Airworthiness Directives; Aerospatiale Model ATR-42 and ATR-72 Series Airplanes

[Federal Register Volume 63, Number 61 (Tuesday, March 31, 1998)]
[Rules and Regulations]
[Pages 15285-15286]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-8347]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-228-AD; Amendment 39-10413; AD 98-06-34]
RIN 2120-AA64


Airworthiness Directives; Aerospatiale Model ATR-42 and ATR-72 
Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to all Aerospatiale Model ATR-42 and ATR-72 series 
airplanes, that requires revising the Airplane Flight Manual (AFM) to 
modify the limitation that prohibits positioning the power levers below 
the flight idle stop during flight, and to provide a statement of the 
consequences of positioning the power levers below the flight idle stop 
during flight. This amendment is prompted by incidents and accidents 
involving airplanes equipped with turboprop engines in which the ground 
propeller beta range was used improperly during flight. The actions 
specified by this AD are intended to prevent loss of airplane 
controllability, or engine overspeed and consequent loss of engine 
power caused by the power levers being positioned below the flight idle 
stop while the airplane is in flight.

EFFECTIVE DATE: May 5, 1998.

ADDRESSES: Information pertaining to this amendment may be obtained 
from or examined at the Federal Aviation Administration (FAA), 
Transport Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.

FOR FURTHER INFORMATION CONTACT: Mark Quam, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue SW., Renton, Washington 98055-4056; telephone (425) 
227-2145; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to all Aerospatiale Model ATR-42 and 
ATR-72 series airplanes was published in the Federal Register on 
December 9, 1997 (62 FR 64787). That action proposed to require 
revision of the Limitations Section of the AFM to modify the limitation 
that prohibits the positioning of the power levers below the flight 
idle stop while the airplane is in flight, and to add a statement of 
the consequences of positioning the power levers below the flight idle 
stop while the airplane is in flight.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    One commenter, the manufacturer, requests that the proposed rule 
not be issued specifically against Model ATR airplanes. The commenter 
states that ATR models already have a ``warning'' regarding failure of 
the electro-mechanical gate device. The manufacturer points out that 
the ``warning'' contains specific wording that was presented to the FAA 
during the public meeting held on June 11-12, 1996, in Seattle, 
Washington. The commenter also states that the proposal appears to 
indicate that ATR models are particularly affected by the identified 
unsafe condition. The commenter disagrees, and adds that the in-service 
experience of these models does not warrant an AD.
    The FAA does not concur. The FAA finds that the AFM limitation 
required by this AD is necessary to prohibit positioning the power 
levers below the flight idle stop during flight, regardless of the 
protective features and warnings provided in the design of the affected 
airplanes. Additionally, although none of the accidents and incidents 
referenced in the preamble of the proposal involved Model ATR 
airplanes, the FAA has determined that AD action must be taken against 
all turbopropeller-powered airplanes (regardless of the design features 
of the airplane) that are not approved for operation in the beta range 
during flight. The FAA finds that revising the AFM to prohibit 
operation below the flight idle stop in flight is necessary in order to 
correct the identified unsafe condition. The appropriate vehicle for 
mandating such a requirement is an AD.
    This same commenter requests that the wording of the AFM revision 
that was specified in the proposed rule be revised to reflect the 
wording of the current AFM revision. The commenter points out that the 
wording of the proposed AFM change and the wording of the current AFM 
revision are similar, and that the technical contents are equivalent.
    The FAA concurs with the commenter that the wording specified in 
the proposal is similar to the wording of the current AFM change, and 
that the technical contents are equivalent. Therefore, the FAA has 
revised

[[Page 15286]]

paragraph (a) of the final rule to remove the proposed AFM wording and 
has inserted the current AFM change.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the change previously 
described. The FAA has determined that this change will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    The FAA estimates that 144 Aerospatiale Model ATR-42 and ATR-72 
series airplanes of U.S. registry will be affected by this AD, that it 
will take approximately 1 work hour per airplane to accomplish the 
required actions, and that the average labor rate is $60 per work hour. 
Based on these figures, the cost impact of the AD on U.S. operators is 
estimated to be $8,640, or $60 per airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the 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 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.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it 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:

98-06-34  Aerospatiale: Amendment 39-10413. Docket 97-NM-228-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 loss of airplane controllability, or engine overspeed 
and consequent loss of engine power caused by the power levers being 
positioned below the flight idle stop while the airplane is in 
flight, accomplish the following:
    (a) Within 30 days 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.
    ``Limitation under Flight Operation: ATR airplanes are protected 
against a positioning of power levers below the flight idle stop in 
flight by an IDLE GATE device. It is reminded that any attempt to 
override this protection is prohibited. Such positioning may lead to 
loss of airplane control or may result in an engine overspeed 
condition and consequent loss of engine power.''
    (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, Standardization Branch, ANM-113, 
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, 
Standardization Branch, ANM-113.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (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.
    (d) This amendment becomes effective on May 5, 1998.

    Issued in Renton, Washington, on March 12, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-8347 Filed 3-30-98; 8:45 am]
BILLING CODE 4910-13-U

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