This section of the FEDERAL REGISTER

contains notices to the public of the proposed

issuance of rules and regulations. The

purpose of these notices is to give interested

persons an opportunity to participate in the

rule making prior to the adoption of the final

rules.

Proposed Rules Federal Register

18995

Vol. 61, No. 84

Tuesday, April 30, 1996

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95–NM–263–AD]

RIN 2120–AA64

Airworthiness Directives; Airbus Model

A300 B2 and B4 Series Airplanes,

Excluding Model 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 A300 B2 and B4 series

airplanes, that currently requires

repetitive visual inspections to detect

cracks in the forward intermediate

section skin at frame 30A where it joins

stringer 30, and repair, if necessary.

This action would add eddy current

inspection(s) to detect cracks of the

outer skin of the fuselage, which would

terminate the repetitive detailed visual

inspections. This action also would

require repair of any cracked area and

modification of the structure at certain

frames. This proposal is prompted by

in-service experience which has

identified fatigue cracks in this area.

The actions specified by the proposed

AD are intended to prevent fatigue

cracking, which could result in rapid

decompression of the airplane.

DATES: Comments must be received by

June 10, 1996.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–103,

Attention: Rules Docket No. 95–NM–

263–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: Tim

Backman, Aerospace Engineer,

Standardization Branch, ANM–113,

FAA, Transport Airplane Directorate,

1601 Lind Avenue, SW., Renton,

Washington 98055–4056; telephone

(206) 227–2797; fax (206) 227–1149.

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 95–NM–263–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.

95–NM–263–AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

On May 15, 1990, the FAA issued AD

90–11–09, amendment 39–6611 (55 FR

21185, May 23, 1990), applicable to

certain Airbus Model A300 B2 and B4

series airplanes, to require repetitive

visual inspections to detect cracks in the

forward intermediate section skin at

frame 30A where it joins stringer 30,

and repair, if necessary. That action was

prompted by in-service experience

which identified fatigue cracks in this

area. The requirements of that AD are

intended to prevent rapid

decompression of the airplane, as a

result of the problems associated with

fatigue cracking.

In the preamble to that AD, the FAA

indicated that the actions required by

that AD were considered ‘‘interim

action’’ and that further rulemaking

action was being considered. The FAA

now has determined that further

rulemaking action is indeed necessary,

and this proposed AD follows from that

determination.

Explanation of New Service

Information

Since the issuance of AD 90–11–09,

Airbus has issued Service Bulletin

A300–53–283, Revision 2, dated March

17, 1994. The service bulletin describes

procedures for eddy current

inspection(s) to detect cracks of the

outer skin of the fuselage at frames 28A

and 30A above stringer 30, which would

eliminate the need for the repetitive

detailed visual inspections. The service

bulletin also describes procedures for

repairing the cracked area with a filler

and doubler installation. In addition,

the service bulletin permits further

flight, under certain conditions, with

outer skin that is cracked within certain

limits.

Airbus has also issued Service

Bulletin A300–53–285, Revision 1,

dated November 22, 1993, which

describes procedures for modification of

the structure at frames 28A and 30A

between stringers 27 and 30 (left- and

right-hand). The modification involves

cutting the frames and installing strips,

fillers, couplings, sections, sheets, and

angles at the subject area.

Accomplishment of the modification

will eliminate possible cracking in the

outer skin of the fuselage at frames 28A

and 30A, and would positively address

the unsafe condition identified as rapid
18996 Federal Register / Vol. 61, No. 84 / Tuesday, April 30, 1996 / Proposed Rules

decompression of the airplane due to

fatigue cracking.

The DGAC has approved these service

bulletin and issued French

airworthiness directive 90–093–

110(B)R1, dated September 30, 1990, in

order to assure the continued

airworthiness of these airplanes in

France.

FAA’s Conclusions

This airplane model is manufactured

in France and is 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 90–11–09 to continue to

require repetitive detailed visual

inspections to detect cracks of the

forward intermediate section skin of the

fuselage at the junction of frame 30A

and stringer 30.

However, this proposal would add a

requirement to accomplish eddy current

inspections to detect cracks of the outer

skin of the fuselage at frames 28A and

30A above stringer 30. This inspection

action would constitute terminating

action for the repetitive detailed visual

inspections.

The proposed AD also would require

repair of any cracked area, and

modification of the structure at frames

28A and 30A between stringer 27 and

30 (left- and right-hand).

The actions would be required to be

accomplished in accordance with the

service bulletins described previously.

Differences Between Service

Information and Proposed Rule

Operators should note that, unlike the

procedures described in Airbus Service

Bulletin A300–53–283, this proposed

AD would not permit further flight with

cracking detected in the outer skin

within certain limits under certain

conditions. The FAA has determined

that, due to the safety implications and

consequences associated with such

cracking, the subject outer skin that is

found to be cracked must be repaired.

Operators should also note that the

proposed AD would differ from Airbus

Service Bulletin A300–53–283 in that it

would require the initial eddy current

inspection to be accomplished prior to

the accumulation of 14,100 total

landings or 22,000 flight hours after the

effective date of this AD, whichever

occurs first. (The service bulletin

recommends that the limited inspection

be conducted prior to the accumulation

of 18,000 flight or 24,000 flight hours,

whichever occurs first.) In developing

an appropriate compliance time for this

action, the FAA considered not only the

degree of urgency associated with

addressing the subject unsafe condition,

but the susceptibility of the outer skin

of the fuselage to fatigue cracking,

which could result in rapid

decompression of the airplane. The FAA

has also received reports of fatigue

cracking on affected airplanes that had

accumulated as few as 14,100 total flight

cycles. In consideration of these items,

the FAA finds that the initial eddy

current inspection conducted at the

proposed compliance time stated

previously will better ensure that any

detrimental effect associated with

fatigue cracking will be identified and

corrected prior to the time that it could

adversely affect the outer skin of the

fuselage.

Furthermore, the FAA has determined

that long term continued operational

safety will be better assured by 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 in

consonance with these conditions.

Cost Impact

There are approximately 24 Airbus

Model A300 B2 and B4 series airplanes,

excluding Model A300–600 series

airplanes, of U.S. registry would be

affected by this proposed AD.

The detailed visual inspections that

are currently required by AD 90–11–09

take 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 on U.S.

operators of the detailed visual

inspections currently required is

estimated to be $1,440, or $60 per

airplane, per inspection cycle.

The eddy current inspection that is

proposed in this new AD action would

take 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 on U.S.

operators of the proposed eddy current

inspection requirements of this AD is

estimated to be $1,440, or $60 per

airplane, per inspection cycle.

The modification that is proposed in

this new AD action would take

approximately 270 work hours per

airplane to accomplish, at an average

labor rate of $60 per work hour.

Required parts would cost

approximately $7,200 per airplane.

Based on these figures, the cost impact

on U.S. operators of the proposed

modification requirements of this AD is

estimated to be $561,600, or $23,400 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.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation

safety, Safety.
Federal Register / Vol. 61, No. 84 / Tuesday, April 30, 1996 / Proposed Rules 18997

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 USC 106(g), 40113, 44701.

§ 39.13 [Amended]

2. Section 39.13 is amended by

removing amendment 39–6611 (55 FR

21185, May 23, 1990), and by adding a

new airworthiness directive (AD), to

read as follows:

Airbus Industrie: Docket 95–NM–263–AD.

Supersedes AD 90–11–09, Amendment

39–6611.

Applicability: Model A300 B2 and B4

series airplanes, certificated in any category.

Note 1: This AD applies to each airplane

identified in the preceding applicability

provision, regardless of whether it has been

modified, altered, or repaired in the area

subject to the requirements of this AD. For

airplanes that have been otherwise 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 (f) 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.

Note 2: Airbus Model A300–600 series

airplane are not subject to this AD.

To prevent fatigue cracking, which could

result in rapid decompression of the airplane,

accomplish the following:

(a) For airplanes on which Airbus All

Operators Telex (AOT) 53/90/01, dated April

12, 1990 has been accomplished: Prior to the

accumulation of 18,000 total landings or

24,000 total hours time-in-service, whichever

occurs first, or within 100 landings after June

11, 1990 (the effective date of AD 90–11–09,

amendment 39–6611), whichever occurs

later, perform a detailed visual inspection to

detect cracks of the forward intermediate

section skin of the fuselage at the junction of

frame 30A and stringer 30, in accordance

with Airbus All Operators Telex 53/90/01,

dated April 12, 1990.

(1) If no cracks are detected, repeat the

detailed visual inspection thereafter at

intervals not to exceed 2,000 landings until

the requirements of paragraph (b) of this AD

are accomplished.

(2) If any crack is detected, prior to further

flight, repair it in accordance with the AOT.

After any crack is repaired, prior to the

accumulation of 15,000 total landings or

20,000 total hours time-in-service, whichever

occurs first, repeat the detailed visual

inspection until the requirements of

paragraph (b) of this AD are accomplished.

(b) For all airplanes: Perform an eddy

current inspection to detect cracks of the

outer skin of the fuselage at frames 28A and

30A above stringer 30, in accordance with

Airbus Service Bulletin A300–53–283,

Revision 2, dated March 17, 1994, at the time

specified in either paragraph (b)(1) or (b)(2)

of this AD, as applicable. Accomplishment of

the eddy current inspection terminates the

repetitive visual inspection requirements of

paragraph (a) of this AD.

(1) For airplanes on which the

requirements of paragraph (a) of this AD have

been initiated: Perform the eddy current

inspection prior to the accumulation of 2,000

landings since the last inspection performed

in accordance with paragraph (a) of this AD,

or within 100 landings after the effective date

of this AD, whichever occurs later.

(2) For airplanes other than those

identified in paragraph (b)(1) of this AD:

Perform the eddy current inspection at the

later of the times specified in paragraph

(b)(2)(i) or (b)(2)(ii):

(i) Prior to the accumulation of 14,100 total

landings or 22,000 total flight hours after the

effective date of this AD, whichever occurs

first; or

(ii) Within 100 landings after the effective

date of this AD.

(c) If no crack is detected during the eddy

current inspection required by paragraph (b)

of this AD, repeat the eddy current

inspection thereafter at intervals not to

exceed 3,000 landings.

(d) If any crack is detected during any eddy

current inspection required by this AD, prior

to further flight, repair it in accordance with

Airbus All Operators Telex 53/90/01, dated

April 12, 1990, or Airbus Service Bulletin

A300–53–283, Revision 2, dated March 17,

1994. After accomplishing the repair, within

15,000 landings or 20,000 flight hours after

repair, whichever occurs first, modify the

structure at frames 28A and 30A between

stringers 27 and 30 (left- and right-hand), in

accordance with Airbus Service Bulletin

A300–53–285, Revision 1, dated November

22, 1993. Accomplishment of this

reinforcement constitutes terminating action

for this AD.

(e) Except for airplanes on which the repair

required by paragraph (d) of this AD has been

accomplished: Modify the structure at frames

28A and 30A between stringers 27 and 30

(left- and right-hand), in accordance with

Airbus Service Bulletin A300–53–285,

Revision 1, dated November 22, 1993, at the

later of the times specified in paragraphs

(e)(1) or (e)(2) of this AD. Accomplishment of

this modification constitutes terminating

action for the eddy current inspection

requirements of paragraph (c) of this AD.

(1) Prior to the accumulation of 25,000

total landings or 40,000 total flight hours,

whichever occurs first.

(2) Within 1,000 landings after the effective

date of this AD.

(f) 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 3: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Standardization Branch,

ANM–113.

(g) 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.

Issued in Renton, Washington, on April 24,

1996.

S.R. Miller,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 96–10625 Filed 4–29–96; 8:45 am]

BILLING CODE 4910–13–U

14 CFR Part 39

[Docket No. 96–NM–36–AD]

RIN 2120–AA64

Airworthiness Directives; Boeing

Model 737–100 and –200 Series

Airplanes, and Model 747–100, –200,

–300, and –SP Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes the

adoption of a new airworthiness

directive (AD) that is applicable to

certain Boeing Model 737 and 747 series

airplanes. This proposal would require

replacement of Waterman hydraulic

fuse assemblies with modified

assemblies. This proposal is prompted

by reports of failure of hydraulic system

A and the standby system due to

corrosion on the magnesium piston of

the hydraulic fuse and consequent

failure of the fuse to close sufficiently to

prevent the loss of hydraulic fluid from

the system. The actions specified by the

proposed AD are intended to prevent

such failure of the fuse, which could

result in the failure of one or more

hydraulic systems and resultant reduced

controllability of the airplane.

DATES: Comments must be received by

June 10, 1996.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–103,

Attention: Rules Docket No. 96–NM–