Write a reply to this with posing one question: Piston-engine aircraft are still used today and still play a significant role in commercial flight training. Piston-engine aircraft are commonly used for flight training due to their low cost, fuel efficiency and simple maintenance. Piston engines are found in small general aviation aircraft like the Cessna 172 Skyhawk which more than 50% of the world's pilots have trained on. The Skyhawk is considered the most successful training aircraft in history with over 44,000 aircraft built since 1956 (Textron Aviation, 2023). A majority of small UAVs and radio-controlled aircraft are piston-engine powered as well (Farokhi, 2021). Piston-engine technology is simpler than modern alternatives and therefore is less capable in comparison to turboprop and jet engines when it comes to speed, altitude, and capacity. Piston engines do offer better fuel efficiency at low altitudes and have lower operating cost. Piston engines do provide sufficient efficiency for short range and low altitude missions to include flight training, recreational flying, and agricultural spraying (Textron Aviation, 2023). For future capabilities of piston-engine aircraft, the implementation of hybrid electric propulsion could be an area of consideration. Hybrid electric propulsion systems combines piston engines and electric motors in order to improve overall efficiency and reduce the emission footprint of the aircraft (Amprius Technologies). Additionally, upgraded ai