The Lockheed Martin A-4AR Fightinghawk is a major upgrade of the McDonnell Douglas A-4M Skyhawk attack aircraft developed for the Argentine Air Force which entered service in 1998. The program was named Fightinghawk in recognition of the F-16 Fighting Falcon, which was the source of its new avionics.
The thermal efficiency is expressed mathematically as:
where:
- is the thermal efficiency,
- is the thrust produced by the engine,
- is the jet velocity,
- ṁf is the mass flow rate of fuel,
- is the specific enthalpy of the fuel.