Garmin GFC 500 Manual page 38

Electronic Stability and Protection (ESP) uses the autopilot servos to assist the pilot in maintaining the airplane in
a safe flight condition within the airplane's normal pitch, roll and airspeed envelopes.
Electronic Stability and Protection is invoked when the pilot allows the airplane to exceed one or more conditions
beyond normal flight defined below:
•
Pitch attitude beyond normal flight (+20°, -15°)
•
Roll attitude beyond normal flight (45°)
•
High airspeed beyond normal flight (above 176 KIAS)
•
Low airspeed below normal flight (below 60 KIAS)
The conditions that are required for ESP to be available are:
•
Pitch and Roll servos available
•
Autopilot not engaged
•
The GPS altitude above ground is more than 200 feet (for low airspeed mode)
•
Aircraft is within the autopilot engagement envelope (+/-50° in pitch and +/-75° in roll)
Protection for excessive Pitch, Roll, and Airspeed is provided when the limit thresholds are first exceeded, which
engages the appropriate servo in ESP mode at a nominal torque level to bring the airplane back within the normal
flight envelope. If the airplane deviates further from the normal flight envelope, the servo torque will increase
until the maximum torque level is reached in an attempt to return the airplane into the normal flight envelope.
Once the airplane returns to within the normal flight envelope, ESP will deactivate the autopilot servos.
When the normal flight envelope thresholds have been exceeded for more than 10 seconds, ESP Autolevel Mode
is activated. Autolevel Mode engages the autopilot to bring the airplane back into straight and level flight based
on 0° roll angle and 0 FPM vertical speed. An aural "ENGAGING AUTOPILOT" alert (or a Sonalert tone) sounds
and the Flight Director mode annunciation will indicate LVL for the pitch and roll modes.
Anytime an ESP mode is active, the pilot can interrupt ESP by using the Autopilot Disconnect (AP DISC / TRIM
INT) switch, or simply override ESP by overpowering the autopilot servos. The pilot may also disable ESP
through the G5 menu.
The engagement and disengagement attitude limits are displayed with double hash marks on the roll indicator
depending on the airplane attitude and whether or not ESP is active in roll. When ESP is inactive (roll attitude
within nominal limits) only the engagement limit indications are displayed in order to reduce clutter on the roll
indicator.
Display symbology implemented for ESP is illustrated in the following figures.
AFMS – GFC 500 Autopilot in Textron 182 Series
Page 7–2
190-02291-06 Rev. 2