Airworthiness Directives; Airbus Model A320 Series Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 93-NM-63-AD]

Airworthiness Directives; Airbus Model 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 revising the Limitations Section of

the Airplane Flight Manual (AFM) to prohibit the airplane from extended

overwater operations. That proposal was prompted by a report that,

during an emergency evacuation demonstration, the lanyard connecting

the survival kit to the slide/raft became entangled on the girt bar

indicator mechanism, and subsequently prevented an exit door from

opening fully to a locked position. This action revises the proposed

rule by deleting the previously proposed AFM limitation; and requiring

either the removal of the girt bar visual indicator brackets on

passenger exit doors or modification of the lanyard. The actions

specified by this proposed AD are intended to prevent the lanyard from

becoming entangled and interfering with proper opening of the exit

door, a situation which could impede the successful evacuation of

passengers through the door during an overwater operation where

ditching is required.

DATES: Comments must be received by May 25, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Transport Airplane Directorate, ANM-103,

Attention: Rules Docket No. 93-NM-63-AD, 1601 Lind Avenue SW., Renton,

Washington 98055-4056. Comments may be inspected at this location

between 9 a.m. and 3 p.m., Monday through Friday, except Federal

holidays. -

This information may be examined at the FAA, Transport Airplane

Directorate, 1601 Lind Avenue SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Stephen Slotte, Aerospace Engineer,

Standardization Branch, ANM-113, FAA, Transport Airplane Directorate,

1601 Lind Avenue SW., Renton, Washington 98055-4056; telephone (206)

227-2797; fax (206) 227-1320.

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 93-NM-63-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. 93-NM-63-AD, 1601 Lind Avenue, SW., Renton, Washington

98055-4056.

Discussion

A proposal to amend part 39 of the Federal Aviation Regulations to

add an airworthiness directive (AD), applicable to all Airbus Model

A320 series airplanes, was published as a notice of proposed rulemaking

(NPRM) in the Federal Register on July 27, 1993 (58 FR 40077). That

NPRM would have required revising the Limitations Section of the FAA-

approved Airplane Flight Manual (AFM) to prohibit the airplane from

extended overwater operations. That action also would have provided for

an optional terminating action of modification of the lanyard that

attaches the overwater survival kit to the slide/raft; once

accomplished, the AFM limitation could be removed.

NPRM was prompted by a report that, during an emergency evacuation

demonstration, the subject lanyard became entangled on the girt bar

indicator mechanism, and subsequently prevented an exit door from

opening fully to a locked position. That condition, if not corrected,

could impede the successful evacuation of passengers through the door

during an overwater operation where ditching is required. -

Since the issuance of that NPRM, the FAA has reconsidered its

position on certain of the proposed requirements, based on the comments

received in response to the notice. -

One commenter, Airbus Industrie (Airbus), questions the

justification for the proposed rule, and requests that the FAA withdraw

it . Airbus contends that, according to the international bilateral

airworthiness agreements, the responsibility to determine the existence

and extent of an unsafe condition with respect to any reported incident

lies within the jurisdiction of the primary authority, in this case,

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

airworthiness authority for France. Airbus states that the DGAC made a

decision not to issue a French airworthiness directive to mandate a

modification of the airplane design because (1) the slide was correctly

deployed during the incident upon which this proposed rule is based;

and (2) although the door did not go to the fully-open position during

that incident, it did not interfere with the passenger flow during

evacuation. Airbus also states that the door will remain in the not-

fully-open position until it is pushed to the fully-open position by

the assisting cylinder, which is maintained pressurized until the door

reaches the fully-open and locked position. During the incident, the

door did not initially go to the fully-open position because the

overwater survival kit lanyard was caught by the visual indicator

bracket and became entangled between the door and the fuselage. When

the crew untangled the lanyard, the door went into the fully-opened and

locked position. -

The FAA does not concur with the commenter's suggestion to withdraw

the proposal. While the United States and France observe the provisions

of the bilateral airworthiness agreement, it remains the responsibility

of the FAA to monitor and maintain the continuing airworthiness of

U.S.-type certificated and -registered airplanes. The bilateral

airworthiness agreements do not restrict the FAA from issuing AD's

based upon its own finding of an unsafe condition, regardless of the

decision made by another airworthiness authority relative to the same

subject. The FAA has examined the analyses of the evacuation

demonstration, has reviewed all other available data, and has

determined that an unsafe condition exists with regard to problem of

the lanyard becoming entangled on the girt bar indicator mechanism and

preventing the exit door from opening fully to a locked position.

Therefore, the FAA has determined that AD action is necessary for

airplanes of this type design that are certificated for operation in

the United States. -

One commenter requests that the applicability of the proposed rule

be limited to only those Model A320 series airplanes that are equipped

with slide/raft evacuation systems eligible for overwater operations.

The commenter contends that the scenario for the occurrence of the

addressed unsafe condition would not apply to those airplanes without

the slide/raft evacuation systems; therefore, they should be exempt

from the proposed rule. The FAA concurs and has revised the

applicability of this supplemental NPRM accordingly. -

Two commenters request that the proposal be revised to include the

installation of Modification 23605, described in Airbus Service

Bulletin A320-25-1109, dated April 20, 1993, as an acceptable

modification that would permit the removal of the proposed limitation

in the AFM (prohibiting extended overwater operations). This

modification entails replacing the existing girt bar indicator bracket

with a red arrow placard on the slide/raft decorative covers. The FAA

does not concur totally with the commenters' request. The FAA has

evaluated the referenced modification and has found that, while removal

of the brackets will prevent possible interference between the

overwater survival kit lanyard and the slide/raft decorative cover, the

placards do not provide for an acceptable means of girt bar position

indication. -

The FAA has reviewed the current design of the visual girt bar

position indicator brackets (plates) and finds that, as designed and

installed, these brackets contribute to the problem of lanyard

entanglement that leads to the unsafe condition addressed by this AD.

In light of this, the FAA has revised this proposed rule to require

that, in lieu of modifying the lanyard, operators may remove the girt

bar visual indicator brackets from all doors that are equipped with

them. (The girt bar position/arming indicator in the cockpit, however,

would be unaffected by this action; it would remain as a source to

obtain positive indication of the position of the girt bar.) The FAA

considers that this proposed action will be as effective in addressing

the unsafe condition and as timely to accomplish as the modificatin of

the lanyard. Additionally, since removal of the brackets or

modificaiton of the lanyard will eliminate the problem of entanglement

of the lanyard and the subsequent problems of opening the exit door

properly, the FAA has deleted the previously proposed requirement that

would have prohibited extended overwater operation of the affected

airplanes.

This is considered interim action. Airbus Industrie has advised the

FAA that it is developing an alternative method of girt bar position

indication that will not entail a design feature that would contribute

to the addressed problem of lanyard entanglement. Once this

modification is developed, approved, and available, the FAA may

consider further rulemaking. -

Since the change described above expands 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. -

The FAA estimates that 59 Model A320 airplanes of U.S. registry

would be affected by this proposed AD.

Accomplishment of the removal of the girt bar visual indicator

brackets would take approximately 1 work hour per airplane, at an

average labor rate of $55 per work hour. Based on these figures, the

total cost impact of this proposed removal action on U.S. operators who

elect to accomplish it is estimated to be $55 per airplane.

The time necessary to accomplish the modification of the lanyard

may vary from operator to operator, depending upon the design submitted

for approval by the FAA. However, the FAA estimates that a typical

modification would require an average of 2 work hours to accomplish, at

an average labor rate of $55 per work hour. Based on these figures, the

total cost impact of this proposed modification action on U.S.

operators who elect to accomplish it is estimated to be $110 per

airplane.

Based on the figures discussed above, the total cost impact of this

proposed AD on U.S. operators is estimated to be between $3,245 and

$6,490. This total cost impact figure is 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. -

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 14

CFR part 39 of the Federal Aviation Regulations as follows:

PART 39--AIRWORTHINESS DIRECTIVES -

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C.

106(g); and 14 CFR 11.89.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new

airworthiness directive:

Airbus Industrie: Docket 93-NM-63-AD.

Applicability: Model A320 series airplanes equipped with slide/

raft evacuation systems, certificated in any category. -

Compliance: Required as indicated, unless accomplished

previously.

To prevent the lanyard from becoming entangled on the girt bar

indicator mechanism, if passengers are required to utilize the exit

door during extended overwater operations where ditching may be

required, accomplish the following: -

(a) Within 90 days after the effective date of this AD,

accomplish the requirements of either paragraph (a)(1) or (a)(2) of

this AD:

(1) Remove the girt bar visual indicator brackets (plates) from

all passenger exit doors that are so equipped. Or

(2) Modify the lanyard that attaches the survival kit to the

slide/raft so that it does not become entangled on the girt bar

indicator mechanism, in accordance with a method approved by the

Manager, Standardization Branch, ANM-113, FAA, Transport Airplane

Directorate.-

(b) 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,

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: 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

Secs. 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 April 19, 1994.

S.R. Miller,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-9870 Filed 4-25-94; 8:45 am]

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