Complex sentence: Instead of separate levers to control the elevator and ailerons as in his previous aircraft, Sikorsky designed a single control lever with a wheel allowing control of pitch and roll with a button switch to momentarily deactivate the ignition thereby controlling engine power.
Split into simpler sentences: Instead of separate levers to control the elevator and ailerons as in his previous aircraft, Sikorsky designed a single control lever with a wheel allowing control of pitch and roll. This "control column" included a button switch to momentarily deactivate the ignition thereby controlling engine power.