[Federal Register Volume 61, Number 111 (Friday, June 7, 1996)]
[Proposed Rules]
[Pages 29038-29039]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-14384]
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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. 61, No. 111 / Friday, June 7, 1996 / Proposed
Rules
[[Page 29038]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 96-NM-06-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 737-100 and -200 Series
Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to certain Boeing Model 737-100 and -
200 series airplanes. This proposal would require replacement of the
250 volt-ampere (VA) rated static inverters with 410 or 500 VA rated
static inverters, and an operational test of the standby electrical
power system. This proposal is prompted by a report that accomplishment
of a certain modification could result in overload of the static
inverter on these airplanes. The actions specified by the proposed AD
are intended to prevent overload of the static inverter, which could
result in the loss of the 115 volt alternating current standby bus and
the associated flight instruments when the airplane is operating on
standby electrical power.
DATES: Comments must be received by July 19, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 96-NM-06-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: Stephen Oshiro, 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 (206) 227-2793; fax (206)
227-1181.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of the
proposed rule by submitting such written data, views, or arguments as
they may desire. Communications shall identify the Rules Docket number
and be submitted in triplicate to the address specified above. All
communications received on or before the closing date for comments,
specified above, will be considered before taking action on the
proposed rule. The proposals contained in this notice may be changed in
light of the comments received.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the proposed rule. All
comments submitted will be available, both before and after the closing
date for comments, in the Rules Docket for examination by interested
persons. A report summarizing each FAA-public contact concerned with
the substance of this proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 96-NM-06-AD.'' The postcard will be date stamped and
returned to the commenter.
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, Transport Airplane Directorate, ANM-103, Attention: Rules
Docket No. 96-NM-06-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The FAA has received a report indicating that, during an
engineering review of Revision 4 to Boeing Service Bulletin 737-24-1051
by the manufacturer, it was found that the effectivity listing of the
original issue through Revision 4 of this service bulletin included
some Boeing Model 737-100 and -200 series airplanes equipped with 250
volt-ampere (VA)-rated static inverters. That particular static
inverter may overload on these airplanes if the modification described
in these particular revisions of the service bulletin has been
accomplished. The modification entails revising the power connections
to the captain's instrument panel. Such an overload on the static
inverters could result in the loss of the 115 VAC standby bus and the
associated flight instruments when the airplane is operating on standby
electric power. Loss of use of these components may adversely affect
the handling characteristics of the airplane.
FAA's Conclusions
Based on the information obtained from the manufacturer's review,
the FAA finds that static inverters rated at 410 VA or 500 VA can
safely handle the increase in electrical loading of the 115 VAC standby
bus when the modification specified in Service Bulletin 737-24-1051
(the original issue through Revision 4) is accomplished. Therefore, the
FAA has determined that replacement of 250 VA-rated static inverters
with 410 VA or 500 VA-rated static inverters will positively address
the identified unsafe condition.
Explanation of Requirements of Proposed Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other products of this same type design, the
proposed AD would require replacement of the 250 VA-rated static
inverters with certain 410 or 500 VA-rated static inverters. This
replacement would be required only on those airplanes on which the
modification specified in the various revisions of Boeing Service
Bulletin 737-24-1051 has been accomplished.
After accomplishment of the replacement, the proposed AD would also
require performing an operational test of the standby electrical power
system.
[[Page 29039]]
The proposed actions would be required to be accomplished in
accordance with the Boeing 737 Airplane Maintenance Manual.
Cost Impact
There are approximately 51 Boeing Model 737-100 and -200 series
airplanes of the affected design in the worldwide fleet. The FAA
estimates that 1 airplane of U.S. registry would be affected by this
proposed AD, that it would take approximately 2 work hours per airplane
to accomplish the proposed actions, and that the average labor rate is
$60 per work hour. Required parts would cost approximately $10,500 per
airplane. Based on these figures, the cost impact of the proposed AD on
U.S. operators is estimated to be $10,620.
The cost impact figure discussed above is based on assumptions that
no operator has yet accomplished any of the proposed requirements of
this AD action, and that no operator would accomplish those actions in
the future if this AD were not adopted.
Regulatory Impact
The regulations proposed herein would not have substantial direct
effects on the States, on the relationship between the national
government and the States, or on the distribution of power and
responsibilities among the various levels of government. Therefore, in
accordance with Executive Order 12612, it is determined that this
proposal would not have sufficient federalism implications to warrant
the preparation of a Federalism Assessment.
For the reasons discussed above, I certify that this proposed
regulation (1) is not a ``significant regulatory action'' under
Executive Order 12866; (2) is not a ``significant rule'' under the DOT
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979);
and (3) if promulgated, will not have a significant economic impact,
positive or negative, on a substantial number of small entities under
the criteria of the Regulatory Flexibility Act. A copy of the draft
regulatory evaluation prepared for this action is contained in the
Rules Docket. A copy of it may be obtained by contacting the Rules
Docket at the location provided under the caption ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
part 39 of the Federal Aviation Regulations (14 CFR part 39) as
follows:
PART 39--AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
Boeing: Docket 96-NM-06-AD.
Applicability: Model 737-100 and -200 series airplanes; equipped
with 250 volt-ampere (VA) rated static inverters; on which the
modification specified in Boeing Service Bulletin 737-24-1051
(original issue, dated October 20, 1988; Revision 1, dated October
5, 1989; Revision 2, dated June 28, 1990; Revision 3, dated May 7,
1992; or Revision 4, dated December 21, 1995) has been accomplished;
certificated in any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
otherwise modified, altered, or repaired in the area subject to the
requirements of this AD. For airplanes that have been modified,
altered, or repaired so that the performance of the requirements of
this AD is affected, the owner/operator must request approval for an
alternative method of compliance in accordance with paragraph (b) of
this AD. The request should include an assessment of the effect of
the modification, alteration, or repair on the unsafe condition
addressed by this AD; and, if the unsafe condition has not been
eliminated, the request should include specific proposed actions to
address it.
Compliance: Required as indicated, unless accomplished
previously.
To prevent overload of the static inverter, which could result
in the loss of the 115 VAC standby power and the associated flight
instruments, accomplish the following:
(a) Within 10 months after the effective date of this AD,
replace the 250 VA rated static inverters either with 500 VA-rated
static inverters having Boeing part number (P/N) 60B40023-2, or with
410 VA-rated static inverters having Jet Electronics and Technology
P/N 3S2060DV109B1, in accordance with Section 20-10-111 of the
Boeing 737 Airplane Maintenance Manual. Prior to further flight
following the replacement, perform an operational test of the
standby electrical power system in accordance with Section 24-54-0
of the Boeing 737 Airplane Maintenance Manual.
Note 2: Replacements and operational tests accomplished prior to
the effective date of this amendment in accordance with Boeing Alert
Service Bulletin 737-24A2113, dated February 29, 1996, are
considered acceptable for compliance with this AD.
(b) An alternative method of compliance or adjustment of the
compliance time that provides an acceptable level of safety may be
used if approved by the Manager, Seattle Aircraft Certification
Office (ACO), FAA, Transport Airplane Directorate. Operators shall
submit their requests through an appropriate FAA Principal
Maintenance Inspector, who may add comments and then send it to the
Manager, Seattle ACO.
Note 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
(c) Special flight permits may be issued in accordance with
sections 21.197 and 21.199 of the Federal Aviation Regulations (14
CFR 21.197 and 21.199) to operate the airplane to a location where
the requirements of this AD can be accomplished.
Issued in Renton, Washington, on June 3, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-14384 Filed 6-6-96; 8:45 am]
BILLING CODE 4910-13-U
