[Federal Register Volume 65, Number 116 (Thursday, June 15, 2000)]
[Proposed Rules]
[Pages 37494-37497]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-15189]


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Proposed Rules
                                                Federal Register
________________________________________________________________________

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.

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

[[Page 37494]]



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).

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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

[[Page 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

[[Page 37496]]

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.


Sec. 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.

[[Page 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