Federal Register / Vol. 63, No. 149 /Tuesday, August 4, 1998 / Proposed Rules 41481

§ 39.13 [Amended]

2. Section 39.13 is amended by

adding the following new airworthiness

directive:

McDonnell Douglas: Docket 98–NM–197–

AD.

Applicability: Model DC–10 series

airplanes and KC–10 (military) airplanes, as

listed in McDonnell Douglas Alert Service

Bulletin DC10–55A028, dated April 27, 1998;

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 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 prevent fatigue cracking of the rear spar

cap of the horizontal stabilizer, which could

result in reduced structural integrity of the

horizontal stabilizer, and consequent reduced

controllability of the airplane, accomplish

the following:

(a) Prior to the accumulation of 18,000 total

landings, or within 1,500 landings after the

effective date of this AD, whichever occurs

later: Perform a penetrant inspection or a

high frequency eddy current inspection to

detect fatigue cracking of the rear spar cap of

the horizontal stabilizer, in accordance with

McDonnell Douglas Alert Service Bulletin

DC10–55A028, dated April 27, 1998.

(1) If no cracking is detected, repeat the

inspection thereafter at intervals not to

exceed 2,200 landings until accomplishment

of the requirements of paragraph (b) of this

AD.

(2) If any cracking is detected, prior to

further flight, repair in accordance with the

alert service bulletin. Repeat the inspection

thereafter at intervals not to exceed 2,200

landings until accomplishment of the

requirements of paragraph (b) of this AD.

(b) Within 5 years after the effective date

of this AD, perform a penetrant inspection or

a high frequency eddy current inspection to

detect fatigue cracking of the rear spar cap of

the horizontal stabilizer, in accordance with

McDonnell Douglas Alert Service Bulletin

DC10–55A028, dated April 27, 1998.

(1) If no cracking is detected, prior to

further flight, perform the preventive

modification of the rear spar cap of the

horizontal stabilizer, in accordance with the

alert service bulletin. Accomplishment of

this modification constitutes terminating

action for the requirements of this AD.

(2) If any cracking is detected, prior to

further flight, repair, and perform the

preventive modification of the rear spar cap

of the horizontal stabilizer, in accordance

with the alert service bulletin.

Accomplishment of the modification

constitutes terminating action for the

requirements of this AD.

(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, Los

Angeles 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, Los Angeles ACO.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Los Angeles ACO.

(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.

Issued in Renton, Washington, on July 27,

1998.

S.R. Miller,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 98–20678 Filed 8–3–98; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97–NM–241–AD]

RIN 2120–AA64

Airworthiness Directives; Boeing

Model 767–200, –300, and –300F 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 767–200, –300,

and –300F series airplanes. This

proposal would require replacement of

the hydraulic reducer fitting in the

return port of the alternate brake

selector valve with a new restrictor

fitting. This proposal is prompted by a

report indicating that a brake housing

had fractured due to high loads

associated with brake vibration during

landing gear retraction, which allowed

the torque rod to swing free. The actions

specified by the proposed AD are

intended to prevent failure of the brake

housing in the torque rod region, which

could reduce the braking capability of

the airplane and/or prevent the

extension of a main landing gear by any

method.

DATES: Comments must be received by

September 18, 1998.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 97–NM–

241–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:

David Herron, Aerospace Engineer,

Systems and Equipment Branch, ANM–

130S, FAA, Transport Airplane

Directorate, Seattle Aircraft Certification

Office, 1601 Lind Avenue, SW., Renton,

Washington 98055–4056; telephone

(425) 227–2672; fax (425) 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 97–NM–241–AD.’’ The

postcard will be date stamped and

returned to the commenter.
41482 Federal Register / Vol. 63, No. 149 /Tuesday, August 4, 1998 / Proposed Rules

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.

97–NM–241–AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

The FAA has received several reports

of brake vibration during landing gear

retraction on Boeing Model 767 series

airplanes, including one report

indicating that a brake housing had

fractured during landing gear retraction,

allowing the torque rod to swing free.

The unrestrained torque rod caused

minor damage to components located in

the wheel well. Failure of the brake

housing would result in loss of one of

the eight brakes installed on a main

landing gear. Furthermore, the

unrestrained torque rod could jam in the

wheel well, which could damage

components located in the wheel well

and/or prevent the extension of a main

landing gear. Failure of the brake

housing has been attributed to high

loads associated with brake vibration

during landing gear retraction. The

brake vibration is caused by excessive

flow of hydraulic fluid into the alternate

system metering valves during gear

retract braking.

Excessive brake vibration could result

in failure of the brake housing in the

torque rod region. This condition, if not

corrected, could reduce the braking

capability of the airplane and/or prevent

the extension of a main landing gear by

any method.

Explanation of Relevant Service

Information

The FAA has reviewed and approved

Boeing Service Bulletin 767–32–0152,

dated June 6, 1996; Revision 1, dated

June 27, 1996; and Revision 2, dated

July 10, 1997. These service bulletins

describe procedures for replacement of

the hydraulic reducer fitting in the

return port of the alternate brake

selector valve with a new restrictor

fitting. Accomplishment of the

replacement specified in the service

bulletins is intended to adequately

address the identified unsafe condition.

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 accomplishment of the actions

specified in the service bulletins

described previously.

Cost Impact

There are approximately 373

airplanes of the affected design in the

worldwide fleet. The FAA estimates that

86 airplanes of U.S. registry would be

affected by this proposed AD, and that

it would take approximately 4 work

hours per airplane to accomplish the

proposed replacement at an average

labor rate of $60 per work hour.

Required parts would cost

approximately $104 per airplane. Based

on these figures, the cost impact of the

replacement proposed by this AD on

U.S. operators is estimated to be

$29,584, or $344 per airplane.

The cost impact figure discussed

above 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.

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.

§ 39.13 [Amended]

2. Section 39.13 is amended by

adding the following new airworthiness

directive:

Boeing: Docket 97–NM–241–AD.

Applicability: Model 767–200, –300, and

–300F series airplanes, line positions 1

through 607 inclusive; equipped with carbon

brakes; 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 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 (b) 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 brake housing in

the torque rod region, which could reduce

the braking capability of the airplane and/or

prevent the extension of a main landing gear,

accomplish the following:

(a) Within 360 days after the effective date

of this AD, replace the hydraulic reducer

fitting in the return port of the alternate brake

selector valve with a new restrictor fitting, in

accordance with Boeing Service Bulletin

767–32–0152, dated June 6, 1996; Revision 1,

dated June 27, 1996; or Revision 2, dated July

10, 1997.

(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, 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 2: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Seattle ACO.

(c) 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.
Federal Register / Vol. 63, No. 149 /Tuesday, August 4, 1998 / Proposed Rules 41483

Issued in Renton, Washington, on July 27,

1998.

S.R. Miller,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 98–20677 Filed 8–3–98; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97–NM–87–AD]

RIN 2120–AA64

Airworthiness Directives; Boeing

Model 747–100, –200, and –300 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 747–100, –200,

and –300 series airplanes. This proposal

would require repetitive inspections to

detect cracking of certain lower lobe

fuselage frames, and repair, if necessary.

This proposal is prompted by reports

indicating that fatigue cracks were

found in lower lobe frames on the left

side of the fuselage. The actions

specified by the proposed AD are

intended to detect and correct fatigue

cracking of certain lower lobe fuselage

frames, which could lead to fatigue

cracks in the fuselage skin, and

consequent rapid decompression of the

airplane.

DATES: Comments must be received by

September 18, 1998.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 97–NM–

87–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: Bob

Breneman, Aerospace Engineer,

Airframe Branch, ANM–120S, FAA,

Transport Airplane Directorate, Seattle

Aircraft Certification Office, 1601 Lind

Avenue, SW., Renton, Washington

98055–4056; telephone (425) 227–2776;

fax (425) 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 97–NM–87–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.

97–NM–87–AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

The FAA has received reports

indicating that fatigue cracking was

found on a total of 19 lower lobe

fuselage frames on Boeing Model 747

series airplanes. Two of these airplanes

had completely severed frame inner

chords, webs, and fail-safe chords on

adjacent frames. A severed frame will

result in increased fuselage skin

stresses, which could lead to skin

cracking. In the area of the lower lobe

fuselage frames from Body Station (BS)

1820 to BS 2100, the fuselage skin does

not have tearstraps to arrest a skin crack.

Instead of tearstraps, this area has failsafe chords attached to the fuselage

frames which reduce the stress levels in

the fuselage skin such that a crack in the

skin would be stopped. With a

completely severed fuselage frame inner

chord, web, and fail-safe chord, there is

nothing to prevent a skin crack from

propagating beyond several fuselage

frame bays. This condition, if not

detected and corrected, could result in

rapid decompression of the airplane.

Explanation of Relevant Service

Information

The FAA has reviewed and approved

Boeing Alert Service Bulletin 747–

53A2408, dated April 25, 1996, which

describes procedures for repetitive

detailed visual inspections to detect

cracking of the lower lobe fuselage

frames from BS 1820 to BS 2100, and

repair, if necessary.

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 accomplishment of the actions

specified in the alert service bulletin

described previously, except as

discussed below.

Differences Between the Proposed AD

and Relevant Service Bulletin

Operators should note that, unlike the

initial compliance time (specified as

prior to the accumulation of 16,000 total

flight cycles, or within 1,500 flight

cycles or 18 months, whichever occurs

first) for airplanes identified in the alert

service bulletin, the proposed AD would

require that those airplanes be inspected

prior to the accumulation of 15,000 total

flight cycles, or within 1,500 flight

cycles or 18 months, whichever occurs

first. Because the FAA received a report

of cracking on an airplane that had

accumulated only 15,227 total flight

cycles, the FAA finds a compliance

threshold of 15,000 total flight cycles for

initiating the proposed actions to be

warranted, in that it represents an

appropriate interval of time allowable

for affected airplanes to continue to

operate without compromising safety.

Operators also should note that,

although the alert service bulletin

allows discount from the compliance

threshold of all flight cycles at or below

a cabin pressure differential of 2.0

pounds per square inch (psi), the

proposed AD does not. The FAA

received a report of cracking on an

airplane that had accumulated 12,817

full pressure cycles, plus 8,761 cycles at

less than 2.0 psi differential pressure.

The reported cracking was more