[Federal Register Volume 63, Number 204 (Thursday, October 22, 1998)]
[Proposed Rules]
[Pages 56582-56584]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-28276]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-CE-10-AD]
RIN 2120-AA64


Airworthiness Directives; de Havilland Inc. Models DHC-6-1, DHC-
6-100, DHC-6-200, and DHC-6-300 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to adopt a new airworthiness directive 
(AD) that would apply to all de Havilland Inc. Models DHC-6-1, DHC-6-
100, DHC-6-200, and DHC-6-300 airplanes. The proposed AD would require 
amending the Limitations Section of the airplane flight manual (AFM) to 
prohibit the positioning of the power levers aft of the flight idle 
stop while the airplane is in flight. This AFM amendment would include 
a statement of consequences if the limitation is not followed. The 
proposed AD is a result of numerous incidents and five documented 
accidents involving airplanes equipped with turboprop engines where the 
propeller beta was improperly utilized during flight. None of the 
incidents or accidents involved de Havilland Inc. Models DHC-6-1, DHC-
6-100, DHC-6-200, and DHC-6-300 airplanes. The actions specified by the 
proposed AD are intended to prevent loss of airplane control or engine 
overspeed with consequent loss of engine power caused by the power 
levers being positioned aft of the flight idle stop while the airplane 
is in flight.

DATES: Comments must be received on or before December 22, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Regional Counsel, 
Attention: Rules Docket No. 97-CE-10-AD, Room 1558, 601 E. 12th Street, 
Kansas City, Missouri 64106. Comments may be inspected at this location 
between 8 a.m. and 4 p.m., Monday through Friday, holidays excepted.

FOR FURTHER INFORMATION CONTACT: Peter LeVoci, Flight Test Pilot, New 
York Aircraft Certification Office, FAA, 10 Fifth Street, Third Floor, 
Valley Stream, New York 11581; telephone: (516) 256-7536; facsimile: 
(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 should 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 that summarizes 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 No. 97-CE-10-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, Central Region, Office of the Regional Counsel, Attention: 
Rules Docket No. 97-CE-10-AD, Room 1558, 601 E. 12th Street, Kansas 
City, Missouri 64106.

Discussion

    The FAA has received reports of 14 occurrences in recent years of 
incidents or accidents on airplanes equipped with turboprop engines 
related to intentional or inadvertent operation of the propellers in 
the beta range during flight. 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. 
None of the incidents or accidents involved de Havilland Inc. Models 
DHC-6-1, DHC-6-100, DHC-6-200, and DHC-6-300 airplanes.
    Of the 14 documented in-flight beta occurrences, five were 
classified as accidents. In-flight beta operation results that preceded 
the accidents can be classified in one of two categories: (1) Permanent 
engine damage and total loss of thrust on all engines when the 
propellers that were operating in the beta range drove their respective 
engines to overspeed; and (2) loss of airplane control because at least 
one propeller operated in the beta range during flight.
    The most recent accident occurred when both engines of a Saab Model 
340B permanently lost power after eight seconds of beta range propeller 
operation. The propellers consequently drove the engines into 
overspeed, which resulted in internal engine failure.
    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 airplane flight manual (AFM) for airplanes not certificated for in-
flight operation with the power levers aft of the flight idle stop. 
Airplanes that are certificated for this type of operation are not 
affected by the above-referenced conditions.

The FAA's Determination

    After examining the circumstances and reviewing all available 
information related to the incidents and accidents referenced above, 
the FAA has determined that:
    All airplanes equipped with turboprop engines (provided the 
airplane is not certificated for in-flight operation with the power 
levers aft of the flight idle stop) should have information in the 
Limitations Section of the AFM that prohibits positioning of power 
levers aft of the flight idle stop while the airplane is in flight, 
including

[[Page 56583]]

a statement of consequence if the limitation is not followed; and
    Because de Havilland Inc. Models DHC-6-1, DHC-6-100, DHC-6-200, and 
DHC-6-300 airplanes are equipped with turboprop engines, are not 
certificated for in-flight operation with the power levers aft of the 
flight idle stop, and do not contain information in the Limitations 
Section of the AFM that prohibits and explains the consequences of such 
operation, AD action should be taken. The proposed AD is intended to 
prevent loss of airplane control or engine overspeed with consequent 
loss of engine power caused by the power levers being positioned aft of 
the flight idle stop while the airplane is in flight.

Explanation of Provisions of the Proposed AD

    Since an unsafe condition has been identified that is likely to 
exist or develop on other de Havilland Models DHC-6-1, DHC-6-100, DHC-
6-200, and DHC-6-300 airplanes of the same type design, the FAA is 
proposing AD action. The proposed AD would require amending the 
Limitations Section of the AFM to prohibit the positioning of the power 
levers aft of the flight idle stop while the airplane is in flight, 
including a statement of consequences if the limitation is not 
followed. This AFM amendment shall consist of the following language:

    Positioning of power levers aft of 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.

Compliance Time of the Proposed AD

    The FAA has determined that the compliance time of the proposed AD 
should be specified in calendar time instead of hours time-in-service. 
While the condition addressed by the proposed AD is unsafe while the 
airplane is in flight, the condition is not a result of repetitive 
airplane operation; the potential of the unsafe condition occurring is 
the same on the first flight as it is for subsequent flights. The 
proposed compliance time of ``30 days after the effective date of this 
AD'' would not inadvertently ground airplanes and would assure that all 
owners/operators of the affected airplanes accomplish the proposed 
action in a reasonable time period.

Cost Impact

    The FAA estimates that 114 airplanes in the U.S. registry would be 
affected by the proposed AD, that it would take approximately 1 
workhour per airplane to incorporate the proposed AFM amendment, and 
that the average labor rate is approximately $60 an hour. Since an 
owner/operator who holds at least a private pilot's certificate as 
authorized by sections 43.7 and 43.9 of the Federal Aviation 
Regulations (14 CFR 43.7 and 43.9) can accomplish the proposed action, 
the only cost impact upon the public is the time it would take the 
affected airplane owners/operators to amend the AFM.

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 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) 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 has been placed 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 a new airworthiness directive 
(AD) to read as follows:

De Havilland Inc: Docket No. 97-CE-10-AD.

    Applicability: Models DHC-6-1, DHC-6-100, DHC-6-200, and DHC-6-
300 airplanes (all serial numbers), 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 (e) 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 within the next 30 days after the effective 
date of this AD, unless already accomplished.
    To prevent loss of airplane control or engine overspeed with 
consequent loss of engine power caused by the power levers being 
positioned aft of the flight idle stop while the airplane is in 
flight, accomplish the following:
    (a) Amend the Limitations Section of the airplane flight manual 
(AFM) by inserting the following language:

Positioning of power levers aft of 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) This action may be accomplished by incorporating a copy of 
this AD into the Limitations Section of the AFM.
    (c) Amending the AFM, as required by this AD, may be performed 
by the owner/operator holding at least a private pilot certificate 
as authorized by section 43.7 of the Federal Aviation Regulations 
(14 CFR 43.7), and must be entered into the aircraft records showing 
compliance with this AD in accordance with section 43.9 of the 
Federal Aviation Regulations (14 CFR 43.9).
    (d) 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.
    (e) An alternative method of compliance or adjustment of the 
compliance time that provides an equivalent level of safety may be 
approved by the Manager, Systems and Flight Test Branch, FAA, Engine 
and Propeller Directorate, New York Aircraft Certification Office, 
10 Fifth Street, Third Floor, Valley Stream, New York 1158. The 
request shall be forwarded through an appropriate FAA Maintenance 
Inspector, who may add comments and then send it to the Manager, New 
York Aircraft Certification Office.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the New York Aircraft Certification Office.

    (f) All persons affected by this directive may examine 
information related to this AD

[[Page 56584]]

at the FAA, Central Region, Office of the Regional Counsel, Room 
1558, 601 E. 12th Street, Kansas City, Missouri 64106.

    Issued in Kansas City, Missouri, on October 14, 1998.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 98-28276 Filed 10-21-98; 8:45 am]
BILLING CODE 4910-13-U