A single-engine Cessna with a red cross on its side circles low in the dawn glare over Loliondo, a village of thatched-roof mud huts in northern Tanzania. Scores of zebra scatter into the thorn bushes as the pilot, a bulky, blue-eyed man with a deep tan, sets the plane down on a dusty airstrip. As it taxis to a halt, a group of Masai carrying long-bladed, lion killing spears rush up shouting "Soba"—"welcome." Dr. Michael Wood is making a house call.

Wood, 57, is the co-founder, director and chief surgeon of the Nairobi-based East African Flying Doctor Service, which for 20 years has provided medical care to the bush country of Kenya, Uganda and Tanzania. Wood has a staff of 60 working out of a modern two-story building next to the Nairobi airport, but still spends much time in the field and performs 500 operations a year himself, some of them in torchlit huts.

Such dedication has earned him the gratitude of thousands of East Africans, from villagers who have nicknamed Wood "doctor with wings" to Kenya President Jomo Kenyatta, whose government contributes $50,000 to the FDS every year.

Ironically, Wood came to Africa in the first place because of his own poor health. Born in Guildford, Surrey, he trained as a plastic surgeon in London during World War II. When asthma forced him to seek a drier climate, his wife, whose family once had lived in East Africa, suggested Kenya. The Woods moved there after the war.

Practicing in Nairobi, Wood often met with Sir Archibald McIndoe, a noted British plastic surgeon and Africa enthusiast, who encouraged him to organize a mobile medical service. With Tom Rees, an American doctor he had met in Britain, Wood began the service in 1957, making the early runs alone in a secondhand plane. Rees, now a prominent New York plastic surgeon, is board chairman of the affiliated International Medical and Research Foundation. Dr. Wood still practices some plastic surgery in Nairobi and turns his fees over to the foundation.

The FDS—which has built up a fleet of eight planes—has flown 3.5 million miles and treated 400,000 sick or injured people. Wood himself has taken care of such celebrities as Ernest Hemingway (for plane crash injuries), Walter Cronkite's vacationing son Chip (for appendicitis) and an influential Masai warrior who made Wood a blood brother after recovering from a spear wound.

Dr. Wood long ago came to regard Kenya as home. His four children were all born there, and he and his wife live in a rambling stucco house in the Nairobi suburb of Karen. The only hobby he ever had was a weekend farm in Tanzania, but his small plot was taken over by the government during a land reform program.

During the recent quick trip to Loliondo—on a day when he had also scheduled operations on three children 110 miles away in Nairobi—Wood toured the village hospital to check victims of intestinal diseases. He set dates for surgery on an old man who had broken his arm falling down a well and a Masai leader bitten on the thigh while defending his cows against a lion. Wood also began plans to fit a 12-year-old herd boy with an artificial left foot. The boy's own had been amputated after he was bitten by a black mamba snake.

"In the old days, this kid would never have seen a doctor," Wood said. "He wouldn't have had a chance."