Charles Ellington graduated at Duke University, North Carolina, and came to Cambridge in 1973 to work for a PhD on insect flight dynamics. He developed novel methodology and software for the kinematic analysis of freely hovering insects and applied them to his own high-speed films of a range of species. He identified five new non-steady-state mechanisms for lift generation, was the first to develop a vortex theory for flapping flight and developed and extended the use of morphometric parameters in calculating the forces and power requirements of flight. He remained in Cambridge, married a colleague, joined the staff of the Department of Zoology, became a fellow of Downing College and continued to work on insect aerodynamics and energetics, publishing on flight muscle efficiency, the factors limiting flight performance and the aerodynamic implications of the origin of insect flight. Building a closed-circuit wind tunnel connected with a sensitive oxygen analyser, he studied with colleagues how the aerodynamics and metabolic power input of bumblebees vary with flight speed, challenging the orthodox theory that this should follow a U-shaped curve. Outstanding among later research was the discovery that hawkmoths, and by implication many other insects, gain high levels of lift by generating a vortex above the leading edge, stabilized by spiralling out along the span—a major focus of animal flight research ever since. His many administrative roles included editorship of theJournal of Experimental Biology. He became a British citizen in 1995, was elected FRS in 1998 and to a chair of animal mechanics in 1999. Awards include the Scientific Medal of the Zoological Society and the University of Cambridge Pilkington Prize for teaching excellence. He was diabetic throughout his adult life, and suffered progressive ill health following a heart attack in 1996. He took early retirement in 2010, lived quietly with his wife and two sons at home near Newmarket, and died in July 2019.
AN EVALUATION OF THE “RAPOX” RAPID RESPONSE PARAMAGNETIC OXYGEN ANALYSER
