23690 Federal Register / Vol. 63, No. 83 /Thursday, April 30, 1998 / Proposed Rules

To prevent a high pressure fuel leak, which

could result in an engine nacelle fire and

damage to the aircraft, accomplish the

following:

(a) For R–R Viper Mk. 521, and 522 series

engines, perform a one-time inspection of the

barometric flow control unit (BFCU)

augmentor and bypass valve joint washer for

joint washer integrity, and replace, if

necessary, with serviceable parts, in

accordance with R–R Service Bulletins (SBs)

Nos. 73–A120 and 73–A121, as applicable,

dated November 1997, as follows:

(1) For engines with less than 200 hours

time in service (TIS) since new, overhaul, or

repair of the BFCU, inspect within 2 months,

or 100 hours TIS after the effective date of

this AD, whichever occurs first.

(2) For engines with 200 or more hours TIS

since new, overhaul, or repair of the BFCU,

inspect at the next engine removal after the

effective date of this AD.

(b) For R–R Viper Mk. 526 series engines,

perform a one-time inspection of the

barometric flow control unit (BFCU) augment

or and bypass valve joint washer for joint

washer integrity, and replace, if necessary,

with serviceable parts, in accordance with R–

R Service Bulletins (SBs) Nos. 73–A68 and

73–A69, as applicable, dated November 1997,

as follows:

(1) For engines with less than 200 hours

time in service (TIS) since new, overhaul, or

repair of the BFCU, inspect within 2 months,

or 100 hours TIS after the effective date of

this AD, whichever occurs first.

(2) For engines with 200 or more hours TIS

since new, overhaul, or repair of the BFCU,

inspect at the next engine removal after the

effective date of this AD.

(c) For R–R Viper Mk. 601 series engines,

perform a one-time inspection of the BFCU

augmentor and bypass valve joint washer for

joint washer integrity, and replace, if

necessary, with serviceable parts, in

accordance with R–R SBs Nos. 73–A35 and

73–A36, as applicable, dated November 1997,

as follows:

(1) For engines with less than 200 hours

TIS since new, overhaul, or repair of the

BFCU, inspect within 2 months, or 100 hours

TIS after the effective date of this AD,

whichever occurs first.

(2) For engines with 200 or more hours TIS

since new, overhaul, or repair of the BFCU,

inspect at the next engine removal after the

effective date of this AD.

(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, Engine

Certification Office. Operators shall submit

their requests through an appropriate FAA

Principal Maintenance Inspector, who may

add comments and then send it to the

Manager, Engine Certification Office.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this airworthiness directive,

if any, may be obtained from the Engine

Certification Office.

(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 aircraft to

a location where the requirements of this AD

can be accomplished.

Issued in Burlington, Massachusetts, on

April 23, 1998.

Jay J. Pardee,

Manager, Engine and Propeller Directorate,

Aircraft Certification Service.

[FR Doc. 98–11436 Filed 4–29–98; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97–NM–310–AD]

RIN 2120–AA64

Airworthiness Directives; Airbus Model

A310 and 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 A310 and A300–600

series airplanes, that currently requires,

among other things, repetitive

inspections to ensure correct

synchronization of the hydraulic control

valves of the trimmable horizontal

stabilizer (THS) actuator; replacement of

the horizontal stabilizer actuator motors

with new or serviceable motors and

resynchronization of the valves, or

adjustment of the synchronization, if

necessary; and a functional test of the

THS. This proposed AD would add a

requirement to replace the hydraulic

motor of the THS with an improved

motor, which would constitute

terminating action for the repetitive

inspections. This proposal also would

expand the applicability to include

additional airplanes. This proposal is

prompted by the issuance of mandatory

continuing airworthiness information by

a foreign civil airworthiness authority.

The actions specified by the proposed

AD are intended to prevent

desynchronization of the hydraulic

control valves, which could result in

runaway of the horizontal stabilizer to

its full up or down position, subsequent

reduced maneuvering capability, and

potential pitch upset.

DATES: Comments must be received by

June 1, 1998.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 97-NM–

310-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

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 97-NM–310-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.

97-NM–310-AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

On January 12, 1996, the FAA issued

AD 96–01–52, amendment 39–9491 (61
Federal Register / Vol. 63, No. 83 /Thursday, April 30, 1998 / Proposed Rules 23691

FR 2697, January 29, 1996), applicable

to certain Airbus Model A310 and

A300–600 series airplanes. That AD

requires, among other things, repetitive

inspections to ensure correct

synchronization of the hydraulic control

valves of the trimmable horizontal

stabilizer (THS) actuator; replacement of

the horizontal stabilizer actuator motors

with new or serviceable motors and

resynchronization of the valves, or

adjustment of the synchronization, if

necessary; and a functional test of the

THS. That action was prompted by a

report of desynchronization of the

hydraulic control valves that direct fluid

to the horizontal stabilizer actuator

motors, which resulted in

uncommanded movement of the THS.

The actions specified by that AD are

intended to prevent such

desynchronization, which could lead to

runaway of the horizontal stabilizer to

its full up or down position, subsequent

reduced maneuvering capability, and

potential pitch upset.

Actions Since Issuance of Previous Rule

In the preamble to AD 96–01–52, the

FAA specified that the actions required

by that AD were considered ‘‘interim

action.’’ The FAA indicated that it

might consider further rulemaking

action once a final action was identified.

The manufacturer now has developed a

modification of the hydraulic motor of

the THS that includes an improved

camplate retention device and pin. The

FAA has determined that further

rulemaking action is indeed necessary

in order to address the unsafe condition

and ensure the continued safe operation

of the affected airplanes; this proposed

AD follows from that determination.

Explanation of Relevant Service

Information

Airbus has issued Service Bulletins

A310–27–2081 (for Model A310 series

airplanes) and A300–27–6035 (for

Model A300–600 series airplanes), both

dated November 26, 1996. These service

bulletins describe procedures for the

installation of a modified hydraulic

motor that includes an improved

camplate retention device and pin. The

effectivity of these service bulletins

includes the airplanes affected by the

service bulletins that are required by the

existing AD, and includes additional

airplanes. Accomplishment of the

actions specified in the service bulletins

is intended to adequately address the

identified unsafe condition. The

Direction Ge ́ne ́rale de l’Aviation Civile

(DGAC), which is the airworthiness

authority for France, classified these

service bulletins as mandatory and

issued French airworthiness directive

97–081–217(B), dated March 12, 1997,

in order to assure the continued

airworthiness of these airplanes in

France.

FAA’s Conclusions

These airplane models are

manufactured in France 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 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 96–01–52 to continue to

require, among other things, repetitive

inspections to ensure correct

synchronization of the hydraulic control

valves of the THS actuator; replacement

of the motors of the horizontal stabilizer

actuator with new or serviceable motors

and resynchronization of the valves, or

adjustment of the synchronization, if

necessary; and a functional test of the

THS. This proposed AD would add a

requirement to replace the THS actuator

hydraulic motor with an improved

motor. Accomplishment of this

replacement would constitute

terminating action for the repetitive

inspection requirements. This proposed

AD also would expand the applicability

of the existing AD to include additional

airplanes. The replacement of the motor

with an improved motor would be

required to be accomplished in

accordance with the service bulletins

described previously.

Difference Between the Proposed Rule

and the French AD

Operators should note that, although

the parallel French airworthiness

directive recommends accomplishing

the modification by August 31, 1998

(providing a compliance time of

approximately 17 months), the FAA has

determined that a 17-month compliance

time would not address the identified

unsafe condition in a timely manner. In

developing an appropriate compliance

time for this AD, the FAA considered

not only the recommendations by the

DGAC, but the degree of urgency

associated with addressing the subject

unsafe condition, the average utilization

of the affected fleet, and the time

necessary to accomplish the

modification. In light of all of these

factors, the FAA finds a 12-month

compliance time for accomplishment of

the modification to be warranted.

Cost Impact

There are approximately 88 airplanes

of U.S. registry that would be affected

by this proposed AD.

The inspection currently required by

AD 96–01–52, and retained in this

proposed AD, takes approximately 1

work hour per airplane to accomplish,

at an average labor rate of $60 per work

hour. Based on these figures, the cost

impact of the requirements of the

existing AD on U.S. operators is

estimated to be $5,280, or $60 per

airplane, per inspection cycle.

The new actions that are proposed in

this AD action would take

approximately 4 work hours per

airplane to accomplish, at an average

labor rate of $60 per work hour.

Required parts would be provided by

the manufacturer at no cost to the

operators. Based on these figures, the

cost impact of the new actions proposed

by this AD on U.S. operators is

estimated to be $21,120, or $240 per

airplane.

The cost impact figures discussed

above are 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 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
23692 Federal Register / Vol. 63, No. 83 /Thursday, April 30, 1998 / Proposed Rules

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 39–9491 (61 FR

2697, anuary 29, 1996), and by adding

a new airworthiness directive (AD), to

read as follows:

Airbus: Docket 97–NM–310–AD.

Supersedes AD 96–01–52, Amendment 39–

9491.

Applicability: Model A310 and A300–600

series airplanes on which Airbus

Modification 11607 has not been installed,

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

owner/operator must request approval for an

alternative method of compliance in

accordance with paragraph (e) 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 desynchronization of the

hydraulic control valves, which could result

in runaway of the horizontal stabilizer to its

full up or down position, subsequent reduced

maneuvering capability, and potential pitch

upset, accomplish the following:

RESTATEMENT OF REQUIREMENTS OF

AD 96–01–52:

(a) Within 12 days after February 5, 1996

(the effective date of AD 96–01–52,

amendment 39–9491), perform an inspection

to ensure correct synchronization of the

hydraulic control valves of the trimmable

horizontal stabilizer (THS) actuator, in

accordance with paragraph 4.2.2.1 of Airbus

All Operators Telex (AOT) 27–21, Revision 1,

dated January 5, 1996.

(1) If the actuator is synchronized

correctly, prior to further flight, perform a

functional test of the THS in accordance with

paragraph 4.2.2.1 of the AOT. Thereafter,

repeat the inspection required by paragraph

(a) of this AD at intervals not to exceed 500

hours time-in-service.

(2) If the actuator is desynchronized

slightly, as specified in the AOT, prior to

further flight, adjust the synchronization, and

perform a functional test of the THS, in

accordance with paragraph 4.2.2.2 of the

AOT. Thereafter, repeat the inspection

required by paragraph (a) of this AD at

intervals not to exceed 500 hours time-inservice.

(3) If the actuator is desynchronized

significantly, as specified in the AOT, prior

to further flight, accomplish either paragraph

(a)(3)(i) or (a)(3)(ii) of this AD. Prior to further

flight following the accomplishment of either

of those paragraphs, adjust the

synchronization, and perform a functional

test of the THS, in accordance with

paragraph 4.2.2.3 of the AOT. Thereafter,

repeat the inspection required by paragraph

(a) of this AD at intervals not to exceed 500

hours time-in-service.

(i) Remove and replace the hydraulic

motors of the horizontal stabilizer actuator

(HSA) with new or serviceable motors in

accordance with procedures specified in the

Airplane Maintenance Manual. Or

(ii) Remove the hydraulic motors of the

HSA and perform the various follow-on

actions specified in paragraph 4.2.2.4 of the

AOT, in accordance with that paragraph.

(The follow-on actions include checking the

motors and the cam seats, assembling the

motors, and metal stamping the modification

plate of the motors.) If any discrepancy is

found during the check, prior to further

flight, repair in accordance with paragraph

4.2.2.4 of the AOT.

(b) For airplanes on which any

maintenance action relating to a hydraulic

motor or a hydraulic valve block of the HSA

has occurred since the airplane was new:

Within 12 days after February 5, 1996,

accomplish either paragraph (b)(1) or (b)(2) of

this AD.

(1) Replace both hydraulic motors of the

HSA with new or serviceable motors in

accordance with the procedures specified in

the Airplane Maintenance Manual. Adjust

the synchronization, and perform a

functional test of the THS in accordance with

paragraph 4.2.2.3 of Airbus AOT 27–21,

Revision 1, dated January 5, 1996. Thereafter,

perform the repetitive inspections required

by paragraph (a) of this AD at intervals not

to exceed 500 hours time-in-service. Or

(2) Remove the hydraulic motors of the

HSA and perform the various follow-on

actions specified in paragraph 4.2.2.4 of the

AOT, in accordance with that paragraph of

the AOT. Adjust the synchronization, and

perform a functional test of the THS in

accordance with paragraph 4.2.2.3 of the

AOT. (The follow-on actions include

checking the motors and the cam seats,

assembling the motors, and metal stamping

the modification plate of the motors.) If any

discrepancy is found during the check, prior

to further flight, repair in accordance with

paragraph 4.2.2.4 of the AOT. Thereafter,

perform the repetitive inspections required

by paragraph (a) of this AD at intervals not

to exceed 500 hours time-in-service.

NEW REQUIREMENTS OF THIS AD:

(c) Within 1 year after the effective date of

this AD, replace the hydraulic motors of the

THS actuator with improved motors, in

accordance with Airbus Service Bulletin

A310–27–2081 (for Model A310 series

airplanes) or A300–27–6035 (for Model

A300–600 series airplanes), both dated

November 26, 1996, as applicable.

Accomplishment of this action constitutes

terminating action for the repetitive

inspection requirements of this AD.

(d) As of the effective date of this AD, no

person shall install on any airplane a THS

actuator having part number 47142–201/–

203.

(e)(1) 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.

(e)(2) Alternative methods of compliance,

approved previously in accordance with AD

96–01–52, amendment 39–9491, are

approved as alternative methods of

compliance with paragraphs (a) and (b) of

this AD.

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.

(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 97–081–

217(B), dated March 12, 1997.

Issued in Renton, Washington, on April 23,

1998.

Gary L. Killion,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 98–11435 Filed 4–29–98; 8:45 am]

BILLING CODE 4910–13–U