Airworthiness Directives; Airbus Model A330 and A340 Series Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-184-AD]

RIN 2120-AA64

Airworthiness Directives; Airbus Model A330 and A340 Series

Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness

directive (AD) that is applicable to certain Airbus Model A330 and A340

series airplanes. This proposal would require repetitive detailed

visual inspections to detect cracking of the vertical flange of the

inboard Z-stiffeners of the centerline panel of the fuselage belly

fairing; and corrective actions, if necessary. This proposed AD also

provides for optional terminating action for the repetitive

inspections. 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

detect and correct fatigue cracking of the vertical flange of the

inboard Z-stiffeners of the centerline panel of the fuselage belly

fairing, which could result in reduced structural integrity of the

belly fairing.

DATES: Comments must be received by October 12, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

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

Attention: Rules Docket No. 99-NM-184-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 99-NM-184-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-184-AD, 1601 Lind Avenue, SW., Renton, Washington

98055-4056.

Discussion

The Direction Generale de l Aviation Civile (DGAC), which is the

airworthiness authority for France, notified the FAA that an unsafe

condition may exist on certain Airbus Model A330 and A340 series

airplanes. The DGAC advises that during full-scale fatigue testing,

fatigue cracking occurred in one of the inboard Z-stiffeners at the

fitting retaining the centerline panel between the main landing gear

doors. The cracking initiated in the cut-out radius of the vertical

flange and propagated downward. Such fatigue cracking, if not detected

and corrected, could result in reduced structural integrity of the

belly fairing.

Explanation of Relevant Service Information

The manufacturer has issued Airbus Service Bulletins A330-53-3020

(for Model A330 series airplanes) and A340-53-4029 (for Model A340

series airplanes); each dated November 30, 1995. These service

bulletins describe procedures for repetitive detailed visual

inspections to detect cracking of the vertical flange of the inboard Z-

stiffeners of the centerline panel of the fuselage belly fairing; and

corrective actions, if necessary. The detailed visual inspection

includes the left- and right-hand sides of the centerline panel between

the main landing gear doors. The corrective actions reference the

accomplishment of Airbus Service Bulletin A330-53-3019 (for Model A330

series airplanes) or A340-53-4028 (for Model A340 series airplanes);

each dated November 30, 1995. These service bulletins describe

procedures for modification of the vertical flange of the inboard Z-

stiffeners of the centerline panel of the fuselage belly fairing. The

modification involves the installation of a new cut-out of the vertical

flange of the inboard Z-stiffeners; and installation of an external

reinforcement plate (strap), and modification of the assembly (length

of fasteners) between the Z-stiffeners and the belly fairing panel.

Accomplishment of the modification of the vertical flange of the

inboard Z-stiffeners of the centerline panel of the fuselage belly

fairing eliminates the need for the repetitive inspections, provided

that all cracking is eliminated. Accomplishment of the actions

specified in the applicable service bulletins is intended to adequately

address the identified unsafe condition. The DGAC classified Airbus

Service Bulletins A330-53-3020 and A340-53-4029 as mandatory and issued

French airworthiness directives 96-056-029 (B) (for Model A330 series

airplanes), and 96-057-042 (B) (for Model A340 series airplanes); each

dated March 13, 1996; 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

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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, this

proposed AD would require accomplishment of the actions specified in

the service bulletins described previously, except as discussed below.

This proposed AD also would provide for optional terminating action for

the repetitive inspections.

Operators should note that, in consonance with the findings of the

DGAC, the FAA has determined that the repetitive inspections proposed

by this AD can be allowed to continue in lieu of accomplishment of a

terminating action. In making this determination, the FAA considers

that, in this case, long-term continued operational safety will be

adequately assured by accomplishing the repetitive inspections to

detect cracking before it represents a hazard to the airplane.

Differences Between Proposed Rule and Service Bulletin

Unlike the procedures described in Airbus Service Bulletins A330-

53-3020 (for Model A330 series airplanes) and A340-53-4029 (for Model

A340 series airplanes), this proposed AD would not permit further

flight if cracks are detected of the vertical flange of the inboard Z-

stiffeners of the centerline panel of the fuselage belly fairing. The

FAA has determined that, because of the safety implications and

consequences associated with such cracking, any vertical flange of the

inboard Z-stiffener that is found to be cracked must be repaired or

modified to eliminate any cracking, or repaired (for any cracking that

cannot be eliminated), prior to further flight.

Operators also should note that, although the service bulletins

specify that the manufacturer may be contacted for disposition of

certain cracking conditions, this proposal would require the repair of

those conditions to be accomplished in accordance with a method

approved by the FAA.

Cost Impact

None of the airplanes affected by this action are on the U.S.

Register. All airplanes included in the applicability of this proposed

rule currently are operated by non-U.S. operators under foreign

registry; therefore, they are not directly affected by this proposed AD

action. However, the FAA considers that this proposed rule is necessary

to ensure that the unsafe condition is addressed in the event that any

of these subject airplanes are imported and placed on the U.S. Register

in the future.

Should an affected airplane be imported and placed on the U.S.

Register in the future, it would require approximately 1 work hour to

accomplish the proposed inspection, at an average labor rate of $60 per

work hour. Based on these figures, the cost impact of this AD would be

$60 per airplane, per inspection cycle.

Should an operator elect to accomplish the optional terminating

action proposed by this AD, it would require approximately 7 work hours

to accomplish the proposed optional terminating action, at an average

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

approximately $2,350 per airplane. Based on these figures, the cost

impact of the optional terminating action is estimated to $2,770 per

airplane.

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.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new

airworthiness directive:

Airbus Industrie: Docket 99-NM-184-AD.

Applicability: Model A330 and A340 series airplanes; except

those airplanes on which Airbus Modification 42605, or Airbus

Service Bulletin A330-53-3019 (for Model A330 series airplanes) or

A340-53-4028 (for Model A340 series airplanes) has 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 (c) 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 detect and correct fatigue cracking of the vertical flange of

the inboard Z-stiffeners of the centerline panel of the fuselage

belly fairing, which could result in reduced structural integrity of

the belly fairing, accomplish the following:

Repetitive Detailed Visual Inspections

(a) Prior to the accumulation of 5,500 total flight cycles, or

within 500 flight hours after the effective date of this AD,

whichever occurs later, perform a detailed visual inspection to

detect cracking of the vertical flange of the inboard Z-stiffeners

of the centerline panel of the fuselage belly fairing, in accordance

with Airbus Service Bulletin A330-53-3020 (for Model A330 series

airplanes) or A340-53-4029 (for Model A340 series airplanes); each

dated November 30, 1995; as applicable.

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.''

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(1) If no cracking is detected, repeat the inspection thereafter

at intervals not to exceed 5,500 flight cycles, until the

requirements of paragraph (b) of this AD are accomplished.

Corrective Actions

(2) If any cracking is detected during any inspection required

by this AD, prior to further flight, modify the vertical flange of

both inboard Z-stiffeners of the centerline panel of the fuselage

belly fairing and re-inspect the modified area to determine if

cracking has been eliminated, in accordance with Airbus Service

Bulletin A330-53-3019 (for Model A330 series airplanes) or A340-53-

4028 (for Model A340 series airplanes); each dated November 30,

1995; as applicable.

(i) If all cracking is not eliminated after accomplishment of

the modification, prior to further flight, repair in accordance with

a method approved by either the Manager, International Branch, ANM-

116, FAA, Transport Airplane Directorate; or the Direction Generale

de l'Aviation Civile (DGAC) (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.

(ii) If all cracking is eliminated after the accomplishment of

the modification, no further action is required by this AD.

Optional Terminating Action

(b) Modification of the vertical flange of both inboard Z-

stiffeners of the centerline panel of the fuselage belly fairing in

accordance with Airbus Service Bulletin A330-53-3019 (for Model A330

series airplanes) or A340-53-4028 (for Model A340 series airplanes);

each dated November 30, 1995; as applicable constitutes terminating

action for the requirements of this AD.

Alternative Methods of Compliance

(c) 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.

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

(d) 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 French airworthiness

directives 96-056-029 (B) and 96-057-042 (B); each dated March 13,

1996; in order to assure the continued airworthiness of these

airplanes in France.

Issued in Renton, Washington, on September 2, 1999.

Dorenda D. Baker,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 99-23477 Filed 9-9-99; 8:45 am]

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