Thrust comes from a propellor or jet which works by causing air to accelerate (i.e. it adds momentum to a mass of air)
Ok so would this be more correct: The engine burns fuel and a percentage of the energy from this process is used by the propeller to give air momentum and as an equal and opposite reaction the aircraft moves fwd.
Theoretically with a wing of infinite span and non viscous incompressible flow there will be no drag due to there being no shear forces and pressure forces balancing out. In this way couldn't you say that lift is proportional to the energy imparted to the airflow as a consequence of the propeller.
Obviously for a real flow there is drag, but still
doesn't the energy for lift still come from the engine? 