin A320–53–1023,

described previously.

The FAA also has revised paragraph

(c) of the originally-proposed NPRM

[designated as paragraph (d) in this

supplemental NPRM] to reference

Revision 7 of Airbus Service Bulletin

A320–53–1023 as the appropriate

source of service information for

modification of the pressure floor.

Since these changes expand the scope

of the originally proposed rule, the FAA

has determined that it is necessary to

reopen the comment period to provide

additional opportunity for public

comment.

Cost Impact

There are approximately 24 Airbus

Model A320 series airplanes of U.S.

registry that would be affected by this

proposed AD.

The inspections that are currently

required by AD 93–14–04 take

approximately 37 work hours per

airplane to accomplish, at an average

labor rate of $60 per work hour. Based

on these figures, the cost impact of the

currently required inspections on U.S.

operators is estimated to be $53,280, or

$2,220 per airplane.

The new inspection that is proposed

by this AD action would take

approximately 11 work hours per

airplane to accomplish, at an average

labor rate of $60 per work hour. Based

on these figures, the cost impact of the

new inspection on U.S. operators is

estimated to be $15,840, or $660 per

airplane.

The new modification that is

proposed by this AD action would take

approximately 142 work hours per

airplane to accomplish, at an average

labor rate of $60 per work hour.

Required parts will be supplied by the

manufacturer at no cost to the operators.

Based on these figures, the cost impact

of the modification on U.S. operators is

estimated to be $204,480, or $8,520 per

airplane.

The cost impact figures discussed

above are 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

removing amendment 39–8628 (58 FR

39440, July 23, 1993), and by adding a

new airworthiness directive (AD) to

read as follows:

Airbus Industrie: Docket 95-NM–216-AD.

Supersedes AD 93–14–04, amendment

39–8628.

Applicability: Model A320 series airplanes,

manufacturer’s serial numbers 002 through

008 inclusive, 010 through 078 inclusive, and

080 through 107 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

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
11390 Federal Register / Vol. 62, No. 48 / Wednesday, March 12, 1997 / Proposed Rules

owner/operator must request approval for an

alternative method of compliance in

accordance with paragraph (f) 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 reduced structural integrity of

the fuselage, restricted operation of the main

landing gear (MLG) free-fall system, and,

consequently, reduced ability to use the MLG

during an emergency, accomplish the

following:

(a) Prior to the accumulation of 12,000 total

landings, or within 6 months after August 23,

1993 (the effective date of AD 93–14–04,

amendment 39–8628), whichever occurs

later, accomplish the requirements of

paragraphs (a)(1) and (a)(2) of this AD, in

accordance with Airbus Industrie Service

Bulletin A320–53–1024, dated September 23,

1992, or Revision 1, dated March 31, 1994.

As of the effective date of this new AD, only

Revision 1 of this service bulletin shall be

used.

(1) Conduct an eddy current inspection to

detect cracking around the fastener/bolt holes

at the top horizontal flange of the floor beams

and side box-beams, at the two sides of the

pressure floor, and at the vertical integral

stiffener of the side box-beams; and

(2) Conduct a detailed visual inspection to

detect cracking around the fastener/bolt holes

at the fillet radius and riveted area of the top

outboard flange of the side box-beam, and at

the flange-corner radius of the slanted

inboard flange of the side box-beam and

fittings.

(b) If any crack is detected during the

inspections required by paragraph (a) of this

AD, prior to further flight, repair the crack in

accordance with a method approved by the

Manager, Standardization Branch, ANM–113,

FAA, Transport Airplane Directorate.

(c) For airplanes on which the modification

specified in Airbus Service Bulletin A320–

53–1023, dated September 23, 1992, as

amended by Service Bulletin Change Notice

0A, dated January 20, 1993; Revision 1, dated

March 23, 1993; Revision 2, dated October

22, 1993; Revision 3, dated March 18, 1994;

Revision 4, dated September 30, 1994;

Revision 5, dated February 28, 1995; or

Revision 6, dated September 4, 1995; has

been accomplished: Accomplish paragraphs

(c)(1) and (c)(2) of this AD.

(1) Prior to the accumulation of 1,000

landings after the effective date of this AD,

perform a one-time inspection to verify

proper clearance between the fasteners of the

reinforcement bracket and the bellcrank of

the free-fall extension system of the MLG and

its associated tie rod attachment nut, in

accordance with Airbus All Operators Telex

(AOT) 53–08, Revision 01, dated January 15,

1996.

(i) If the minimum clearance is greater than

3 mm (0.118 inch) and no evidence of

interference is detected, within 60 months

following accomplishment of the inspection

required by paragraph (c)(1) of this AD,

reinstall the reinforcement bracket fasteners

in accordance with Airbus Service Bulletin

A320–53–1023, Revision 7, dated November

3, 1995.

(ii) If the minimum clearance is 3 mm

(0.118 inch) or less, and no evidence of

interference is detected, within 18 months

following accomplishment of the inspection

required by paragraph (c)(1) of this AD,

reinstall the reinforcement bracket fasteners

in accordance with Airbus Service Bulletin

A320–53–1023, Revision 7, dated November

3, 1995.

(iii) If any interference is detected, prior to

further flight, accomplish either paragraph

(c)(1)(iii)(A) or (c)(1)(iii)(B) of this AD.

(A) Reinstall the reinforcement bracket

fasteners in accordance with Airbus Service

Bulletin A320–53–1023, Revision 7, dated

November 3, 1995; or

(B) Rework the bellcrank lever and

fasteners in accordance with Airbus AOT 53–

08, Revision 01, dated January 15, 1996.

Within 60 months following accomplishment

of the rework, reinstall the reinforcement

bracket fasteners in accordance with Airbus

Service Bulletin A320–53–1023, Revision 7,

dated November 3, 1995.

(2) Prior to the accumulation of 24,000

total landings, or 6 months after the effective

date of this AD, whichever occurs later,

modify the pressure floor at section 15 of the

fuselage in accordance with Airbus Service

Bulletin A320–53–1023, Revision 7, dated

November 3, 1995. Accomplishment of the

modification terminates the requirements of

this AD.

(d) For airplanes on which the

modification specified in Airbus Service

Bulletin A320–53–1023, dated September 23,

1992, as amended by Service Bulletin Change

Notice 0A, dated January 20, 1993; Revision

1, dated March 23, 1993; Revision 2, dated

October 22, 1993; Revision 3, dated March

18, 1994; Revision 4, dated September 30,

1994; Revision 5, dated February 28, 1995; or

Revision 6, dated September 4, 1995; has not

been accomplished: Prior to the

accumulation of 18,000 total landings, or

within 6 months after the effective date of

this AD, whichever occurs later, modify the

pressure floor at section 15 of the fuselage in

accordance with Airbus Service Bulletin

A320–53–1023, Revision 7, dated November

3, 1995. Accomplishment of the modification

terminates the requirements of this AD.

(e) Accomplishment of the modification of

the pressure floor at section 15 of the fuselage

in accordance with Airbus Service Bulletin

A320–53–1023, Revision 7, dated November

3, 1995, constitutes terminating action for the

requirements of this AD.

(f) 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,

Standardization Branch, ANM–113.

Operators shall submit their requests through

an appropriate FAA Principal Maintenance

Inspector, who may add comments and then

send it to the Manager, Standardization

Branch, ANM–113.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Standardization Branch,

ANM–113.

(g) 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.

Issued in Renton, Washington, on March 5,

1997.

Darrell M. Pederson,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 97–6085 Filed 3–11–97; 8:45 am]

BILLING CODE 4910–13–U

14 CFR Part 39

[Docket No. 96–NM–219–AD]

RIN 2120–AA64

Airworthiness Directives; Dornier

Model 328–100 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 Dornier Model 328–100 series

airplanes. This proposal would require

modifying the main landing gear (MLG)

bay areas by installing additional slush

protection covers in those areas. This

proposal is prompted by the

identification of a problem during flight

test analysis, which indicated that slush

can accumulate in the MLG bay areas.

The actions specified by the proposed

AD are intended to prevent the

accumulation of slush in the MLG bay

areas, which could freeze and interfere

with the landing gear or render it

inoperative.

DATES: Comments must be received by

April 21, 1997.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–103,

Attention: Rules Docket No. 96–NM–

219-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

Dornier Luftfahrt GmbH, P.O. Box 1103,

D–82230 Wessling, Germany. This

information may be examined at the

FAA, Transport Airplane Directorate,

1601 Lind Avenue, SW., Renton,

Washington.

FOR FURTHER INFORMATION CONTACT:

Connie Beane, Aerospace Engineer,