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

67311

Vol. 65, No. 218

Thursday, November 9, 2000

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98–NM–283–AD]

RIN 2120–AA64

Airworthiness Directives; Boeing

Model 747 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

Boeing Model 747–100 series airplanes,

that currently requires repetitive

inspections to detect cracking of the

outer chord of the body station (BS)

1480 upper and lower bulkhead and

longeron splice fitting; repair, if

necessary; and modification of the skin

splice plate, the outer chord splice

fitting, and the stringer interface of the

lower bulkhead, if necessary. This

action would revise the applicability of

the existing AD to add additional

airplanes, require accomplishment of

previously optional inspections and

clarify those inspections, extend certain

compliance times, and require

additional work in certain areas. This

proposal is prompted by reports that

fatigue cracking has been found in the

outer chord of the BS 1480 bulkhead at

the overwing longeron splice on

airplanes not subject to the existing AD.

The actions specified in this proposed

AD are intended to detect and correct

fatigue cracking of the outer chord of the

BS 1480 upper and lower bulkhead and

longeron splice fitting, which could

result in reduced structural integrity of

the fuselage and the inability to carry

limit load.

DATES: Comments must be received by

December 26, 2000.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 98–NM–

283–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. Comments may be

submitted via fax to (425) 227–1232.

Comments may also be sent via the

Internet using the following address: 9-

anm-nprmcomment@faa.gov. Comments

sent via fax or the Internet must contain

‘‘Docket No. 98–NM–283–AD’’ in the

subject line and need not be submitted

in triplicate. Comments sent via the

Internet as attached electronic files must

be formatted in Microsoft Word 97 for

Windows or ASCII text.

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: Rick

Kawaguchi, Aerospace Engineer,

Airframe Branch, ANM–120S, FAA,

Seattle Aircraft Certification Office,

1601 Lind Avenue, SW., Renton,

Washington 98055–4056; telephone

(425) 227–1153; 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 98–NM–283–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.

98–NM–283–AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

On September 15, 1998, the FAA

issued AD 98–20–25, amendment 39–

10791 (63 FR 50508, September 22,

1998), applicable to certain Boeing

Model 747–100 series airplanes, to

require repetitive inspections to detect

cracking of the outer chord of the body

station (BS) 1480 upper and lower

bulkhead and longeron splice fitting,

and repair, if necessary. Alternatively,

that action requires other repetitive

inspections to detect cracking of the BS

1480 upper and lower bulkhead,

bulkhead outer chord, web, skin, splice

components, and lower bulkhead/

stringer interface; and modification of

the skin splice plate, the outer chord

splice fitting, and the stringer interface

of the lower bulkhead, if necessary. That

action was prompted by a report

indicating that fatigue cracking was

found in the outer chord of the BS 1480

bulkhead at the overwing longeron

splice, and that the longeron splice

fitting was completely severed. The

requirements of that AD are intended to

detect and correct such fatigue cracking,

which could result in reduced structural

integrity of the fuselage and the inability

to carry limit load.

Actions Since Issuance of Previous Rule

Since the issuance of AD 98–20–25,

the FAA has determined that the

detailed visual inspections described in

paragraph (a)(1) of that AD as one

alternative for compliance with that AD

may not be adequate to ensure that any

fatigue cracking will be detected in a

timely manner. Therefore, this action

proposes to require detailed visual,

ultrasonic, and open-hole high

67312 Federal Register / Vol. 65, No. 218 / Thursday, November 9, 2000 / Proposed Rules

frequency eddy current (HFEC)

inspections which were referenced in

paragraph (a)(2) of AD 98–20–25 as

another alternative for compliance with

that AD.

Paragraph (a)(2) of AD 98–20–25

specifies repetitive inspections of both

the upper and lower bulkhead,

bulkhead outer chord, web, skin, splice

components, and lower bulkhead/

stringer interface. The initial inspection

is required prior to the accumulation of

10,000 total flight cycles, or within 45

days after October 7, 1998 (the effective

date of AD 98–20–25), whichever occurs

later. Since the issuance of AD 98–20–

25, the FAA has determined that it is

appropriate to extend the inspection

threshold for the inspection of the

bulkhead outer chord, skin, and lower

bulkhead/stringer interface. The FAA

finds that a repetitive inspection

threshold of 20,000 total flight cycles for

inspection of the lower bulkhead/

stringer interface is adequate to ensure

the continued safety of the affected

airplanes.

Explanation of New Relevant Service

Information

Since the issuance of AD 98–20–25,

the FAA has reviewed and approved

Boeing Alert Service Bulletin 747–

53A2390, Revision 1; including

Appendices A, B, C, and D; dated July

6, 2000. (AD 98–20–25 references the

original issue of that service bulletin,

dated July 31, 1997, as an appropriate

source of service information.) Like the

original issue of the service bulletin,

Revision 1 describes procedures for

repetitive inspections to detect cracking

of the BS 1480 upper and lower

bulkhead, bulkhead outer chord, web,

skin, splice components, and lower

bulkhead/stringer interface; repair, if

necessary; and, as part of a certain

inspection plan, procedures for

modification of the skin splice plate,

outer chord splice fitting, and the

stringer interface of the lower bulkhead.

Revision 1 of the service bulletin

expands the effectivity listing specified

in the original issue of the service

bulletin to include Model 747–400

series airplanes up to line number 1254,

includes new instructions for inspection

and modification at stringer S–34 in the

lower bulkhead/stringer interface area,

revises inspection procedures for

airplanes with a reinforcement strap

installed on the bulkhead outer chord,

and references new repair instructions.

Explanation of Applicability

In the preamble to AD 98–20–25, the

FAA specified that the actions required

by that AD were considered ‘‘interim

action’’ and that the FAA was

considering further rulemaking action to

supersede that AD to require

inspections and modification of the

upper and lower bulkhead and

overwing longeron at BS 1480 for all

Boeing Model 747–100, –200, and –300

series airplanes. The FAA has

determined that further rulemaking is

indeed necessary; this proposed AD

follows from that determination.

In addition, as specified previously,

Revision 1 of the service bulletin adds

Boeing Model 747–400 series airplanes

up to line number 1254 to the effectivity

listing. The area of the outer chord of

the BS 1480 upper bulkhead on Model

747–400 series airplanes up to and

including line number 1096 is

essentially the same as that on other

Boeing Model 747 series airplanes.

Therefore, this proposed AD would

require the same inspections of the

upper bulkhead for Boeing Model 747–

400 series airplanes up to and including

line number 1096 as it would require for

other Boeing Model 747 series airplanes.

Improvements were made during

production on the upper bulkhead area

on Model 747–400 series airplanes

having line numbers 1097 through 1254

inclusive; however, the lower bulkhead

area on those airplanes is also

essentially the same as on other Model

747 series airplanes. Therefore, this

proposed AD also would require the

same inspections of the lower bulkhead

for Boeing Model 747–400 series

airplanes up to and including line

number 1254 as it would require for

other Boeing Model 747 series airplanes.

Improvements were made during

production on the lower bulkhead area

on Model 747–400 series airplanes

having line number 1255 and above, so

those airplanes are not subject to this

proposed AD.

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

supersede AD 98–20–25 to continue to

require repetitive inspections to detect

cracking of the outer chord of the BS

1480 upper and lower bulkhead and

longeron splice fitting; repair, if

necessary; and modification of the skin

splice plate, the outer chord splice

fitting, and the stringer interface of the

lower bulkhead, if necessary. This

proposed AD would require

accomplishment of the actions specified

in Revision 1 of the service bulletin

described previously, except as

discussed below.

Differences Between Service Bulletin

and Proposed AD

Operators should note that, although

the service bulletin specifies that the

manufacturer may be contacted for

disposition of certain repair conditions,

this proposed AD would require the

repair of those conditions to be

accomplished in accordance with a

method approved by the FAA, or in

accordance with data meeting the type

certification basis of the airplane

approved by a Boeing Company

Designated Engineering Representative

who has been authorized by the FAA to

make such findings.

Explanation of Changes Made to AD

98–20–25

Paragraph (a)(2) of this AD is

essentially a restatement of paragraph

(a)(2) of AD 98–20–25; however, the

FAA has revised paragraph (a)(2) of this

proposed AD to more accurately state

the inspections included in that

paragraph. The inspections specified in

paragraph (a)(2) of this proposed AD are

the same as those specified in paragraph

(d) of this proposed AD. Thus, an

operator who has inspected an airplane

in accordance with paragraph (a)(2) of

this AD is not required to inspect in

accordance with paragraphs (c) and (d)

of this AD.

In addition, the FAA has added a note

to the proposed rule to clarify the

definition of a detailed visual

inspection.

Cost Impact

There are approximately 1,128

airplanes of the affected design in the

worldwide fleet. The FAA estimates that

259 airplanes of U.S. registry would be

affected by this proposed AD.

AD 98–20–25 applies to airplanes

listed in Groups 1 through 3 of the

service bulletin. The detailed visual

inspection that is currently offered as

one alternative for compliance with AD

98–20–25 takes approximately 16 work

hours per airplane to accomplish, at an

average labor rate of $60 per work hour.

Based on these figures, the cost impact

of the currently required actions on U.S.

operators is estimated to be $960 per

airplane, per inspection cycle.

For airplanes listed in Groups 1

through 3 in the service bulletin (34

U.S.-registered airplanes), the proposed

detailed visual, ultrasonic, and open

hole HFEC inspections of the upper

bulkhead area (which AD 98–20–25

references as an alternative inspection

program) would take approximately 32

work hours per airplane to accomplish,

at an average labor rate of $60 per work

hour. Based on these figures, the cost

Federal Register / Vol. 65, No. 218 / Thursday, November 9, 2000 / Proposed Rules 67313

impact of these proposed inspections on

U.S. operators is estimated to be

$65,280, or $1,920 per airplane, per

inspection cycle.

For airplanes listed in Groups 4

through 22 in the service bulletin (191

U.S.-registered airplanes), the proposed

detailed visual, ultrasonic, and open

hole HFEC inspections of the upper

bulkhead area would take

approximately 22 work hours per

airplane to accomplish, at an average

labor rate of $60 per work hour. Based

on these figures, the cost impact of these

inspections on U.S. operators is

estimated to be $252,120, or $1,320 per

airplane, per inspection cycle.

For all airplanes listed in the

applicability of this proposed AD (259

U.S.-registered airplanes), the proposed

detailed visual, ultrasonic, and open

hole HFEC inspections of the lower

bulkhead/stringer interface area would

take approximately 30 work hours per

airplane to accomplish, at an average

labor rate of $60 per work hour. Based

on these figures, the cost impact of these

proposed inspections on U.S. operators

is estimated to be $466,200, or $1,800

per airplane, per inspection cycle.

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. The

cost impact figures discussed in AD

rulemaking actions represent only the

time necessary to perform the specific

actions actually required by the AD.

These figures typically do not include

incidental costs, such as the time

required to gain access and close up,

planning time, or time necessitated by

other administrative actions.

Regulatory Impact

The regulations proposed herein

would not have a substantial direct

effect 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,

it is determined that this proposal

would not have federalism implications

under Executive Order 13132.

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

removing amendment 39–10791 (63 FR

50508, September 22, 1998), and by

adding a new airworthiness directive

(AD), to read as follows:

Boeing: Docket 98–NM–283–AD. Supersedes

AD 98–20–25, Amendment 39–10791.

Applicability: Model 747 series airplanes,

line numbers (L/N) 1 through 1254 inclusive,

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 (j)(1) 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 detect and correct fatigue cracking in

the outer chord of the body station (BS) 1480

bulkhead at the overwing longeron splice,

which could result in reduced structural

integrity of the fuselage and the inability to

carry limit load, accomplish the following:

Restatement of Requirements of AD 98–20–

25:

Repetitive Inspections and Repair

(a) For Model 747–100 series airplanes, L/

N 1 through 87 inclusive: Prior to the

accumulation of 10,000 total flight cycles, or

within 45 days after October 7, 1998 (the

effective date of AD 98–20–25, amendment

39–10791), whichever occurs later,

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

this AD.

(1) Perform a detailed visual inspection to

detect cracking of the longeron splice fitting

at BS 1480, the forward side of the outer

chord of the BS 1480 bulkhead at the

longeron splice fitting attachment bolts, and

the aft side of the outer chord of the BS 1480

bulkhead within two inches above the outer

chord splice fitting, on both the left and right

sides of the airplane.

Note 2: Figure 5 of Boeing Alert Service

Bulletin 747–53A2390, dated July 31, 1997,

provides an exploded view of the structural

components of the splice area for the purpose

of parts identification. (However, paragraph

(a)(1) of this AD does not require the

inspection described in Figure 5.)

Note 3: 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.’’

(i) If any cracking is detected, prior to

further flight, repair in accordance with a

method approved by the Manager, Seattle

Aircraft Certification Office (ACO), FAA; or

in accordance with data meeting the type

certification basis of the airplane approved

by a Boeing Company Designated

Engineering Representative (DER) who has

been authorized by the Manager, Seattle

ACO, to make such findings. For a repair

method to be approved by the Manager,

Seattle ACO, as required by this paragraph,

the approval letter must specifically

reference this AD.

(ii) Repeat the detailed visual inspection

thereafter at intervals not to exceed 250 flight

cycles, until the initial inspection required

by paragraph (a)(2) or (d) of this AD is

accomplished.

(2) Perform detailed visual, ultrasonic, and

open hole high frequency eddy current

(HFEC) inspections to detect cracking of the

upper and lower bulkhead, bulkhead outer

chord, web, skin, splice components, and

lower bulkhead/stringer interface, in

accordance with Figures 5 and 8 of Boeing

Alert Service Bulletin 747–53A2390, dated

July 31, 1997. Additionally, for airplanes on

which the inspection in ‘‘Plan B’’ of the

service bulletin is accomplished, modify the

skin splice plate, the outer chord splice

fitting, and the stringer interface of the lower

bulkhead, in accordance with the

Accomplishment Instructions of the service

bulletin. Accomplishment of these actions

constitutes terminating action for the

repetitive inspection requirements of

paragraph (a)(1) of this AD.

(i) If any cracking is detected, prior to

further flight, repair in accordance with the

service bulletin, except as provided by

paragraph (b) of this AD.

(ii) Repeat the inspections thereafter in

accordance with the flight safety inspection

67314 Federal Register / Vol. 65, No. 218 / Thursday, November 9, 2000 / Proposed Rules

program specified in Figures 1 and 3 of the

service bulletin.

(b) Where the service bulletin specifies that

the manufacturer may be contacted for

disposition of certain repair conditions,

repair in accordance with a method approved

by the Manager, Seattle ACO; or in

accordance with data meeting the type

certification basis of the airplane approved

by a Boeing Company DER who has been

authorized by the Manager, Seattle ACO, to

make such findings. For a repair method to

be approved by the Manager, Seattle ACO, as

required by this paragraph, the approval

letter must specifically reference this AD.

New Requirements of This AD

Groups 1 Through 3: Splice Area Work

(Compliance Times)

Note 4: Airplanes inspected in accordance

with paragraph (a)(2) of this AD are not

required to be inspected in accordance with

paragraphs (c) and (d) of this AD.

(c) For airplanes listed in Groups 1 through

3 in Boeing Alert Service Bulletin 747–

53A2390, Revision 1; including Appendices

A, B, C, and D; dated July 6, 2000; on which

the requirements of paragraph (a)(2) of this

AD have NOT been accomplished prior to the

effective date of this AD: Accomplish

paragraph (d) of this AD at the applicable

time specified in paragraph (c)(1), (c)(2), or

(c)(3) of this AD.

(1) For airplanes on which the inspection

specified in Boeing Service Bulletin 747–53–

2333 has not been accomplished: Inspect

prior to the accumulation of 10,000 total

flight cycles, or within 1,000 flight cycles

after the effective date of this AD, whichever

occurs later.

(2) For airplanes on which the inspection

specified in Boeing Service Bulletin 747–53–

2333 has been accomplished, but the full

modification specified in that service bulletin

has not been accomplished: Inspect at the

later of the times specified in paragraphs

(c)(2)(i) and (c)(2)(ii) of this AD.

(i) Prior to the accumulation of 10,000 total

flight cycles, or within 2,000 flight cycles

after accomplishment of the last inspection

in accordance with Boeing Service Bulletin

747–53–2333, whichever occurs first.

(ii) Within 1,000 flight cycles after the

effective date of this AD.

(3) For airplanes on which the full

modification specified in Boeing Service

Bulletin 747–53–2333 has been

accomplished: Inspect at the later of the

times specified in paragraphs (c)(3)(i) and

(c)(3)(ii) of this AD.

(i) Prior to the accumulation of 16,000 total

flight cycles, or within 6,000 flight cycles

after accomplishment of the full modification

in accordance with Boeing Service Bulletin

747–53–2333, whichever occurs first.

(ii) Within 1,000 flight cycles after the

effective date of this AD.

Groups 1 Through 3: Splice Area Work

(Inspections)

(d) For airplanes listed in Groups 1 through

3 in Boeing Alert Service Bulletin 747–

53A2390, Revision 1; including Appendices

A, B, C, and D; dated July 6, 2000; on which

the requirements of paragraph (a)(2) of this

AD have NOT been accomplished prior to the

effective date of this AD: At the applicable

time specified in paragraph (c) of this AD,

accomplish paragraph (d)(1) or (d)(2) of this

AD. Accomplishment of the requirements of

this paragraph constitutes terminating action

for the repetitive inspection requirements

specified in paragraph (a)(1) of this AD, or,

for the upper bulkhead splice area ONLY, for

the inspection requirements specified in

paragraph (a)(2) of this AD.

(1) Plan ‘‘A’’: Perform detailed visual,

ultrasonic, and HFEC inspections to detect

cracking of the splice area, in accordance

with Plan ‘‘A’’ and Figure 5, as defined in the

Accomplishment Instructions of Boeing Alert

Service Bulletin 747–53A2390, Revision 1;

including Appendices A, B, C, and D; dated

July 6, 2000. Repeat the inspections

thereafter in accordance with the flight safety

inspection program as specified under Plan

‘‘A’’ and Figure 1 of the service bulletin.

(2) Plan ‘‘B’’: Modify the skin splice plate

and outer chord splice fitting in accordance

with Plan ‘‘B,’’ as defined in the

Accomplishment Instructions of Boeing Alert

Service Bulletin 747–53A2390, Revision 1;

including Appendices A, B, C, and D; dated

July 6, 2000. Perform HFEC inspections and

modification, then accomplish repeat open

hole HFEC inspections, in accordance with

the flight safety inspection program, as

specified under Plan ‘‘B’’ and Figure 1 of the

service bulletin. Accomplishment of the

modification and inspections in accordance

with this paragraph terminates the repetitive

inspection requirements in paragraph (d)(1)

of this AD.

Groups 4 Through 22: Splice Area Work

(Compliance Time and Inspections)

(e) For airplanes listed in Groups 4 though

22 in Boeing Alert Service Bulletin 747–

53A2390, Revision 1; including Appendices

A, B, C, and D; dated July 6, 2000: Prior to

the accumulation of 16,000 total flight cycles,

or within 1,000 flight cycles after the

effective date of this AD, whichever occurs

later, perform detailed visual and ultrasonic

inspections to detect cracking of the

bulkhead forward flange in accordance with

Figure 7 of the service bulletin, and

accomplish the requirements of either

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

(1) Plan ‘‘A’’: Perform open hole HFEC

inspections to detect cracking of the splice

area, in accordance with Plan ‘‘A’’ and

Figures 6 and 7, as defined in the

Accomplishment Instructions of the service

bulletin. Repeat the inspections thereafter in

accordance with the flight safety inspection

program as specified under Plan ‘‘A’’ and in

Figure 2 of the service bulletin.

(2) Plan ‘‘B’’: Perform open hole HFEC

inspections and modification of the upper

bulkhead, bulkhead outer chord, web, skin,

and splice components; in accordance with

Plan ‘‘B,’’ as defined in the Accomplishment

Instructions of Boeing Alert Service Bulletin

747–53A2390, Revision 1; including

Appendices A, B, C, and D; dated July 6,

2000. Thereafter, repeat the open hole HFEC

inspections in accordance with the flight

safety inspection program as specified under

Plan ‘‘B’’ and Figure 2 of the service bulletin.

Accomplishment of the modification and

inspections in accordance with this

paragraph terminates the repetitive

inspection requirements specified in

paragraph (e)(1) of this AD.

All Airplanes: Lower Bulkhead/Stringer

Interface Work (Compliance Times)

(f) For all airplanes (L/N 1 through 1254

inclusive): At the applicable time specified in

paragraph (f)(1) or (f)(2) of this AD,

accomplish paragraph (g) of this AD.

(1) For airplanes on which an inspection of

the lower bulkhead has NOT been

accomplished prior to the effective date of

this AD in accordance with paragraph (a)(2)

of this AD: Inspect prior to the accumulation

of 20,000 total flight cycles, or within 1,000

flight cycles after the effective date of this

AD, whichever occurs later.

(2) For airplanes on which an inspection of

the lower bulkhead HAS been accomplished

prior to the effective date of this AD in

accordance with paragraph (a)(2) of this AD:

Inspect prior to the accumulation of 20,000

total flight cycles, or at the time of the next

scheduled inspection of the lower bulkhead

in accordance with paragraph (a)(2) of this

AD, whichever occurs later.

All Airplanes: Lower Bulkhead/Stringer

Interface Work (Inspections)

(g) For all airplanes (L/N 1 through 1254

inclusive): At the applicable time specified in

paragraph (f) of this AD, accomplish

paragraph (g)(1) or (g)(2) of this AD. For

airplanes having L/N 1 through 87 inclusive,

accomplishment of the requirements of this

paragraph constitutes terminating action for

the inspection requirements specified in

paragraph (a)(2) of this AD for the lower

bulkhead/stringer interface area ONLY.

(1) Plan ‘‘A’’: Perform detailed visual and

either ultrasonic or open hole HFEC

inspections, as applicable, to detect cracking

of the lower bulkhead/stringer interface area,

in accordance with Plan ‘‘A’’ and Figure 8,

as defined in the Accomplishment

Instructions of Boeing Alert Service Bulletin

747–53A2390, Revision 1; including

Appendices A, B, C, and D; dated July 6,

2000. Repeat the inspections thereafter in

accordance with the flight safety program as

specified under Plan ‘‘A’’ and Figure 3 or

Figure 8 of the service bulletin.

(2) Plan ‘‘B’’: Except as provided by

paragraph (h) of this AD, perform open hole

HFEC inspections and modification of the

lower bulkhead/stringer interface area, in

accordance with Plan ‘‘B’’ and Figure 19, as

defined in the Accomplishment Instructions

of Boeing Alert Service Bulletin 747–

53A2390, Revision 1; including Appendices

A, B, C, and D; dated July 6, 2000. Thereafter,

repeat the detailed visual and either

ultrasonic or open hole HFEC inspections, as

applicable, in accordance with the flight

safety inspection program as specified under

Plan ‘‘B’’ and Figures 3 and 8 of the service

bulletin. Accomplishment of the

modification and inspections in accordance

with this paragraph terminates the repetitive

inspection requirements specified in

paragraph (g)(1) of this AD.

Federal Register / Vol. 65, No. 218 / Thursday, November 9, 2000 / Proposed Rules 67315

Airplanes Modified With Original Service

Bulletin: Post-Modification Work

(h) For any airplane (L/N 1 through 1254

inclusive) on which the modification

specified in paragraph (g)(2) was

accomplished prior to the effective date of

this AD in accordance with the original issue

of Boeing Alert Service Bulletin 747–

53A2390, dated July 31, 1997: Prior to the

accumulation of 20,000 total flight cycles, or

within 2,000 flight cycles after the effective

date of this AD, whichever occurs later,

accomplish post-modification work in

accordance with Figure 26 of Boeing Alert

Service Bulletin 747–53A2390, Revision 1;

including Appendices A, B, C, and D; dated

July 6, 2000.

Repair

(i) Except as provided by paragraph (b) of

this AD, if any cracking is detected during

any inspection required by this AD, prior to

further flight, repair in accordance with

Boeing Alert Service Bulletin 747–53A2390,

Revision 1; including Appendices A, B, C,

and D; dated July 6, 2000.

Alternative Methods of Compliance

(j)(1) 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

ACO. 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.

(2) Alternative methods of compliance,

approved previously in accordance with AD

98–20–25, amendment 39–10791, are

approved as alternative methods of

compliance with paragraph (a) of this AD.

Note 5: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Seattle ACO.

Special Flight Permits

(k) Special flight permits may be issued in

accordance with §§ 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

November 2, 2000,

Donald L. Riggin,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 00–28723 Filed 11–8–00; 8:45 am]

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99–CE–75–AD]

RIN 2120–AA64

Airworthiness Directives; Rolladen

Schneider Flugzeugbau GmbH Models

LS 4 and LS 4a Sailplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes to

adopt a new airworthiness directive

(AD) that would apply to certain

Rolladen Schneider Flugzeugbau GmbH

(Rolladen Schneider) Models LS 4 and

LS 4a sailplanes. The proposed AD

would require you to inspect the

airbrake system for damage and proper

rigging, with correction, repair, or

replacement, as necessary. The

proposed AD would also require you to

report any damage found to the Federal

Aviation Administration (FAA). The

proposed AD is the result of mandatory

continuing airworthiness information

(MCAI) issued by the airworthiness

authority for Germany. The actions

specified by the proposed AD are

intended to detect and correct damage

to the airbrake locking bracket caused

by asymmetric loads. This condition

could result in the pilot’s inability to

operate the airbrake controls, with

consequent loss of sailplane control.

DATES: The Federal Aviation

Administration (FAA) must receive any

comments on this proposed rule on or

before December 14, 2000.

ADDRESSES: Submit comments in

triplicate to FAA, Central Region, Office

of the Regional Counsel, Attention:

Rules Docket No. 99–CE–75–AD, 901

Locust, Room 506, Kansas City,

Missouri 64106. Comments may be

inspected at this location between 8

a.m. and 4 p.m., Monday through

Friday, holidays excepted.

Service information that applies to the

proposed AD may be obtained from

Rolladen-Schneider Flugzeugbau

GmbH, Muhlstrasse 10, D–63329

Egelsbach, Germany; phone: ++ 49 6103

204126; facsimile: ++ 49 6103 45526.

This information also may be examined

at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT: Mr.

Mike Kiesov, Aerospace Engineer, FAA,

Small Airplane Directorate, 901 Locust,

Room 301, Kansas City, Missouri 64106;

telephone: (816) 329–4144; facsimile:

(816) 329–4090.

SUPPLEMENTARY INFORMATION:

Comments Invited

How do I comment on the proposed

AD? The FAA invites comments on this

proposed rule. You may submit

whatever written data, views, or

arguments you choose. You need to

include the rule’s docket number and

submit your comments in triplicate to

the address specified under the caption

ADDRESSES.The FAA will consider all

comments received on or before the

closing date. We may amend the

proposed rule in light of comments

received. Factual information that

supports your ideas and suggestions is

extremely helpful in evaluating the

effectiveness of the proposed AD action

and determining whether we need to

take additional rulemaking action.

Are there any specific portions of the

proposed AD I should pay attention to?

The FAA specifically invites comments

on the overall regulatory, economic,

environmental, and energy aspects of

the proposed rule that might suggest a

need to modify the rule. You may

examine all comments we receive before

and after the closing date of the rule in

the Rules Docket. We will file a report

in the Rules Docket that summarizes

each FAA contact with the public that

concerns the substantive parts of the

proposed AD.

We are re-examining the writing style

we currently use in regulatory

documents, in response to the

Presidential memorandum of June 1,

1998. That memorandum requires

federal agencies to communicate more

clearly with the public. We are

interested in your comments on whether

the style of this document is clearer, and

any other suggestions you might have to

improve the clarity of FAA

communications that affect you. You

can get more information about the

Presidential memorandum and the plain

language initiative at http://

www.plainlanguage.gov.

How can I be sure FAA receives my

comment? If you want us to

acknowledge the receipt of your

comments, you must include a selfaddressed, stamped postcard. On the

postcard, write ‘‘Comments to Docket

No. 99–CE–75–AD.’’ We will date stamp

and mail the postcard back to you.

Discussion

What events have caused this

proposed AD? The LBA, which is the

airworthiness authority for Germany,

recently notified FAA that an unsafe

condition may exist on certain Rolladen

Schneider Models LS 4 and LS 4a

sailplanes. The LBA reports two

occurrences of damaged airbrake