CHAPTER XXII – Flying Machines Construction And Operation

In his lecture to the Royal Society of Arts, F. W. Lanchester discussed the complexities of aerial flight, emphasizing that practical flight is a matter of locomotive engineering rather than abstract theory. He criticized the helicopter or vertical screw type for its inefficiency in transport, asserting that only airplanes could meet the demands of locomotion by achieving necessary speeds to counter wind velocities and ensuring fuel economy for longer flights.

Lanchester highlighted the necessity for an airplane to compete with other forms of locomotion by being able to navigate efficiently against air currents, which necessitates a velocity greater than that of the strongest winds. He illustrated this point with diagrams showing how an airplane’s movement is hampered by increasing wind speeds, noting that to counteract this, airplanes must achieve high speeds, thus demanding more fuel. The optimal speed for an airplane, he argued, was over 60 miles per hour to combat gusts and ensure rapid damping to stabilize the flight path – a speed already achieved by pioneers like the Wright brothers and Farman.

On the technical side, Lanchester detailed the limitations imposed by fuel consumption on flight range and duration. He pointed out the importance of developing lightweight engines with low fuel consumption rates to enable longer flights without significantly increasing the total weight of the aircraft. He presented data on the weight-to-power ratios of contemporary engines, indicating the progress and challenges in aviation engineering.

Propulsion efficiency was another crucial topic Lanchester tackled. He advocated for the use of screw propellers, which, like their marine counterparts, required careful consideration of diameter, pitch, and position relative to the aircraft to optimize efficiency. By using curves to represent the efficiency of propeller blades, he demonstrated how to determine the best design for an aircraft’s propulsion system, favoring propellers positioned at the rear of the aircraft to avoid disrupting airflow and to utilize energy from the wake current.

Finally, Lanchester touched on the potential benefits of soaring flight, which reduces the power needed by utilizing upward air currents found near cliffs or generated by temperature differences. He cited examples from nature, such as the soaring behavior of condors and gulls, to illustrate how aircraft might one day harness similar principles to improve efficiency in flight.