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What percentage can Friction HP reach of the indicated HP on a modern aircraft engine?

  1. 5-10%

  2. 10-15%

  3. 15-20%

  4. 20-25%

The correct answer is: 10-15%

In modern aircraft engines, friction horsepower (HP) can reach about 10-15% of indicated horsepower (IHP). This percentage represents the power that is lost due to internal friction within the engine components, including the moving parts like pistons, camshafts, and bearings. Understanding this percentage is crucial for evaluating the overall efficiency of an engine. Indicated horsepower is a measure of the engine's output before losses are accounted for, while friction horsepower quantifies those inefficiencies. In contemporary designs, advancements in materials and engineering have minimized friction losses, allowing the friction horsepower to stay within this range rather than exceeding it. This knowledge helps engineers and technicians assess engine performance and make necessary adjustments or improvements to enhance efficiency and reduce wear over time.