Complex sentence: TKS Ice Protection systems are commonly used as a factory installed or retrofit option on single-engine and twin-engine aircraft, a number of business jet aircraft and military unmanned aerial vehicle applications.
Split into simpler sentences: TKS Ice Protection systems are commonly used as a factory positioned or retrofit alternative on aircrafts with single/twin-engines. Examples of aircrafts with these types of engines are a number of business jet aircraft and military unmanned aerial vehicle applications.