[Federal Register Volume 63, Number 78 (Thursday, April 23, 1998)]
[Rules and Regulations]
[Pages 20064-20066]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-10918]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-124-AD; Amendment 39-10497; AD 98-09-16]
RIN 2120-AA64
Airworthiness Directives; Aerospatiale Model ATR-42 and ATR-72
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 all Aerospatiale Model ATR-42 and ATR-72 series
airplanes. This action requires revising the Airplane Flight Manual
(AFM) to add specific flightcrew instructions to be followed in the
event of failure of one or both of the direct current (DC) generators.
This amendment is prompted by issuance of mandatory continuing
airworthiness information by a foreign civil airworthiness authority.
The actions specified in this AD are intended to prevent failure of the
second of two DC generators after the failure of the first generator,
which could lead to the loss of main battery power and result in the
loss of all electrical power, except the emergency battery supply,
during flight.
DATES: Effective May 8, 1998.
Comments for inclusion in the Rules Docket must be received on or
before May 26, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 98-NM-124-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056.
Information pertaining to this amendment may be obtained from or
examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue,
SW., Renton, Washington.
FOR FURTHER INFORMATION CONTACT: Norman B. Martenson, Manager,
International Branch, ANM-116, FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)
227-2110; fax (425) 227-1149.
SUPPLEMENTARY INFORMATION: The Direction Generale de l'Aviation Civile
(DGAC), which is the airworthiness authority for France, recently
notified the FAA that an unsafe condition may exist on all Aerospatiale
Model ATR-42 and ATR-72 series airplanes. The DGAC advises that an ATR
airplane experienced the loss of the number one direct current (DC)
generator, followed by the loss of the number two DC generator, during
flight. The loss of the second generator occurred following an attempt
by the flightcrew to reset the number one generator, in accordance with
approved procedures. After a few minutes, the airplane experienced the
loss of main battery power. The cause of the failure of the second
generator is currently under investigation. Such failures, if not
corrected, could result in the loss of all electrical power, except the
emergency battery supply, during flight.
French Airworthiness Directives
The DGAC issued French telegraphic airworthiness directives T98-
148-076(B) and T98-149-038(B), both dated March 20, 1998, in order to
assure the continued airworthiness of these airplanes in France. These
French airworthiness directives require adherence to instructions
specified in ATR AFM Chapter 5-04 in the event of one DC generator
failure, and specify that no attempt should be made to reset the
affected DC generator. Additionally, the French airworthiness
directives note that, in the event of failure of both DC generators,
resetting the generators should be attempted.
Explanation of FAA's Findings
The current version of the FAA-approved ATR Airplane Flight Manual
(AFM) specifies that a single failed generator is to be left in the
``OFF'' position; however, the AFM does not explicitly prohibit an
attempted reset of a failed generator. Moreover, for some operators,
Flight Crew Operating Manuals may contain instructions for one attempt
to reset a failed generator. Therefore, the FAA has determined that
explicit instructions must be provided in the Limitations section of
the AFM to specify that flight crews should not attempt to reset a
single failed generator. However, in the event of dual DC generator
failure, reset of the generators should be attempted.
FAA's Conclusions
These airplane models are manufactured in France and are type
certificated for operation in the United States under the provisions of
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and
the applicable bilateral airworthiness agreement. Pursuant to this
bilateral airworthiness agreement, the DGAC has kept the FAA informed
of the situation described above. The FAA has
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examined the findings of the DGAC, reviewed all available information,
and determined that AD action is necessary for products of this type
design that are certificated for operation in the United States.
Explanation of Requirements of Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other airplanes of the same type design registered
in the United States, this AD is being issued to prevent failure of the
second of two DC generators after the failure of the first generator,
which could lead to the loss of main battery power and result in the
loss of all electrical power, except the emergency battery supply,
during flight. This AD requires revising the Limitations Section of the
AFM to add specific flightcrew instructions to be followed in the event
of failure of one or both of DC generators.
Interim Action
This is considered to be interim action. The manufacturer has
advised the FAA that it is currently investigating the cause of the
dual generator failure and may develop a modification that will
positively address the unsafe condition in this AD. Once the
investigation is concluded, the FAA may consider further rulemaking.
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 98-NM-124-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, Safety.
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:
98-09-16 Aerospatiale: Amendment 39-10497. Docket 98-NM-124-AD.
Applicability: All Model ATR-42 and ATR-72 series airplanes,
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 (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 failure of the second of two direct current (DC)
generators after the failure of the first generator, which could
lead to the loss of main battery power and result in the loss of all
electrical power, except the emergency battery supply, during
flight, accomplish the following:
(a) Within 10 flight hours after the effective date of this AD,
revise the Limitations Section of the FAA-approved Airplane Flight
Manual (AFM) to include the following statements. This action may be
accomplished by inserting a copy of this AD into the AFM.
`` In the event of failure of either DC generator during
flight, do not attempt to reset the affected DC generator.
In the event of failure of both DC generators during
flight, one attempt to reset each of the generators may be made, as
follows:
--If the first attempt to reset a generator is successful, do not
attempt to reset the other generator.
--If the first attempt to reset a generator is not successful, one
attempt to reset the other generator may be made.
--If neither attempt to reset the generators is successful, land at
the nearest suitable airport.''
(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, International Branch, ANM-116, FAA,
Transport Airplane Directorate. Operators shall submit their
requests through an appropriate FAA Principal Maintenance Inspector,
who may add comments and then
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send it to the Manager, International Branch, ANM-116.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the International Branch, ANM-116.
(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.
Note 3: The subject of this AD is addressed French telegraphic
airworthiness directives T98-148-076(B) and T98-149-038(B), both
dated March 20, 1998.
(d) This amendment becomes effective on May 8, 1998.
Issued in Renton, Washington, on April 20, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-10918 Filed 4-22-98; 8:45 am]
BILLING CODE 4910-13-U