I’ve spent some more time lately flying our Skylane with the Garmin GFC 700 autopilot (or automatic flight control system, as they call it). The smallest change to the system – new autopilot and trim servos – winds up having the largest impact in the real IFR environment. Where the Bendix/King KAP 140 was a rate-based system and didn’t have the precision to command rapid pitch or roll inputs, the Garmin uses the G1000’s own ADC/AHRS to figure out if the airplane is where it needs to be. The higher precision means that it also can react much faster.
When trying to fly an ILS with the ‘old’ system, lowering flaps at the final approach fix or glideslope intercept would cause the autopilot to balloon above and loudly complain “TRIM IN MOTION”. The newer system rapidly (and silently!) counters the pitching moment caused by the flap deployment, precisely intercepting the glideslope at speed and nailing it all the way down to minimums. Being able to fly an approach at 100 knots with 20° of flaps works wonders when it comes to slowing down the very fast new 182T after breaking out on final. I can’t even imagine the hard time guys flying the turbo models must have had with the older autopilot.
When you add in some of the latest G1000 upgrades, like a Decision Altitude bug for approaches and, in the installations with the Garmin autopilot, the addition of a TOGA (Take-Off / Go-Around) button by the throttle, what you get is a complete avionics suite that is continuously evolving and – finally – decreasing pilot workload.