[Federal Register Volume 62, Number 72 (Tuesday, April 15, 1997)]
[Proposed Rules]
[Pages 18304-18306]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-9593]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-36-AD]
RIN 2120-AA64


Airworthiness Directives; de Havilland Model DHC-7 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 all de Havilland Model DHC-7 
series airplanes. This proposal would require revising the Airplane 
Flight Manual (AFM) to prohibit positioning of the power levers below 
the flight idle stop while the airplane is in flight, and to provide a 
statement of the consequences of positioning the power levers below the 
flight idle stop. This proposal is prompted by incidents and accidents

[[Page 18305]]

involving airplanes equipped with turboprop engines in which the 
propeller beta was used improperly during flight. The actions specified 
by the proposed 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.

DATES: Comments must be received by May 23, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 97-NM-36-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.

FOR FURTHER INFORMATION CONTACT: Peter LeVoci, Aerospace Engineer, 
Systems and Flight Test Branch, ANE-172, FAA, New York Aircraft 
Certification Office, Engine and Propeller Directorate, 10 Fifth 
Street, Third Floor, Valley Stream, New York 11581; telephone (516) 
256-7514; fax (516) 568-2716.

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 97-NM-36-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. 97-NM-36-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    In recent years, the FAA has received reports of 14 incidents and/
or accidents involving intentional or inadvertent operation of the 
propellers in the beta range during flight on airplanes equipped with 
turboprop engines. (Beta is the range of propeller operation intended 
for use during taxi, ground idle, or reverse operations as controlled 
by the power lever settings aft of the flight idle stop.)
    Five of the fourteen in-flight beta occurrences were classified as 
accidents. In each of these five cases, operation of the propellers in 
the beta range occurred while the airplane was in flight. Operation of 
the propellers in the beta range during flight, if not prevented, could 
result in loss of airplane controllability, or engine overspeed with 
consequent loss of engine power.
    Communication between the FAA and the public during a meeting held 
on June 11-12, 1996, in Seattle, Washington, revealed a lack of 
consistency of the information on in-flight beta operation contained in 
the FAA-approved Airplane Flight Manual (AFM) for airplanes that are 
not certificated for in-flight operation with the power levers below 
the flight idle stop. (Airplanes that are certificated for this type of 
operation are not affected by the above-referenced conditions.)

FAA's Determinations

    The FAA has examined the circumstances and reviewed all available 
information related to the incidents and accidents described 
previously. The FAA finds that the Limitations Section of the AFM's for 
certain airplanes must be revised to prohibit positioning the power 
levers below the flight idle stop while the airplane is in flight, and 
to provide a statement of the consequences of positioning the power 
levers below the flight idle stop. The FAA has determined that the 
affected airplanes include those that are equipped with turboprop 
engines and that are not certificated for in-flight operation with the 
power levers below the flight idle stop. Since de Havilland Model DHC-7 
series airplanes meet these criteria, the FAA finds that the AFM for 
these airplanes must be revised to include the limitation and statement 
of consequences described previously.

U.S. Type Certification of the Airplane

    This airplane model is manufactured in Canada and is 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. The FAA has 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 the Requirements of the Proposed AD

    Since an unsafe condition has been identified that is likely to 
exist or develop in other de Havilland Model DHC-7 series airplanes of 
the same type design, the proposed AD would require revising the 
Limitations Section of the AFM to prohibit positioning the power levers 
below the flight idle stop while the airplane is in flight, and to 
provide a statement of the consequences of positioning the power levers 
below the flight idle stop while the airplane is in flight.

Interim Action

    This is considered interim action until final action is identified, 
at which time the FAA may consider further rulemaking.

Cost Impact

    The FAA estimates that 45 de Havilland Model DHC-7 series airplanes 
of U.S. registry would be affected by this proposed AD, that it would 
take approximately 1 work hour per airplane to accomplish the proposed 
actions, and that the average labor rate is $60 per work hour. Based on 
these figures, the cost impact of the proposed AD on U.S. operators is 
estimated to be $2,700, or $60 per airplane.
    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

[[Page 18306]]

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:

De Havilland, Inc.: Docket 97-NM-36-AD.

    Applicability: All Model DHC-7 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.

    ``Positioning of power levers below the flight idle stop while 
the airplane is in flight is prohibited. Such positioning may lead 
to loss of airplane control or may result in an 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, New York Aircraft Certification 
Office (ACO), FAA, Engine and Propeller Directorate. Operators shall 
submit their requests through an appropriate FAA Maintenance 
Operations Inspector, who may add comments and then send it to the 
Manager, New York ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the New York 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 April 8, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-9593 Filed 4-14-97; 8:45 am]
BILLING CODE 4910-13-U