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–
18998 Federal Register / Vol. 61, No. 84 / Tuesday, April 30, 1996 / Proposed Rules

36–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

Boeing Commercial Airplane Group,

P.O. Box 3707, Seattle, Washington

98124–2207. This information may be

examined at the FAA, Transport

Airplane Directorate, 1601 Lind

Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

Kenneth W. Frey, Aerospace Engineer,

Systems and Equipment Branch, ANM–

130S, FAA, Seattle Aircraft Certification

Office, 1601 Lind Avenue, SW., Renton,

Washington; telephone (206) 227–2673;

fax (206) 227–1181.

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–36–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.

96–NM–36–AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

The FAA received two reports

indicating that the hydraulic system A

and the standby hydraulic system have

failed on Model 737 series airplanes

during flight. During subsequent

emergency landings, these airplanes

departed the end of the runway and

sustained severe damage. On one of

these airplanes, both actuator attach

lugs on the support fittings of the No. 1

Krueger flap actuator were severed

completely. The actuator separated from

the front spar, and the adjacent

hydraulic lines were severed. On

another airplane, the No. 3 Krueger flap

actuator separated from the fitting, and

the hydraulic lines to the actuator were

severed. Subsequently, the hydraulic

fuse did not close sufficiently to prevent

the loss of hydraulic fluid from the

system. Results of a laboratory

examination of the fuse indicated that

corrosion existed on the magnesium

piston of the fuse, which contributed to

the failure of the fuse. Failure of the

hydraulic fuse, if not corrected, could

result in the failure of one or more

hydraulic systems and, consequently,

could result in reduced controllability

of the airplane.

Hydraulic fuses are installed to

prevent failure of the hydraulic system

in the event of breakage of the hydraulic

lines to leading edge devices such as the

actuators. These fuses also preserve the

flight control systems following a major

failure such as an uncontained engine

failure, and minimize the fire hazard in

the event of a hydraulic line failure in

the brake system. The FAA has

determined that hydraulic fuses having

magnesium pistons are installed on

Model 737–100 and –200 series

airplanes as well as Model 747–100,

–200, –300, and –SP series airplanes.

Therefore, the FAA finds that all of

these airplane models are subject to the

unsafe condition identified in this

proposal.

Explanation of Relevant Service

Information

The FAA has reviewed and approved

Boeing Service Letter 737–SL–29–21,

dated December 16, 1982 (for Model 737

series airplanes). This service letter

describes procedures for replacement of

the existing Waterman hydraulic fuse

assemblies with modified assemblies

having pistons made from aluminum.

Accomplishment of this replacement

will reduce the susceptibility of the

piston to corrosion damage. The Boeing

service letter references Imperial

Clevite, Inc., Service Bulletins G838–

80–4, G838–80–5, and G838–80–6, all

dated April 15, 1982, as additional

sources of service information for

accomplishment of the replacement.

The FAA also has reviewed and

approved Boeing Service Letter 747–SL–

32–19, dated January 16, 1980 (for

Model 747 series airplanes). This

service letter describes procedures for

an inspection of the existing Waterman

Type II hydraulic fuse assemblies for

corrosion of the piston, and replacement

of Type II hydraulic fuse assemblies

with improved Type I fuse assemblies.

Waterman Type II fuses require reverse

flow to reset, while Type I fuses have a

manual reset lever. The improved fuses

are manufactured by Pneudraulics, Inc.

Explanation of Requirements of

Proposed Rule

Since an unsafe condition has been

identified that is likely to exist or

develop on other products of this same

type design, the proposed AD would

require replacement of Waterman

hydraulic fuse assemblies with modified

assemblies. The actions would be

required to be accomplished in

accordance with the service letters

described previously.

Affected operators of Model 737 series

airplanes should note that, although

Boeing Service Letter 737–SL–29–21

recommends that subsequent periodic

tests of the modified fuses be

accomplished, the FAA has not

included such a requirement in this

proposed AD. The FAA has determined

that procedures required by operators’

individual maintenance programs will

adequately address periodic inspections

of the new fuse assemblies.

The FAA is considering the issuance

of a separate rulemaking action to

address fatigue and stress corrosion of

the support fitting on the Krueger flap

actuator for Model 737–100 and –200

series airplanes. (The Krueger flap

actuator installed on Model 747 series

airplanes has a different part number

from that installed on Model 737 series

airplanes.)

Cost Impact

There are approximately 1,145 Model

737 series airplanes and 727 Model 747

series airplanes of the affected design in

the worldwide fleet.

The FAA estimates that 421 Model

737 series airplanes of U.S. registry

would be affected by this proposed AD,

that it would take approximately 16

work hours per airplane (8 fuses per

airplane; 2 work hours per fuse) to

accomplish the proposed actions, and

that the average labor rate is $60 per

work hour. Required parts that are

modified by the vendor would be

provided at no cost to operators. Based

on these figures, the cost impact of the
Federal Register / Vol. 61, No. 84 / Tuesday, April 30, 1996 / Proposed Rules 18999

proposed AD on U.S. operators is

estimated to be $404,160, or $960 per

airplane.

The FAA estimates that 208 Model

747 series airplanes of U.S. registry

would be affected by this proposed AD,

that it would take approximately 48

work hours per airplane (24 fuses per

airplane; 2 work hours per fuse) to

accomplish the proposed actions, and

that the average labor rate is $60 per

work hour. Required parts that are

modified by the vendor would be

provided at no cost to operators. Based

on these figures, the cost impact of the

proposed AD on U.S. operators is

estimated to be $599,040, or $2,880 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,

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 USC 106(g), 40113, 44701.

§ 39.13 [Amended]

2. Section 39.13 is amended by

adding the following new airworthiness

directive:

Boeing: Docket 96–NM–36–AD.

Applicability: Model 737–100 and –200

series airplanes, as identified in Boeing

Service Letter 737–SL–29–21, dated

December 16, 1982; and Model 747–100,

–200, –300, and –SP series airplanes, as

identified in Boeing Service Letter 747–SL–

32–19, dated January 16, 1980; 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 failure of the hydraulic fuse,

which could result in the failure of one or

more hydraulic systems and resultant

reduced controllability of the airplane,

accomplish the following:

(a) For Model 737–100 and –200 series

airplanes: Within 3,000 flight hours after the

effective date of this AD, replace Waterman

hydraulic fuse assemblies, having Waterman

part number (P/N) G838–8–40, G838–8–60,

or G838–8–160, with modified assemblies

having P/N G8381–8–40, G8381–8–60, or

G8381–8–160, respectively; or with a

Pneudraulics fuse specified in Boeing Service

Letter 737–SL–29–21, dated December 16,

1982. Accomplish the replacement in

accordance with the service letter.

Note 2: The Boeing service letter references

Imperial Clevite, Inc., Service Bulletins

G838–80–4, G838–80–5, and G838–80–6, all

dated April 15, 1982, as additional sources of

service information for accomplishment of

the replacement.

(b) For Model 747–100, –200, –300, and

–SP series airplanes: Within 3,000 flight

hours after the effective date of this AD,

replace Waterman hydraulic fuse assemblies,

having Waterman P/N G905–120, with

Pneudraulics assemblies having Pneudraulics

P/N 6105, in accordance with Boeing Service

Letter 747–SL–32–19, dated January 16,

1980.

(c) As of the effective date of this AD, no

person shall install on any airplane

Waterman hydraulic fuse assemblies having

Waterman P/N G838–8–40, G838–8–60,

G838–8–160, or G905–120 on any airplane.

(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, Seattle

Aircraft Certification Office (ACO), 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, Seattle ACO.

Note 3: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Seattle ACO.

(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.

Issued in Renton, Washington, on April 24,

1996.

S.R. Miller,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 96–10622 Filed 4–29–96; 8:45 am]

BILLING CODE 4910–13–U

14 CFR Part 71

[Airspace Docket No. 96–AEA–04]

Proposed Establishment of Class E

Airspace; Mitchellville, MD

AGENCY: Federal Aviation

Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking.

SUMMARY: This proposed rule would

establish Class E Airspace at

Mitchellville, MD. A Very High

Frequency Omni-Directional Range

(VOR) standard instrument approach

procedure (SIAP) has been developed

for Runway (RWY) 36 at Freeway

Airport, Mitchellville, MD. The

intended effect of this proposal is to

provide adequate controlled airspace for

Instrument Flight Rules (IFR) operations

to the airport. The area would be

depicted on aeronautical charts for pilot

reference.

DATES: Comments must be received on

or before May 30, 1996.

ADDRESSES: Send comments on the

proposed rule in triplicate to: Manager,

System Management Branch, AEA-530,

Docket No. 96–AEA–04 FAA Eastern

Region, Federal Building #111 John F.

Kennedy Int’l Airport, Jamaica, NY

11430.

The official docket may be examined

in the Office of the Assistant Chief

Counsel, AEA–7, FAA Eastern Region,

Federal Building #111, John F. Kennedy

International Airport, Jamaica, NY

11430.