[Federal Register Volume 64, Number 169 (Wednesday, September 1, 1999)]
[Rules and Regulations]
[Pages 47653-47656]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-22532]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NM-111-AD; Amendment 39-11282; AD 99-18-16]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747-400, 757-200, 767-200,
and 767-300 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This amendment adopts a new airworthiness directive (AD) that
is applicable to certain Boeing Model 747-400, 757-200, 767-200, and
767-300 series airplanes. This action 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. This AD also provides for
an optional terminating action for the repetitive checks and tests.
This amendment is prompted by a report of a MAWEA power supply failure
due to inadequate over-voltage protection. The actions specified in
this 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.
DATES: Effective September 16, 1999.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of September 16, 1999.
Comments for inclusion in the Rules Docket must be received on or
before November 1, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 99-NM-
[[Page 47654]]
111-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.
The service information referenced in this AD 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; or at
the Office of the Federal Register, 800 North Capitol Street, NW.,
suite 700, Washington, DC.
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: The FAA has received a report that, during a
production flight test of a Boeing Model 747-400 series airplane, the
flight test group noticed a power supply failure on the status page of
the engine indication and crew alerting system (EICAS). Investigation
revealed that the automated bench test procedure for the modular
avionic warning electronic assembly (MAWEA) overstressed the 5.7 volt
over-voltage clamp circuit which resulted in the failure of the circuit
to protect the warning cards in the MAWEA. A slow failure of the MAWEA
power supply could result in the gradual degradation of available
visual, aural, and tactile alerts. Absence of such alerts could result
in the flightcrew not being aware and not taking immediate or
appropriate action in the event of an unsafe condition (i.e., a fire,
overspeed condition, autopilot disconnect, stall, not in takeoff
configuration, or landing gear not extended).
The warning electronic unit (WEU) power supply units on certain
Boeing 757-200, 767-200, and 767-300 series airplanes are identical to
those on the MAWEA power supply on the affected Boeing Model 747-400
series airplanes. Therefore, all of these airplanes may be subject to
the same unsafe condition.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Service Bulletins 747-31-
2288, dated December 17, 1998, and Revision 1, dated January 28, 1999
(for Model 747-400 series airplanes); 757-31-0066, Revision 1, dated
December 17, 1998 (for Model 757-200 series airplanes); and 767-31-
0106, Revision 1, dated December 17, 1998 (for Model 767-200 and 767-
300 series airplanes). These service bulletins describe procedures for
replacement (including system functional tests) of the MAWEA or WEU
power supply with a new power supply.
Explanation of the Requirements of the Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other Boeing Model 747-400, 757-200, 767-200, and
767-300 series airplanes of the same type design, this AD is being
issued to detect and correct failure of the MAWEA or WEU, which could
result in loss of any visual, aural, or tactile alert to the flightcrew
when an unsafe condition exists. This AD requires repetitive checks of
the status page on the EICAS display system for any MAWEA or WEU
failure; repetitive system functional tests to detect the loss of any
visual, aural, or tactile alert; and replacement of the MAWEA or WEU
power supply with a new power supply, if necessary. This AD also
provides for an optional terminating action for the repetitive checks
and functional tests. The replacement, if accomplished, shall be
accomplished in accordance with the service bulletins described
previously.
Interim Action
This is considered to be interim action. The FAA may consider
further rulemaking action to require the accomplishment of the optional
terminating action currently specified in this AD. However, the
proposed compliance time for accomplishment of that action is
sufficiently long so that prior notice and time for public comment will
be practicable.
Determination of Rule's Effective Date
Since a situation exists that requires the immediate adoption of
this regulation, it is found that notice and opportunity for prior
public comment hereon are impracticable, and that good cause exists for
making this amendment effective in less than 30 days.
Comments Invited
Although this action is in the form of a final rule that involves
requirements affecting flight safety and, thus, was not preceded by
notice and an opportunity for public comment, comments are invited on
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All
communications received on or before the closing date for comments will
be considered, and this rule may be amended in light of the comments
received. Factual information that supports the commenter's ideas and
suggestions is extremely helpful in evaluating the effectiveness of the
AD action and determining whether additional rulemaking action would be
needed.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the rule that might
suggest a need to modify the 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 that
summarizes each FAA-public contact concerned with the substance of this
AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this rule must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 99-NM-111-AD.'' The postcard will be date stamped and
returned to the commenter.
Regulatory Impact
The regulations adopted herein will 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 final
rule does not have sufficient federalism implications to warrant the
preparation of a Federalism Assessment.
The FAA has determined that this regulation is an emergency
regulation that must be issued immediately to correct an unsafe
condition in aircraft, and that it is not a ``significant regulatory
action'' under Executive Order 12866. It has been determined further
that this action involves an emergency regulation under DOT Regulatory
Policies and Procedures (44 FR 11034, February 26, 1979). If it is
determined that this emergency regulation otherwise would be
significant under DOT Regulatory Policies and Procedures, a final
regulatory evaluation will be prepared and placed in the Rules Docket.
A copy of it, if filed, may be obtained from the Rules Docket at the
location provided under the caption ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
[[Page 47655]]
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration amends 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:
99-18-16 Boeing: Amendment 39-11282. Docket 99-NM-111-AD.
Applicability: Model 747-400 series airplanes, line numbers 1121
through 1177 inclusive; Model 757-200 series airplanes, line numbers
761 through 828 inclusive; and Model 767-200 and 767-3300 series
airplanes, line numbers 668 through 723 inclusive; equipped with
either a modular avionics warning electronic assembly (MAWEA) or a
warning electronics unit (WEU) power supply, part number 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 (f) 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 failure of the MAWEA or WEU, which could
result in a gradual degradation and eventual loss of visual, aural,
or tactile alerts to the flightcrew, accomplish the following:
Model 747-400 Series Airplanes: Checks and Functional Tests
(a) For Model 747-400 series airplanes: Within 15 days after the
effective date of this AD, check the status page of the engine
indication and crew alerting system (EICAS) for any MAWEA failure;
and perform the system functional tests required by paragraphs
(a)(1), (a)(2), (a)(3), (a)(4), and (a)(5) of this AD to detect loss
of any visual, aural, or tactile alert. Thereafter, repeat the EICAS
status page check and the system functional tests before each
flight.
Note 2: The following tests are an abbreviated version of
Section 3, Work Instructions, of Boeing Service Bulletin 747-31-
2288, dated December 17, 1998, and Revision 1, dated January 28,
1999.
(1) Perform a takeoff (T/O) configuration warning test to check
the T/O configuration warning card, master monitors A and B, and
left and right aural synthesizer cards.
(i) Set the parking brake.
(ii) Initiate the following central maintenance computer (CMC)
ground test--31 indication/recording: T/O warning.
(iii) Verify that the left and right master warning lights (MWL)
illuminate and the siren is heard from both the left and right
speakers.
(2) Perform an altitude alert test to check the crew alert
module.
(i) Verify the parking brake is still set.
(ii) Set the selected altitude on the mode control panel (MCP)
to approximately 400 feet above the current altitude.
(iii) Verify that the box around the current altitude on the
altitude tape becomes bright white.
(iv) Set the selected altitude on the MCP to 10,000 feet.
(v) Verify the aural warning owl is not activated.
(3) Perform a stall warning test to check the left and right
stall management module cards.
(i) Ensure that the air data computers (ADC) are operational.
(ii) Initiate the following CMC ground test--27 stall warning:
Left.
(iii) Verify that both stick shakers activate.
(iv) Initiate the following CMC ground test--27 stall warning:
Right.
(v) Verify that both stick shakers activate.
(4) Perform an autopilot (A/P) disconnect test to check the left
and right clacker wailer card.
(i) Press and hold the A/P disconnect on either control wheel.
(ii) Verify the wailer aural is heard over the left and right
speakers and MWL's.
(iii) Release the A/P disconnect switch.
(5) Perform a MAWEA card light emitting diode (LED) test per
Airplane Maintenance Manual (AMM) task 31-51-00-715-014, ``MAWEA
operational test,'' to verify that no red LED on the MAWEA circuit
cards illuminate.
Note 3: The EICAS status page check and the system functional
tests are considered maintenance functions that require airplane log
book entree and maintenance release prior to flight.
Model 757-200, 767-200, and 767-300 Series Airplanes: Checks and
Functional Tests
(b) For Model 757-200, 767-200, and 767-300 series airplanes:
Within 15 days after the effective date of this AD, 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 (for Model 757-200
series airplanes); or Boeing Service Bulletin 767-31-0106, Revision
1, dated December 17, 1998 (for Model 767-200 and 767-300 series
airplanes); as applicable; to detect loss of any visual, aural, or
tactile alert. Thereafter, repeat the EICAS status page check and
the Work Instructions in Section 3, Part 1 of the applicable service
bulletin before each flight.
Note 4: The EICAS status page check and performance of the Work
Instructions in Section 3, Part 1, of the applicable service
bulletin are considered maintenance functions that require airplane
log book entree and maintenance release prior to flight.
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, replace the power supply of the MAWEA or WEU with a
new power supply, 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 (for Model 747-400 series
airplanes); 757-31-0066, Revision 1, dated December 17, 1998 (for
Model 757-200 series airplanes); or 767-31-0106, Revision 1, dated
December 17, 1998 (for Model 767-200 and 767-300 series airplanes);
as applicable. Accomplishment of this action constitutes terminating
action for the repetitive inspection requirements of this AD.
Note 5: 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.
Spares
(d) As of the effective date of this AD, no person shall install
a MAWEA or WEU power supply, part number 285T0035-201, on any
airplane.
Optional Terminating Action
(e) Replacement of the power supply of the MAWEA or WEU with a
new power supply, P/N 285T0035-202 Mod A, in accordance with Boeing
Service Bulletin 747-31-2288, dated December 17, 1998, or Revision
1, dated January 28, 1999 (for Model 747-400 series airplanes); 757-
31-0066, Revision 1, dated December 17, 1998 (for Model 757-200
series airplanes); or 767-31-0106, Revision 1, dated December 17,
1998 (for Model 767-200 and 767-300 series airplanes); as
applicable; constitutes terminating action for the repetitive system
functional tests and EICAS status page checks required by this AD.
Alternative Methods of Compliance
(f) 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 6: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Manager, Seattle ACO.
[[Page 47656]]
Special Flight Permits
(g) 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.
Incorporation by Reference
(h) The replacement, if accomplished, shall be done in
accordance with Boeing Service Bulletin 747-31-2288, dated December
17, 1998, or Boeing Service Bulletin 747-31-2288, Revision 1, dated
January 28, 1999; Boeing Service Bulletin 757-31-0066, Revision 1,
dated December 17, 1998; or Boeing Service Bulletin 767-31-0106,
Revision 1, dated December 17, 1998; as applicable. This
incorporation by reference was approved by the Director of the
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part
51. Copies may be obtained from Boeing Commercial Airplane Group,
P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be
inspected at the FAA, Transport Airplane Directorate, 1601 Lind
Avenue, SW., Renton, Washington; or at the Office of the Federal
Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
(i) This amendment becomes effective on September 16, 1999.
Issued in Renton, Washington, on August 24, 1999.
Vi L. Lipski,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-22532 Filed 8-31-99; 8:45 am]
BILLING CODE 4910-13-P
