[Federal Register Volume 66, Number 11 (Wednesday, January 17, 2001)]
[Notices]
[Pages 4055-4056]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-1276]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

[Policy Statement Number ACE-00-23.777-01]


Proposed Issuance of Policy Memorandum, Automatic Pilot (Control 
Wheel Steering) Applications for Part 23/CAR 3 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of policy statement; request for comments.

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SUMMARY: This document proposes to adopt new policy for certification 
of normal, utility, acrobatic, and commuter category turbine powered 
airplanes with automatic pilot (autopilot) (control wheel steering) 
applications.

DATES: Comments sent must be received by February 16, 2001.

ADDRESSES: Send all comments on this proposed policy statement to the 
individual identified under FOR FURTHER INFORMATION CONTACT.

FOR FURTHER INFORMATION CONTACT:
    Sending comments: Bill Marshall, Federal Aviation Administration 
(FAA), Small Airplane Directorate, Regulations and Policy Branch, ACE-
111, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone (816) 
329-4116; fax (816) 329-4090; email: [email protected]>.
    Asking technical questions: Jon Hannan, FAA, Small Airplane 
Directorate, Regulations and Policy Branch, ACE-111, 901 Locust, Room 
301, Kansas City, Missouri 64106; telephone (816) 329-4127; fax (816) 
329-4090; email: [email protected]>.

SUPPLEMENTARY INFORMATION:

Comments Invited

    How do I comment on the proposed policy? We invite your comments on 
this proposed policy statement, ACE-00-23.777-01. You may send whatever 
written data, views, or arguments you choose. We will consider all 
comments received by the closing date. We may change the proposals 
contained in this notice because of the comments received.
    Please send comments using the following Internet address: 
[email protected]. Comments sent using the Internet must contain 
``Comments to Policy Statement ACE-00-23.777-01'' in the subject line. 
Writers should format in Microsoft Word 97 or ASCII any file 
attachments that are sent using the Internet.
    Send comments using the following format:
     Organize comments issue-by-issue. For example, discuss a 
comment about the automatic pilot control panel and a comment about 
primary flight controls as two separate issues.
     For each issue, state what specific change you are 
requesting to the proposed policy memorandum.
     Include justification (for example, reasons or data) for 
each request. If sending your comments using the Internet will cause 
you extreme hardship, you may send comments using the U.S. Mail, 
overnight delivery, or facsimile machine. You should mark your 
comments, ``Comments to Policy Statement ACE-00-23.777-01'' and send 
two copies to the above address in the section ``FOR FURTHER 
INFORMATION CONTACT: Sending comments.''
    What would be the general effect of this proposed policy? The FAA 
is

[[Page 4056]]

presenting this information as a set of guidelines suitable for use. 
However, we do not intend for this proposed policy to become a binding 
norm; it does not form a new regulation, and the FAA would not apply or 
rely on it as a regulation.
    The FAA Aircraft Certification Offices (ACO's) and Flight Standards 
District Offices (FSDO's) that certify changes in type design and 
approve alterations in normal, utility, and acrobatic category 
airplanes should try to follow this policy when appropriate. Also, as 
with all advisory material, this statement of policy identifies one 
means, but not the only means, of compliance.
    Because this proposed general statement of policy only announces 
what the FAA seeks to establish as policy, the FAA considers it to be 
an issue for which public comment is appropriate. Therefore, the FAA 
requests comments on the following proposed general statement of policy 
relevant to compliance with Sec. 23.777 of the Federal Aviation 
Regulations (14 CFR 23.777), and other related regulations.

Background

    How does part 23 address the automatic pilot (autopilot) and 
control wheel steering? The guidance on autopilots used in part 23 
airplanes does not specifically address Control Wheel Steering (CWS). 
Before 1996, CWS was a term used by industry to describe a momentary 
autopilot interrupt mode. Holding the CWS switch depressed temporarily 
disconnected the autopilot pitch and roll servos so the airplane could 
be maneuvered. When the CWS switch was released, the autopilot servos 
would reengage in the same mode as previously selected.
    One minor exception was where an autopilot dropped the vertical 
axis from the reengagement. But in no case was there a change to a mode 
that had not been selected.
    What recent developments have led to this proposed policy? More 
recently, there have been some autopilots certificated that could be 
engaged from a CWS mode switch on the primary flight controls. 
Additionally, some autopilots were certificated that changed modes from 
what had been previously selected by depressing the CWS switch.
    In some cases, these two installations could lead to inadvertent 
autopilot engagement or mode changes during critical phases of flight 
such as liftoff, approach, and landing flare. Inadvertent operation 
could then lead to confusion and a misperception of a flight control 
problem or an unintended loss of approach coupling.
    Although not specifically pertinent to autopilot controls, 
Sec. 23.777 of the Federal Aviation Regulations (14 CFR 23.777) 
requires that each cockpit control ``be located . . . to provide 
convenient operation and to prevent confusion and inadvertent 
operation.''

The Proposed Policy

    In order to comply with the intent of Sec. 23.777 of the Federal 
Aviation Regulations (14 CFR 23.777) as applicable to automatic pilots 
(autopilots) installed in part 23 airplanes, autopilots should be 
evaluated in accordance with the following:

    Note: These characteristics are not applicable to ``go around'' 
mode switches which are allowed on throttles.

     The automatic pilot (autopilot) should not be engaged from 
a switch on the primary flight controls, unless that switch is 
protected so inadvertent engagement is not possible. Guards covering 
the switch, which can be moved to provide access to the switch, may be 
acceptable in some cases.
     Mode changes should not be made by using a switch on the 
primary flight controls unless some reliable means is provided to 
prevent unsafe conditions caused by inadvertent mode changes. Refer to 
Sec. 23.1329(h) of the Federal Aviation Regulations (14 CFR 
23.1329(h)).
     The autopilot disengage button should be the color red and 
be of different design from nearby switches so it is distinguishable by 
touch.

    Issued in Kansas City, Missouri on January 2, 2001.
Marvin R. Nuss,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-1276 Filed 1-16-01; 8:45 am]
BILLING CODE 4910-13-U