These pilots also commented that control seemed almost normal and that, aside from the brief lateral acceleration immediately after making a track change, they could not tell whether the engines were providing all of the flight control. All pilots found the FCP knobs very easy and natural to use. Observers sitting in the cabin noted no difference from a normal approach unless seated where they could hear the engine sounds changing pitch. Conceptually, a very good idea. This demonstration effectively shows the potential for practical implementation.
More work is needed in order to move to the regulatory credit stage.
Pilotage with manual throttle consistently induced both phugoid and dutch roll tendencies. The insertion of PCA damped these modes out. The PCA is an enhancing characteristic and will increase the level of safety of the aircraft. This technology should be further developed. I had trouble flying manual with throttles only for pitch and roll.