Airworthiness Directives; Airbus Model A300, A310, and A300-600 Series Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-187-AD]

RIN 2120-AA64

Airworthiness Directives; Airbus Model A300, A310, and A300-600

Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing

airworthiness directive (AD), applicable to all Airbus Model A300,

A310, and A300-600 series airplanes, that currently requires performing

a ram air turbine (RAT) extension test; removing and disassembling the

RAT uplock mechanism; performing an inspection to detect corrosion of

the RAT uplock mechanism, and replacement with a new assembly, if

necessary; and cleaning all the parts of the RAT control shaft and its

bearing component parts. This action would require modification of the

RAT unlocking control unit, which would constitute terminating action

for the repetitive tests and inspections. This action also would limit

the applicability of the existing AD. 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 of the RAT uplock pin/shaft and

needle, which could result in failure of the RAT to deploy and

consequent loss of emergency hydraulic power to the flight controls in

the event that power is lost in both engines.

DATES: Comments must be received by September 14, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Transport Airplane Directorate, ANM-114,

Attention: Rules Docket No. 98-NM-187-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 98-NM-187-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.

[[Page 43350]]

98-NM-187-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

On October 20, 1997, the FAA issued AD 97-22-06, amendment 39-10177

(62 FR 55726, October 28, 1997), applicable to all Airbus Model A300,

A310, and A300-600 airplanes, to require performing a ram air turbine

(RAT) extension test; removing and disassembling the RAT uplock

mechanism; performing an inspection to detect corrosion of the RAT

uplock mechanism, and replacement with a new assembly, if necessary;

and cleaning all the parts of the RAT control shaft and its bearing

component parts. That action was prompted by reports indicating that

the RAT did not extend during ground testing, due to corrosion in the

uplock pin/shaft and the needle bearing of the RAT. The requirements of

that AD are intended to detect and correct such corrosion of the RAT,

which could result in failure of the RAT to deploy and consequent loss

of emergency hydraulic power to the flight controls in the event that

power is lost in both engines.

Issuance of New Service Information

The manufacturer has issued Airbus Service Bulletins A300-29-0109

(for Model A300 series airplanes); A310-29-2077 (for Model A310 series

airplanes); and A300-29-6038 (for Model A300-600 series airplanes); all

dated January 27, 1997; which describe procedures for modification of

the RAT unlocking control unit, which would eliminate the need for the

repetitive tests and inspections. In addition, the service bulletins

limit the effectivity to those airplanes on which the modification was

not accomplished during production. Accomplishment of the actions

specified in the service bulletins is intended to adequately address

the identified unsafe condition. The Direction Generale de l'Aviation

Civile (DGAC) approved these service bulletins as optional terminating

action, and issued French airworthiness directive 95-163-182(B)R3,

dated May 7, 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 97-22-06 to

continue to require performing a RAT extension test; removing and

disassembling the RAT uplock mechanism; performing an inspection to

detect corrosion of the RAT uplock mechanism, and replacement with a

new assembly, if necessary; and cleaning all the parts of the RAT

control shaft and its bearing component parts. The proposed AD would

add a requirement to modify the RAT unlocking control unit, which would

constitute terminating action for the repetitive test and inspection

requirements. The proposed AD also would limit the applicability of the

existing AD to those airplanes on which the modification was not

accomplished during production. The actions would be required to be

accomplished in accordance with the service bulletins described

previously.

Differences Between Proposed Rule and Foreign AD

The proposed AD would differ from the parallel French airworthiness

directive in that it would mandate the accomplishment of the

terminating action for the repetitive tests and inspections. The French

airworthiness directive provides for that action as optional.

Mandating the terminating action is based on the FAA's

determination that long-term continued operational safety will be

better assured by modifications or design changes to remove the source

of the problem, rather than by repetitive inspections. Long-term tests

and inspections may not be providing the degree of safety assurance

necessary for the transport airplane fleet. This, coupled with a better

understanding of the human factors associated with numerous continual

inspections, has led the FAA to consider placing less emphasis on

inspections and more emphasis on design improvements. The proposed

modification requirement is in consonance with these conditions.

Cost Impact

There are approximately 126 Model A300, A310, and A300-600 series

airplanes of U.S. registry that would be affected by this proposed AD.

The actions that are currently required by AD 97-22-06 take

approximately 10 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 currently required actions on U.S. operators is

estimated to be $75,600, or $600 per airplane.

The modification that is proposed in this AD action would take

approximately 9 work hours per airplane to accomplish, at an average

labor rate of $60 per work hour. Required parts would cost

approximately $1,972 per airplane. Based on these figures, the cost

impact of the modification proposed by this AD on U.S. operators is

estimated to be $316,512, or $2,512 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 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.''

[[Page 43351]]

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.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by removing amendment 39-10177 (62 FR

55726, October 28, 1997), and by adding a new airworthiness directive

(AD), to read as follows:

Airbus Industrie: Docket 98-NM-187-AD. Supersedes AD 97-22-06,

Amendment 39-10177.

Applicability: Model A300, A310, and A300-600 series airplanes

on which Airbus Modification 11527 has not been accomplished;

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 (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 of the ram air turbine (RAT) uplock pin/

shaft and needle, which could result in failure of the RAT to deploy

and consequent loss of emergency hydraulic power to the flight

controls in the event that power is lost in both engines, accomplish

the following:

Restatement of the Requirements of AD 97-22-06

(a) Within 30 months since the date of manufacture, or within 3

months after December 2, 1997 (the effective date of AD 97-22-06,

amendment 39-10177), whichever occurs later: Accomplish the

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

accordance with Airbus Service Bulletin A300-29-0108, dated April 1,

1996 (for Model A300 series airplanes); A310-29-2076, dated April 1,

1996 (for Model A310 series airplanes); or A300-29-6037, dated April

1, 1996 (for Model A300-600 series airplanes); as applicable.

Thereafter, repeat these actions at intervals not to exceed 30

months.

(1) Perform a RAT extension test on the ground, in accordance

with the procedures specified in the Maintenance Manual.

(2) Disassemble and remove the uplock mechanism of the RAT and

perform a visual inspection of the uplock mechanism to detect

corrosion, in accordance with the applicable service bulletin.

Note 2: For the purposes of this AD, the RAT uplock mechanism

includes both the lever assembly and uplock unit.

(i) If no corrosion is detected: Prior to further flight, clean and

lubricate the uplock mechanism and its associated parts, reinstall the

assembly, and perform a retraction/extension/retraction of the RAT, in

accordance with the applicable service bulletin.

(ii) If any corrosion is detected in any part of the uplock

mechanism, prior to further flight, accomplish either paragraph

(a)(2)(ii)(A) or (a)(2)(ii)(B) of this AD in accordance with the

applicable service bulletin.

(A) Replace the uplock mechanism with a new part and perform a

retraction/extension/retraction of the RAT, in accordance with the

applicable service bulletin. Or

(B) Clean and lubricate the uplock mechanism and its associated

parts. Within 30 days following accomplishment of this cleaning and

lubrication, replace the uplock mechanism with a new part and

perform a retraction/extension/retraction of the RAT.

(b) Initial accomplishment of the actions required by paragraph

(a) of this AD that have been performed in accordance with Airbus

All Operator Telex 29-16, Revision 01, dated January 10, 1996, is

considered acceptable for compliance with the initial RAT extension

test and an initial visual inspection as required by paragraph (a)

of this AD. However, the first repetitive inspection, as required by

paragraph (a) of this AD, must be performed within 30 months after

that RAT extension test and visual inspection were conducted, and

repeated thereafter at intervals not to exceed 30 months.

New Requirements of this AD

(c) Within 30 months after the effective date of this AD, modify

the RAT unlocking control unit in accordance with Airbus Service

Bulletin A300-29-0109 (for Model A300 series airplanes); A310-29-

2077 (for Model A310 series airplanes); or A300-29-6038 (for Model

A300-600 series airplanes); all dated January 27, 1997; as

applicable. Accomplishment of this modification constitutes

terminating action for the repetitive test and inspection

requirements 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, 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.

(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 French

airworthiness directive 95-163-182(B)R3, dated May 7, 1997.

Issued in Renton, Washington, on August 7, 1998.

Darrell M. Pederson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 98-21715 Filed 8-12-98; 8:45 am]

BILLING CODE CODE 4910-13-P