1. Power and Weight: A 340cc Yamaha engine typically produces around 20 horsepower, which is insufficient power to lift the weight of a helicopter, even an ultralight one. Helicopters require a considerable amount of power to generate lift, and the power-to-weight ratio is critical.
2. Cooling System: Helicopter engines operate under high temperatures and require efficient cooling systems. Yamaha engines are designed for motorcycles, which have different cooling requirements compared to aircraft engines. Modifying the engine for helicopter use would likely be complex and might compromise its reliability.
3. Reliability and Certification: Building an ultralight helicopter from scratch involves stringent safety and certification requirements. Using an engine not specifically designed for aircraft applications raises concerns about reliability, durability, and airworthiness.
4. Propeller and Transmission: Integrating the engine with a propeller and transmission system suitable for helicopter flight is a complex engineering challenge. Matching the engine's output with the propeller's requirements, as well as designing and constructing a reliable transmission system, requires extensive expertise in aeronautical engineering.
5. Control Systems: Helicopter flight controls, including cyclic, collective, and rudder inputs, are critical for safe operation. Integrating these control systems with a modified engine requires specialized knowledge in helicopter flight mechanics and control engineering.
6. Structural Considerations: Building an ultralight helicopter requires careful considerations of weight distribution, structural integrity, and aerodynamics. Modifying an engine for helicopter use may introduce additional stress points and compromise the structural integrity of the aircraft.
Given the complexity and safety considerations involved, it's highly recommended to use an engine specifically designed and certified for ultralight helicopter use. Building a helicopter from scratch requires a high level of expertise in aeronautical engineering, flight dynamics, and safety regulations, and it's not a project to undertake without the necessary knowledge, training, and resources.
