Airworthiness Directives; Airbus Model A319 and A320 Series Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-NM-92-AD]

RIN 2120-AA64

Airworthiness Directives; Airbus Model A319 and A320 Series

Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Supplemental notice of proposed rulemaking; reopening of

comment period.

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SUMMARY: This document revises an earlier proposed airworthiness

directive (AD), applicable to certain Airbus Model A320 series

airplanes, that would have required repetitive inspections to detect

cracking and delamination of the containers in which the off-wing

emergency evacuation slides are stored, and corrective actions, if

necessary. If cracking and delamination in excess of certain limits are

found, the proposed AD would have required replacement of the slide

with a modified slide, which would have terminated the inspection

requirement. This new action revises the proposed rule by requiring an

additional modification of the slides; accomplishment of both

modifications of the slides would terminate the requirement for

repetitive inspections. This proposal is prompted by issuance of

mandatory continuing airworthiness information by a foreign civil

airworthiness authority. The actions specified by this new proposed AD

are intended to prevent the loss of the escape slides during flight,

which could make the emergency exits located over each wing unusable

and result in damage to the fuselage.

DATES: Comments must be received by November 3, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

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

Attention: Rules Docket No. 96-NM-92-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 96-NM-92-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. 96-NM-92-AD, 1601 Lind Avenue, SW., Renton, Washington

98055-4056.

[[Page 55643]]

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 January 14,

1997 (62 FR 1861). That NPRM would have required repetitive inspections

to detect cracking and delamination of the containers in which the left

and right off-wing emergency evacuation slides are stored, and repair,

if necessary. If cracking and delamination in excess of certain limits

are found, that proposed AD also would have required replacement of the

slide with a modified slide, which would have terminated the

requirement for repetitive inspections; and replacement of the

discrepant container with a serviceable container. That NPRM was

prompted by a report indicating that a slide deployed during flight,

which resulted in the loss of the slide and the container door. That

condition, if not corrected, could make the emergency exits located

over each wing unusable and result in damage to the fuselage.

Actions Since Issuance of Previous Proposal

Since the issuance of that NPRM, the Direction Generale de

l'Aviation Civile (DGAC), which is the airworthiness authority for

France, has advised the FAA that, although repackaging of the slide was

previously thought to be sufficient to prevent loss of container doors

and consequent loss of escape slides, inservice inspections have

revealed that interference may still be present even with correctly

packed slides. Therefore, the DGAC no longer considers that

modification of the slides as described in Airbus Service Bulletin

A320-25-1156, dated June 21, 1995, will eliminate the need for

repetitive inspections of the slides.

Explanation of Relevant Service Information

Airbus has issued Service Bulletin A320-25-1161, Revision 01, dated

February 2, 1999. The inspection procedures described in this service

bulletin are identical to the previous revision. However, this revision

includes Airbus Model A319 series airplanes in the effectivity, adds

references to an additional modification of the offwing escape slides,

and updates certain service bulletin references to later revisions.

Airbus also has issued Service Bulletin A320-25-1156, Revision 01,

dated February 2, 1999, which describes procedures for an additional

modification of the offwing escape slides. The new modification

involves structurally enhancing the container door by replacing

frangible washers with solid ring retainers. The modification also

involves inspecting each slide as described in A320-25-1161, Revision

01, repairing, if necessary, and repacking the slide. Accomplishment of

this modification, in addition to the modification specified in the

original service bulletin, would eliminate the need for the repetitive

inspections of the escape slide containers. The Airbus service bulletin

references Air Cruisers Service Bulletins 004-25-37, Revision 2, dated

May 29, 1996, and 004-25-42, dated September 16, 1996, as additional

sources of service information for accomplishment of the modifications.

Accomplishment of the actions specified in the Airbus service

bulletins is intended to adequately address the identified unsafe

condition. The DGAC classified Airbus Service Bulletin A320-25-1161,

Revision 01, dated February 2, 1999, as mandatory and issued French

airworthiness directive 1999-232-132(B), dated June 2, 1999, in order

to assure the continued airworthiness of these airplanes in France.

Conclusion

This supplemental NPRM proposes to add a requirement for

modification of the slides in accordance with Airbus Service Bulletin

A320-25-1156, Revision 01, dated February 2, 1999, which would

terminate the requirement for repetitive inspections. This supplemental

NPRM would also revise the applicability to add Airbus Model A319

series airplanes, and to exclude airplanes on which the terminating

modification has been accomplished in production or in service. Since

certain of 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.

Differences Between Proposed Rule and French AD

The proposed AD would differ from the parallel French airworthiness

directive in that it would mandate the accomplishment of the

modifications of the offwing escape slides within 5 years, which would

constitute terminating action for the repetitive inspections required

by this AD. 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

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 consistent with these conditions.

Cost Impact

The FAA estimates that 121 airplanes of U.S. registry would be

affected by this proposed AD.

It would take approximately 5 work hours per airplane to accomplish

the proposed inspection, at an average labor rate of $60 per work hour.

Based on these figures, the cost impact of the proposed inspection on

U.S. operators is estimated to be $36,300, or $300 per airplane, per

inspection cycle.

It would take approximately 6 work hours per airplane to accomplish

the proposed modifications, at an average labor rate of $60 per work

hour. Required parts would cost approximately $170 per airplane. Based

on these figures, the cost impact of the proposed modifications on U.S.

operators is estimated to be $64,130, or $530 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,

[[Page 55644]]

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 96-NM-92-AD.

Applicability: Model A319 and A320 series airplanes,

certificated in any category; except airplanes on which Airbus

Modifications 24850 and 25844 have been installed in production, or

on which Airbus Service Bulletin A320-25-1156, Revision 01, dated

February 2, 1999, has been accomplished.

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 the loss of the escape slides during flight, which

could make the emergency exits located over each wing unusable and

result in damage to the fuselage, accomplish the following:

Inspections and Corrective Actions

(a) At the latest of the times specified in paragraphs (a)(1),

(a)(2), and (a)(3) of this AD, as applicable: Perform a detailed

visual inspection to detect cracking and delamination of each off-

wing escape slide container, including the container door, in

accordance with Airbus Service Bulletin A320-25-1161, Revision 01,

dated February 2, 1999. Repeat the inspection thereafter at

intervals not to exceed 18 months, until accomplishment of the

actions required by paragraph (d) of this AD.

(1) Within 500 flight hours after the effective date of this AD.

(2) Within 18 months after the last inspection in accordance

with Airbus All Operator Telex 25-09, dated January 2, 1995, or

Revision 1, dated February 16, 1995; or Airbus Service Bulletin

A320-25-1161, dated June 21, 1995; if accomplished prior to the

effective date of this AD.

(3) Within 18 months after modification of the offwing escape

slides in accordance with Airbus Service Bulletin A320-25-1156,

dated June 21, 1995; if accomplished prior to the effective date of

this AD.

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.''

(b) If any crack or delamination is found during any inspection

required by paragraph (a) of this AD that does not exceed the limits

specified in Airbus Service Bulletin A320-25-1161, Revision 01,

dated February 2, 1999: Prior to further flight, repair the crack or

delamination in accordance with the service bulletin, and continue

inspecting in accordance with paragraph (a) of this AD.

(c) If any crack or delamination is found during any inspection

required by paragraph (a) of this AD that exceeds the limits

specified in Airbus Service Bulletin A320-25-1161, Revision 01,

dated February 2, 1999: Prior to further flight, replace the

discrepant container with a serviceable container in accordance with

the service bulletin, and continue inspecting in accordance with

paragraph (a) of this AD.

Terminating Modification

(d) Within 5 years after the effective date of this AD, modify

the offwing escape slides (i.e., modifications, inspection, repair,

and repacking) in accordance with Airbus Service Bulletin A320-25-

1156, Revision 01, dated February 2, 1999. Modification of the

escape slides constitutes terminating action for the repetitive

inspections required by paragraph (a) of this AD.

Note 3: Airbus Service Bulletin A320-25-1156, Revision 01, dated

February 2, 1999, references Air Cruisers Service Bulletins 004-25-

37, Revision 2, dated May 29, 1996, and 004-25-42, dated September

16, 1996, as additional sources of service information for

accomplishment of the modification of the offwing escape slides.

Alternative Methods of Compliance

(e) 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 4: 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

(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 5: The subject of this AD is addressed in French

airworthiness directive 1999-232-132(B), dated June 2, 1999.

Issued in Renton, Washington, on October 7, 1999.

D.L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 99-26871 Filed 10-13-99; 8:45 am]

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