Mooney M20M, Pilot Operating Handbook

Page: 344 / 377

190-02291-18 Rev. 5 AFMS – GFC 500 Mooney M20M/M20R/M20S Series
Page 7–1
SECTION 7 – SYSTEM DESCRIPTION
AFCS OVERVIEW
The GFC 500 is a digital Automatic Flight Control System (AFCS). It is a two-axis autopilot, with optional
3
rd
axis yaw damper, and flight director system which provides the pilot with the following features:
G5 Outputs to Autopilot — The G5 flight instrument (when installed) provides attitude, rate, and
acceleration information to the servos. Additionally, indicated airspeed, vertical speed, pressure altitude
and GPS information are sent to the autopilot for mode control.
G3X Outputs to Autopilot — The G3X electronic flight instrument system provides attitude, rate, and
acceleration information to the servos. Additionally, indicated airspeed, vertical speed, pressure altitude
and GPS information are sent to the autopilot for mode control.
GI 275 Outputs to Autopilot — The GI 275 electronic flight instrument system provides attitude, rate,
and acceleration information to the servos. Additionally, indicated airspeed, vertical speed, pressure
altitude and GPS information are sent to the autopilot for mode control.
Flight Director (FD) — The flight director processing occurs in the G5, GI 275, or G3X instrument.
Selected modes for the flight director are displayed on the G5, GI 275, or G3X autopilot status box.
The flight director provides:
•
Command Bars showing pitch/roll guidance
•
Vertical / lateral mode selection and processing
Autopilot (AP) — Autopilot operation occurs within the pitch, roll, and optional pitch trim servo. It also
provides servo monitoring, and automatic flight control in response to flight director steering commands,
attitude and rate information, and airspeed.
Optional Electric Pitch Trim — The pitch trim servo provides manual electric pitch trim capability when
the autopilot is not engaged. The trim servo provides automatic pitch trim when the autopilot is engaged
and the airplane is in the air. Automatic trim functionality is disabled on the ground.
Optional Yaw Damper (YD) — The yaw servo provides Dutch roll damping and turn coordination in
response to yaw rate, roll angle, lateral acceleration, and airspeed.
GMC 507 — Pilot commands to the autopilot and flight director are entered through the GMC 507
autopilot mode panel. The GMC 507 contains internal sensors which calculate the aircraft attitude,
attitude rate and accelerations. These inertial sensors are completely independent from the sensors
within the G5, GI 275, or G3X and the rest of the autopilot system, and are not used for the flight director,
autopilot, or ESP functions. They are used solely to provide independent monitoring of the GFC 500.
Airspeed and Altitude Information — The GFC 500 requires airspeed and altitude information from the
G5 instrument, the GI 275 system, or the G3X system.
Other components of the AFCS include the GSA 28 pitch, roll, and optional pitch trim servo, optional yaw
servo, that also contain autopilot processors, control wheel mounted elevator trim switch (if trim servo is
installed), control wheel mounted autopilot / yaw damper disconnect and trim interrupt button (AP DISC /
TRIM INT), and a Go-Around (GA) button.
Underspeed Protection (USP) — The GFC 500 will provide Underspeed Protection when the autopilot is
engaged.
When the 69 KIAS is reached, a visual MINSPD message will appear above the airspeed tape and the
autopilot will lower the nose to maintain 69 KIAS. An aural “AIRSPEED, AIRSPEED” voice alert will sound
for installations connected to an audio panel.
Underspeed Protection is exited automatically when airspeed exceeds 74 KIAS.