[Federal Register Volume 59, Number 205 (Tuesday, October 25, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-26240]


[[Page Unknown]]

[Federal Register: October 25, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-CE-21-AD; Amendment 39-9051; AD 94-22-02]

 

Airworthiness Directives; Consolidated Aeronautics Lake Model 250 
Airplanes Equipped With a Bendix/King KFC 150 Automatic Flight Control 
System

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 
applies to Consolidated Aeronautics Lake Model 250 airplanes equipped 
with a Bendix/King KFC 150 automatic flight control system. This action 
requires pulling the ``A/P'' and ``TRIM'' circuit breakers, and 
fabricating and installing a placard that specifies the use of manual 
trim only. An incident where the elevator trim spring lever of a Lake 
Model 250 airplane failed to return to neutral following KFC 150 
automatic flight control system autotrim operation prompted this 
action. The resulting mistrim overpowered the autopilot and caused the 
airplane to deviate from its flight path. The actions specified by this 
AD are intended to prevent automatic flight control system malfunctions 
caused by failure of the elevator autotrim to disengage, which could 
result in flight path deviations.

DATES: Effective November 4, 1994.
    Comments for inclusion in the Rules Docket must be received on or 
before December 30, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Assistant Chief 
Counsel, Attention: Rules Docket 94-CE-21-AD, Room 1558, 601 E. 12th 
Street, Kansas City, Missouri 64106.
    Information that relates to this AD may be examined at the Federal 
Aviation Administration (FAA), Central Region, Office of the Assistant 
Chief Counsel, Attention: Rules Docket 94-CE-21-AD, Room 1558, 601 E. 
12th Street, Kansas City, Missouri 64106.

FOR FURTHER INFORMATION CONTACT: Mr. Roger A. Souter, Aerospace 
Engineer, Wichita Aircraft Certification Office, 1801 Airport Road, 
Room 100, Mid-Continent Airport, Wichita, Kansas 67209; telephone (316) 
946-4134; facsimile (316) 946-4407.

SUPPLEMENTARY INFORMATION: The FAA has received a report where the 
Bendix/King KFC 150 automatic flight control system malfunctioned 
because the elevator trim spring lever on a Consolidated Aeronautics 
Lake Model 250 airplane failed to return to neutral following KFC 150 
automatic flight control system autotrim operation. This resulted in 
the airplane deviating from its flight path.
    This KFC 150 automatic flight control system incorporates a 
mechanical attachment to the basic airplane's trim system; the basic 
airplane in turn has a pilot-actuated spring-loaded lever that controls 
a hydraulic actuator. During the original type certification efforts of 
the KFC 150 automatic flight control system, a modification was 
incorporated that prevents the engage solenoid for the elevator 
autotrim servo from remaining occasionally engaged because of an 
opposing forced created by the spring. The modification provided a 
design where the spring would back-drive the servo motor, relieve the 
spring tension, and allow the solenoid to disengage; the solenoid 
engages once autotrim begins to run, and disengages when autotrim stops 
running.
    In the referenced incident, the spring lever of the airplane failed 
to return to neutral and the pitch trim continued to run while the KFC 
150 automatic flight control system was on autopilot with autotrim 
operation. The resulting mistrim overpowered the autopilot and caused 
the airplane to deviate from the flight path. The pilot recognized the 
problem, disengaged the autopilot, and took control of the airplane. 
Initial investigation of the incident reveals that the elevator 
autotrim servo did not disengage because of the loads imposed by the 
basic airplane's spring lever.
    While testing and additional investigation continues in developing 
a modification to solve this problem, the FAA has determined that, in 
the interim, this Bendix/King KFC 150 automatic flight control system 
should not be utilized on Consolidated Aeronautics Lake Model 250 
airplanes.
    After examining the circumstances and reviewing all available 
information related to the incidents described above, the FAA has 
determined that AD action should be taken in order to prevent automatic 
flight control system malfunctions caused by failure of the elevator 
autotrim to disengage, which could result in flight path deviations.
    Since an unsafe condition has been identified that is likely to 
exist or develop in other Consolidated Aeronautics Lake Model 250 
airplanes of the same type design that are equipped with a Bendix/King 
KFC 150 automatic flight control system, this AD requires pulling the 
``A/P'' and ``TRIM'' circuit breakers, and fabricating and installing a 
placard that specifies the use of manual trim only.
    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for public 
prior 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 immediate flight safety and, thus, was not 
preceded by notice and opportunity to 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 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 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 notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket No. 94-CE-21-AD.'' The postcard will be date stamped and 
returned to the commenter.
    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 and that must be issued immediately to correct an unsafe 
condition in aircraft, and 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 (otherwise, an evaluation is 
not required). A copy of it, if filed, may be obtained from the Rules 
Docket.

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. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding a new airworthiness directive 
to read as follows:

94-22-02 Consolidated Aeronautics: Amendment 39-9051; Docket No. 94-
CE-21-AD.

    Applicability: Lake Model 250 airplanes (all serial numbers), 
certificated in any category, that are equipped with a Bendix/King 
KFC 150 automatic flight control system.
    Compliance: Required within the next 10 hours time-in-service 
after the effective date of this AD, unless already accomplished.
    To prevent automatic flight control system malfunctions caused 
by failure of the elevator autotrim to disengage, which could result 
in flight path deviations, accomplish the following:
    (a) Pull the two circuit breakers, one marked ``A/P'' and the 
other marked ``TRIM'', and attach a collar or tie-wrap to them to 
prevent resetting.
    (b) Fabricate a placard with the words: ``Use manual trim 
only.'', and install this placard on the instrument panel within the 
pilot's clear view.
    (c) Special flight permits may be issued in accordance with 
Secs. 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) An alternative method of compliance or adjustment of the 
initial or repetitive compliance times that provides an equivalent 
level of safety may be approved by the Manager, Wichita Aircraft 
Certification Office (ACO), 1801 Airport Road, Room 100, Mid-
Continent Airport, Wichita, Kansas 67209. The request shall be 
forwarded through an appropriate FAA Maintenance Inspector, who may 
add comments and then send it to the Manager, Wichita ACO.

    Note: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Wichita ACO.

    (e) Information related to this AD may be examined at the FAA, 
Central Region, Office of the Assistant Chief Counsel, Room 1558, 
601 E. 12th Street, Kansas City, Missouri 64106.
    (f) This amendment (39-9051) becomes effective on November 4, 
1994.

    Issued in Kansas City, Missouri, on October 18, 1994.
John R. Colomy,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-26240 Filed 10-24-94; 8:45 am]
BILLING CODE 4910-13-U