Abstract: An aircraft forwardly propelled by a power plant including a pair of jet engines, is operated in a VTOL mode by powered rotation of a rotary wing mechanically rotoring the engines. When unloaded during fixed wing flight, the power plant is operated in an accelerating rocket mode preceding high speed ram jet operation. Radially extensible blades of the rotary wing vary the mechanical loading on the engines while adjustable chokes at the intake of each engine and in the outlet of a common after-burner for the engines, condition the power plant for its different operational modes.