Fifteen Hours on a Tightrope
THE FAI RC duration record is the ultimate test of model aircraft reliability and economy. Can a big plane be made strong, yet light enough to carry adequate fuel within the FAI 11-pound limit? Can an engine fly this heavy plane for ten to 20 minutes on each fluid ounce of fuel? Will it keep running for hour after hour, in climb and dive, in changing temperature and
Power & Torque
THERE IS a widespread uneasiness among modelers about the difference between torque and power. Most of us have come across the school definitions: torque is a force applied about a lever arm, and power is the time rate of doing work. These definitions are correct, but they are inadequate to clarify the practical meaning of how the terms apply to model aircraft propulsion. The following experience may help to clear things up. The relation between torque and power was illustrated vividly for me some time ago. While driving uphill in the Blue Ridge Mountains my weak clutch began to slip when the accelerator was pressed hard enough to maintain speed in fourth gear. But in third gear, the car could maintain speed and even accelerate slowly. Thinking about this, I realized that the clutch slipped when too much twisting force, torque, was applied. Yet in third gear the car could accelerate using less torque from the engine.
