This is an excerpt from a very interesting article you should fully read over at FlyingMag. Below are quick highlights.
What is this voodoo? I’d been glancing outside the airplane,
I looked down just in time to see the power lever advancing from the idle position to max continuous takeoff thrust, which on this day was a little more than halfway to the forward stops. Seeing the autothrottles in action on a business jet or airliner is no big deal, but in a PC-12 powered by a Pratt & Whitney PT6A lacking full-authority digital engine control, that lever shouldn’t move by itself. It was like a ghost was in our presence — a decidedly friendly ghost, I had to admit.
For nearly the next two hours of flying, including climbs, cruise flight, descents and required navigation performance (RNP) precision instrument approaches, neither Smedberg nor I adjusted the power lever or touched the yokes. Occasional button pressing and knob twisting, plus radio calls and the requisite scans for traffic on this VFR day, were about the only duties necessary for the human pilots on the round-robin demonstration flight across central New Jersey. It wasn’t until we were on final approach for landing back at Morristown Municipal Airport that Smedberg clicked off the autothrottle at 500 feet and took manual control from the unseen computerized apparition that had been working furiously — and flawlessly, I must report — behind the scenes to keep us perfectly on speed, course and altitude throughout our time aloft.
Smedberg says the autothrottle can be adapted to virtually any PT6A-powered airplane by adding the ISU standby display, which operates the thrust computer software that makes the autothrottle function. Testing of ThrustSense aboard a King Air 200 is well underway. IS&S and Blackhawk Modifications have already announced an agreement for Blackhawk to distribute and install IS&S’s NextGen flight deck and integrated turboprop autothrottle system for King Air 200s and 350s — and for good reason. The two models account for more than 3,000 airplanes, according to IS&S, and there are another 2,000 C90 through E90 and F90 King Air models that are candidates for the upgrades as well.
The King Air NextGen flight deck will be similar to the STC’d PC-12 avionics upgrade, but in the twin-PT6A King Air applications, the autothrottle will include engine-out thrust control, which in case of engine failure automatically sets the remaining engine to the correct power level if airspeed drops below minimum controllable airspeed. The idea is that the pilot can maintain control as the autothrottle works to mitigate adverse yaw, allowing the airplane to safely accelerate under full control.
Read the full details over at FlyingMag.