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

37494

Vol. 65, No. 116

Thursday, June 15, 2000

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99–NM–350–AD]

RIN 2120–AA64

Airworthiness Directives; Boeing

Model 747–400, 747–400F, 757–200,

757–200CB, 757–200PF, 767–200, 767–

300, and 767–300F 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 747–400, 757–200, 767–

200, and 767–300 series airplanes. That

AD currently requires repetitive checks

to detect certain failures in the warning

electronic unit (WEU) or modular

avionic warning electronic assembly

(MAWEA); repetitive tests to detect any

failure of tactile, visual, or aural alerts

generated by the WEU or MAWEA; and

corrective action, if necessary. This

action would make these requirements

applicable to other airplanes on which

the defective power supplies may be

installed, eliminate the repetitive tests

for certain airplanes, and increase the

interval for the repetitive tests for

certain other airplanes. This action also

would require replacement of the

existing power supplies in the WEU or

MAWEA with modified, new, or

serviceable power supplies. The actions

specified by the proposed AD are

intended to prevent failure of the WEU

or MAWEA power supplies, which

could result in loss of visual, aural, and

tactile alerts to the flightcrew. Absence

of such alerts could result in the

flightcrew being unaware that an

immediate or appropriate action should

be taken in the event of an unsafe

condition.

DATES: Comments must be received by

July 31, 2000.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 99–NM–

350–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:

Sheila I. Mariano, 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) 227–2675; 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 99–NM–350–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.

99–NM–350–AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

On August 24, 1999, the FAA issued

AD 99–18–16, amendment 39–11282 (64

FR 47653, September 1, 1999),

applicable to certain Boeing Model 747–

400, 757–200, 767–200, and 767–300

series airplanes. That AD requires

repetitive checks to detect certain

failures in the warning electronic unit

(WEU) or modular avionic warning

electronic assembly (MAWEA);

repetitive tests to detect any failure of

tactile, visual, or aural alert generated

by the WEU or MAWEA; and corrective

action, if necessary. The AD also

provides for optional terminating action

for the repetitive checks and tests. That

action was prompted by a report of a

MAWEA power supply failure due to

inadequate over-voltage protection. The

requirements of that AD are intended to

detect and correct such a failure, which

could result in loss of visual, aural, and

tactile alerts to the flightcrew. Absence

of such alerts could result in the

flightcrew being unaware that an

immediate or appropriate action should

be taken in the event of an unsafe

condition.

Actions Since Issuance of Previous Rule

In the preamble to AD 99–18–16, the

FAA indicated that the actions required

by that AD were considered ‘‘interim

action’’ and that further rulemaking

action was being considered to require

the accomplishment of the optional

terminating action specified in that AD.

The FAA now has determined that

further rulemaking action is indeed

necessary, and this proposed AD

follows from that determination. The

optional terminating action described in

AD 99–18–16 provides for replacement

of the existing power supplies of the

WEU or MAWEA with new power

supplies having part number 285T0035–

202 Mod A. However, since the issuance

of that AD, the FAA has determined that

several older power supplies are also

acceptable replacements for the existing

Federal Register / Vol. 65, No. 116 / Thursday, June 15, 2000 / Proposed Rules 37495

power supplies. Therefore, the proposed

AD would provide for installation of

certain other new or serviceable power

supplies, in addition to the new power

supply referenced for optional

terminating action in AD 99–18–16.

Additionally, the FAA has

determined that the defective power

supplies that were the subject of AD 99–

18–16 may have been installed as spares

on airplanes that did not originally have

the defective power supplies installed.

Accordingly, the FAA finds it is

necessary to expand the applicability of

the existing AD to include any Boeing

Model 747–400, 747–400F, 757–200,

757–200CB, 757–200PF, 767–200, 767–

300, or 767–300F series airplane

equipped with a WEU or MAWEA

power supply having the affected part

number, in order to prevent the

identified unsafe condition on these

airplanes.

Also, since the issuance of AD 99–18–

16, the FAA has determined that it is

not necessary for the system functional

tests required by paragraph (a) of that

AD to be accomplished on Boeing

Model 747–400 and –400F series

airplanes. The FAA finds that the

internal MAWEA system ‘‘byte check’’

on Model 747–400 and –400F series

airplanes is sufficient to detect failures

of the MAWEA either in the air or on

the ground. Therefore, the requirement

for system functional tests on Boeing

Model 747–400 and –400F series

airplanes has not been included in this

AD. This AD continues to require

checks of the engine indication and

crew alerting system (EICAS) status

page before each flight to detect

MAWEA or WEU failure, as applicable,

for all airplanes subject to this AD.

Explanation of Relevant Service

Information

The FAA has reviewed and approved

Boeing Service Bulletin 747–31–2288,

Revision 2, dated November 18, 1999,

which describes procedures for

replacement of the power supplies in

the MAWEA of certain Boeing Model

747–400 and 747–400F series airplanes

with modified, new, or serviceable

power supplies.

The FAA also has reviewed and

approved Boeing Special Attention

Service Bulletins 757–31–0066,

Revision 2, and 767–31–0106, Revision

2, both dated November 18, 1999. These

service bulletins describe procedures for

replacing the power supplies in the

WEU card file of Boeing Model 757–

200, 757–200CB, 757–200PF, 767–200,

767–300, and 767–300F series airplanes

with modified, new, or serviceable

power supplies.

Accomplishment of the actions

specified in the service bulletins is

intended to adequately address the

identified unsafe condition.

The service bulletins described

previously refer to Boeing Component

Service Bulletin 285T0035–31–07, dated

December 17, 1998, as the appropriate

source of service information for

modification of WEU or MAWEA power

supplies having P/N 28T0035-201. The

modification of the power supplies

involves replacing a printed circuit card

and mounting screw, and changing the

part number to 285T0035–202 Mod A.

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 99–18–16 to continue to

require repetitive checks to detect

certain failures in the WEU or MAWEA

and, for certain airplanes, repetitive

tests to detect any failure of tactile,

visual, or aural alerts generated by the

WEU. This proposed AD would also

continue to require corrective action, if

necessary. This proposed AD would

expand the applicability of the existing

AD to include other airplanes on which

the defective power supplies may be

installed, increase the interval for the

repetitive tests, and add a requirement

for replacement of the existing power

supplies in the WEU or MAWEA with

modified, new, or serviceable power

supplies. The actions would be required

to be accomplished in accordance with

the applicable service bulletin described

previously.

Cost Impact

There are approximately 1,592

airplanes of the affected design in the

worldwide fleet. The FAA estimates that

802 airplanes of U.S. registry would be

affected by this proposed AD.

The repetitive checks and tests

required by AD 99–18–16 are currently

applicable to approximately 33 U.S.-

registered airplanes. The repetitive

checks and tests 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 of the currently required checks

and tests on U.S. operators is estimated

to be $1,980, or $60 per airplane, per

check/test cycle. Because this proposed

AD would eliminate the currently

required repetitive tests for certain

airplanes, and increase the repetitive

interval for the tests for certain other

airplanes, the proposed AD would result

in a reduction in costs to operators

currently subject to AD 99–18–16.

The repetitive checks and tests in this

new proposed action would be

applicable to approximately 769

additional airplanes. Based on the

figures discussed above, the new costs

to U.S. operators for the repetitive

checks and tests that would be imposed

by this proposed AD are estimated to be

$46,140, or $60 per airplane, per check/

test cycle.

For all airplanes subject to this

proposed AD, the new replacement that

is proposed in this AD action would

take approximately 3 work hours per

airplane to accomplish, at an average

labor rate of $60 per work hour.

Required parts would cost

approximately $6,424 per airplane.

Based on these figures, the cost impact

of the replacement proposed by this AD

action on U.S. operators is estimated to

be $5,296,408, or $6,604 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 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

37496 Federal Register / Vol. 65, No. 116 / Thursday, June 15, 2000 / Proposed Rules

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 39–11282 (64 FR

47653, September 1, 1999), and by

adding a new airworthiness directive

(AD), to read as follows:

Boeing: Docket 99–NM–350–AD. Supersedes

AD 99–18–16, Amendment 39–11282.

Applicability: Model 747–400, 747–400F,

757–200, 757–200CB, 757–200PF, 767–200,

767–300, and 767–300F series airplanes;

equipped with either a warning electronics

unit (WEU) or a modular avionics warning

electronic assembly (MAWEA) power supply

having part number (P/N) 285T0035–201;

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 (h)(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 prevent failure of the WEU or MAWEA

power supplies, which could result in loss of

visual, aural, and tactile alerts to the

flightcrew (the absence of which could result

in the flightcrew being unaware that an

immediate or appropriate action should be

taken in the event of an unsafe condition),

accomplish the following:

Partial Restatement of Requirements of AD

99–18–16

Model 747–400 Series Airplanes: EICAS

Status Page Checks

(a) For Model 747–400 and 747–400F

series airplanes having L/N 1121 through

1177 inclusive: Within 15 days after

September 16, 1999 (the effective date of AD

99–18–16, amendment 39–11282), check the

status page of the engine indication and crew

alerting system (EICAS) for any MAWEA

failure. Thereafter, repeat the EICAS status

page check before each flight until the

requirements of paragraph (c) or (f) of this AD

have been accomplished.

Model 757–200, 767–200, and 767–300 Series

Airplanes: Checks and Functional Tests

(b) For Model 757–200, –200CB, and

–200PF series airplanes having L/N 761

through 828 inclusive; and Model 767–200,

–300, and –300F series airplanes having L/N

668 through 723 inclusive: Within 15 days

after September 16, 1999, check the status

page of the EICAS for any WEU failure; and

perform the Work Instructions in Section 3,

Part 1, of Boeing Service Bulletin 757–31–

0066, Revision 1, dated December 17, 1998,

or Revision 2, dated November 18, 1999 (for

Model 757–200, –200CB, and –200PF series

airplanes); or Boeing Service Bulletin 767–

31–0106, Revision 1, dated December 17,

1998, or Revision 2, dated November 18,

1999 (for Model 767–200, 767–300, and 767–

300F series airplanes); as applicable; to

detect loss of any visual, aural, or tactile

alert. Thereafter, repeat the EICAS status

page check before each flight, and the Work

Instructions in Section 3, Part 1, of the

applicable service bulletin at intervals not to

exceed every ‘‘A’’ check or 45 days,

whichever occurs first, until the

requirements of paragraph (c) or (f) of this AD

has been accomplished. After the effective

date of this AD, only Revision 2 of the

applicable service bulletin shall be used.

Corrective Action

(c) If any failure of the MAWEA or WEU,

as applicable, or the loss of any visual, aural,

or tactile alert is detected during any test

required by either paragraph (a) or (b) of this

AD, prior to further flight, accomplish

paragraph (c)(1), (c)(2), or (c)(3) of this AD;

as applicable.

(1) For Model 747–400 or –400F series

airplanes: Replace the power supplies of the

MAWEA with new or modified power

supplies having P/N 285T0035–202 Mod A,

in accordance with either Boeing Service

Bulletin 747–31–2288, dated December 17,

1998, or Revision 1, dated January 28, 1999;

or with new, modified, or serviceable power

supplies having P/N 285T0035–202 Mod A,

P/N 285T0035–10, or P/N 285T0035–11; in

accordance with Boeing Service Bulletin

747–31–2288, Revision 2, dated November

18, 1999. Such replacement constitutes

terminating action for the requirements of

this AD. After the effective date of this AD,

only Revision 2 of the applicable service

bulletin shall be used.

(2) For Model 757–200, –200CB, and

–200PF series airplanes: Replace the power

supplies of the WEU with new or modified

power supplies having P/N 285T0035–202

Mod A, in accordance with Boeing Service

Bulletin 757–31–0066, Revision 1, dated

December 17, 1998; or with new, modified,

or serviceable power supplies having P/N

285T0035–202 Mod A, P/N 285T0035–9, P/

N 285T0035–10, or P/N 285T0035–11, in

accordance with Boeing Special Attention

Service Bulletin 757–31–0066, Revision 2,

dated November 18, 1999. Such replacement

constitutes terminating action for the

requirements of this AD. After the effective

date of this AD, only Revision 2 of the service

bulletin shall be used.

(3) For Model 767–200, –300, and –300F

series airplanes: Replace the power supplies

of the WEU with new or modified power

supplies having P/N 285T0035–202 Mod A,

in accordance with Boeing Service Bulletin

767–31–0106, Revision 1, dated December

17, 1998; or with new, modified, or

serviceable power supplies having P/N

285T0035–202 Mod A, P/N 285T0035–9, P/

N 285T0035–10, or P/N 285T0035–11; in

accordance with Boeing Special Attention

Service Bulletin 767–31–0106, Revision 2,

dated November 18, 1999. Such replacement

constitutes terminating action for the

requirements of this AD. After the effective

date of this AD, only Revision 2 of the

applicable service bulletin shall be used.

Note 2: Page 59 of Boeing Service Bulletin

747–31–2288, Revision 1, dated January 28,

1999, incorrectly references the Boeing 767

AMM as the appropriate source of service

information for accomplishment of the

removal and installation of the power supply.

However, the correct reference is the Boeing

747 AMM.

New Requirements of This AD

Note 3: Boeing Component Service Bulletin

285T0035–31–07, dated December 17, 1998,

describes procedures for modifying WEU or

MAWEA power supplies having P/N

28T0035–201 to 285T0035–202 Mod A.

Repetitive Checks: Model 747–400 and –400F

(d) For Model 747–400 and -400F series

airplanes other than those identified in

paragraph (a) of this AD: At the next ‘‘A’’

check or within 45 days, whichever occurs

first, check the status page of the EICAS for

any MAWEA failure.

(1) If no MAWEA failure is detected:

Thereafter, repeat the EICAS status page

check before each flight, until the

requirements of paragraph (e) are

accomplished.

(2) If any MAWEA failure is detected: Prior

to further flight, replace MAWEA power

supplies having P/N 285T0035–201 with new

or modified power supplies having P/N

285T0035–202 Mod A, or new or serviceable

power supplies having P/N 285T0035–10 or

P/N 285T0035–11; in accordance with

Boeing Service Bulletin 747–31–2288,

Revision 2, dated November 18, 1999. Such

replacement constitutes terminating action

for the requirements of this AD.

Repetitive Checks and Functional Tests:

Model 757 and 767

(e) For Model 757–200, 757–200CB, 757–

200PF, 767–200, 767–300, and 767–300F

series airplanes other than those identified in

paragraph (b) of this AD: At the next ‘‘A’’

check or within 45 days, whichever occurs

first, check the status page of the EICAS for

any WEU failure; and perform the Work

Instructions in Section 3, Part 1, of Boeing

Special Attention Service Bulletin 757–31–

0066, Revision 2, dated November 18, 1999;

or Boeing Special Attention Service Bulletin

767–31–0106, Revision 2, dated November

18, 1999; as applicable; to detect loss of any

visual, aural, or tactile alert.

(1) If no failure of the WEU or loss of any

visual, aural, or tactile alert is detected:

Thereafter, repeat the EICAS status page

check before each flight, and accomplish the

Work Instructions in Section 3, Part 1 of the

applicable service bulletin at intervals not to

exceed every ‘‘A’’ check or 45 days,

whichever occurs first, until the

requirements of paragraph (e) are

accomplished.

Federal Register / Vol. 65, No. 116 / Thursday, June 15, 2000 / Proposed Rules 37497

(2) If any failure of the WEU or loss of any

visual, aural, or tactile alert is detected: Prior

to further flight, replace WEU power supplies

having P/N 285T0035–201, with new or

modified power supplies having P/N

285T0035–202 Mod A; or new or serviceable

power supplies having P/N 285T0035–9, P/

N 285T0035–10, or P/N 285T0035–11; in

accordance with the applicable service

bulletin. Such replacement constitutes

terminating action for the requirements of

this AD.

Replacement

(f) Within 1 year after the effective date of

this AD, replace WEU or MAWEA power

supplies having P/N 285T0035–201, with

new or modified power supplies having P/N

285T0035–202 Mod A; or new or serviceable

power supplies having P/N 285T0035–9, P/

N 285T0035–10, or P/N 285T0035–11; in

accordance with Boeing Service Bulletin

747–31–2288, dated December 17, 1998,

Revision 1, dated January 28, 1999, or

Revision 2, dated November 18, 1999 (for

Model 747–400 and 747–400F series

airplanes); Boeing Service Bulletin 757–31–

0066, Revision 1, dated December 17, 1998,

or Revision 2, dated November 18, 1999 (for

Model 757–200, 757–200CB, and 757–200PF

series airplanes); or Boeing Service Bulletin

767–31–0106, Revision 1, dated December

17, 1998, or Revision 2, dated November 18,

1999 (for Model 767–200, 767–300, and 767–

300F series airplanes); as applicable. After

the effective date of this AD, only Revision

2 of the applicable service bulletin shall be

used. Such replacement constitutes

terminating action for the repetitive

inspection requirements of this AD.

Spares

(g) As of the date specified in paragraph

(g)(1) or (g)(2), as applicable, no person shall

install a WEU or MAWEA power supply

having Boeing P/N 285T0035–201 on any

airplane.

(1) For Model 747–400 series airplanes,

line numbers 1121 through 1177 inclusive;

Model 757–200, –200CB, and –200PF series

airplanes, line numbers 761 through 828

inclusive; and Model 767–200, 767–300, and

–300F series airplanes, line numbers 668

through 723 inclusive: As of September 16,

1999 (the effective date of AD 99–18–16,

amendment 39–11282).

(2) For airplanes other than those

identified in paragraph (g)(1) of this AD: As

of the effective date of this AD.

Alternative Methods of Compliance

(h)(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

Aircraft Certification Office (ACO), FAA,

Transport Airplane Directorate. Operators

shall submit their requests through an

appropriate FAA Principal Avionics

Inspector, who may add comments and then

send it to the Manager, Seattle ACO.

(2) Alternative methods of compliance,

approved previously by the FAA in

accordance with AD 99–18–16, amendment

39–11282, are approved as alternative

methods of compliance with this AD.

Note 4: 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

(i) 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 June 9,

2000.

Donald L. Riggin,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 00–15189 Filed 6–14–00; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99–NM–377–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

adoption of a new airworthiness

directive (AD) that is applicable to

certain Boeing Model 747 series

airplanes. This proposal would require

inspections to detect cracking of the

frame web, doubler, and inner chord of

the forward edge frame of main entry

door number 1, and various follow-on

actions. This proposal is prompted by

reports of cracking in the frame web,

doubler, inner chord, and strap of the

forward edge frame of main entry door

number 1. The actions specified by the

proposed AD are intended to prevent

cracks in the frame web and doubler of

the forward edge frame of main entry

door number 1, which could result in

inability of the edge frame to react door

stop loads, and consequent rapid

depressurization of the airplane.

DATES: Comments must be received by

July 31, 2000.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 99–NM–

377–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: Rick

Kawaguchi, Aerospace Engineer,

Airframe Branch, ANM–120S, FAA,

Transport Airplane Directorate, Seattle

Aircraft Certification Office, 1601 Lind

Avenue, SW., Renton, Washington

98055–4056; telephone (425) 227–1153;

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 99–NM–377–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.

99–NM–377–AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

The FAA has received reports

indicating that cracking has been

detected in the frame web, doubler,