But for simpler applications, including aircraft without autopilots and even for those equipped with rate-based autopilots (which rely on the turn coordinator
), we think the Sandia Quatro is the model to beat.
Other basic models include the panel-mounted System 40 and 50, using a separate turn coordinator
However, many GA autopilots are driven by the panel's turn coordinator
. What then?
Avidyne retained the hidden turn coordinator
from the original S-TEC installation as a fault comparator.
This is easily measured by the inclinometer in a turn coordinator
or turn-and-bank indicator.
Electrical failure could kill the turn coordinator
, autopilot and, most importantly, the com radios and GPS navigator.
These rate-based systems use a custom turn coordinator
to drive the roll axis of the aircraft.
Typically, they get data from a turn coordinator
and an altitude sensor.
He pointed to the AI as level but also saw the turn coordinator
in a turn.
That meant that Cirrus (as well as Columbia, Piper and anyone else who used the Avidyne system) hid an electric turn coordinator
behind the panel and used it to drive the S-Tec 55X rate-based autopilot.
The pilot had to first process the information it received from the attitude indicator, altimeter, airspeed indicator, directional gyro/horizontal situation indicator, turn coordinator
and vertical speed indicator through her vision, compare it with navigational information and develop, on her own, a three-dimensional picture of where the airplane was in space-time.
When autopilots act up, most owners fail to realize that an attitude gyro, flight director or turn coordinator
could be the culprit.