Leonard Greene, 88, Inventor, Think-Tank Maven

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Leonard Greene, who died November 30 at 88, used his experience as a wartime test pilot to invent the stall detector and other aircraft safety equipment, as well as more curious devices like the audible traffic light and a machine that automatically charges telemarketers for the opportunity to pitch their wares.

Inspired, he said, by observing an earthworm, Greene patented a supersonic plane with a central air intake, a design element he claimed virtually eliminated the sonic boom.

A man of wide interests and deep enthusiasms, Greene founded the libertarian Institute for SocioEconomic Studies to lobby for a favored project that he thought would create an economic renaissance: income tax rebates. He also syndicated a World’s Cup racing yacht, founded an organization that distributed unused seats on corporate jets to needy cancer patients, and set several flight endurance records in his Beach King Air turbo prop.

Forever tinkering, Greene came up with any number of inventions that made little money — an automatic voice translation system for foreign films, an audio method to help the blind to paint. He even held a patent on three-dimensional chess.

Greene was born in New York. The Greenes manufactured rubber cement, but poverty gripped the family during the Depression, and his father died when Leonard was 16. As a student at City College, Greene studied chemistry and engineering, and his first job was as a research chemist at the Rubber & Asbestos Corp. of Jersey City, N.J. At the outbreak of World War II, he went to work as a pilot at the Grumman Aircraft Engineering Corp. in Bethpage, L.I.

In 1946, Greene founded Safe Flight Instrument Corp. of White Plains to manufacture his stall warning indicator. Stalling was at the time one of the most common causes of crashes.

In a story Greene told often, he invented the indicator while at Grumman after he saw a fellow pilot stall and then fatally crash.

“Within milliseconds or nanoseconds, I said, ‘Gee, if a pilot knows that the airplane is going to stall, he would prevent it. He wouldn’t permit it to happen. What you have to do is have something to tell him,'” Greene told Investor’s Business Daily in 1988. He went home and built a simple detector – a kind of electrified weather vane – out of a bicycle buzzer and some metal strips.

The stall detector found a ready market, and eventually became required equipment in all airplanes. In 1947, the Saturday Evening Post called it “the greatest life saver since the invention of the parachute.” In 1948, his company announced it had received more than 30 reports of pilots who had been saved from stalling by the detector.

Safe Flight Instrument also developed a range of other safety devices, including a landing speed indicator and the “stickshaker,” which alerted pilots that planes were in trouble by vibrating the controls. During the 1970s, the company was among the first to develop technology for detecting and reacting to wind shear.

A recreational sailor, Greene developed autopilots for yachts. In the early 1980s, he purchased from Ted Turner the Courageous, a 12-meter yacht Mr. Turner had twice used to defend the cup successfully. He overhauled it and renamed it Courageous IV. Sadly, Greene’s technological fixes backfired, and by the time it was eliminated, detractors snickered that the IV stood for “intravenous.”

Another sideline for Greene was social policy. He was convinced that government tax policies and welfare removed incentives for the poor to work. In 1974, he founded the SocioEconomic Institute, which issued a stream of white papers on such issues. It frequently purchased space on Op-Ed pages to trumpet its libertarian-tinged views. Recently, it has concentrated on opposing national health care and finding alternatives to Social Security.

Greene wrote several books, including “Free Enterprise Without Poverty” (1981) and “The National Tax Rebate: A New America with Less Government” (2000). He also wrote “Inventorship: The Art of Innovation” (2001). He passed on his passion to his grandchildren, some of whom have patent applications of their own for such things as snowboards and a set of binoculars that also works as a camera.

Greene stayed actively involved in his company, which remains privately held, until the end. Much of his effort in recent years was devoted to safety improvements for helicopters, and his most recent patent — the latest of perhaps 200 in all — was granted in August.

His son, Randall Greene, the president of Safe Flight Instrument, also has several aviation patents. Another son who was involved in the business, Donald Greene, was aboard United Flight 93 on September 11, 2001, when the plane was hijacked and eventually crashed into a field near Shanksville, Pa.

Greene was gregarious, although something of the absent-minded professor, his daughter, Bonnie LeVar, says. He was a daredevil behind the wheel, betraying his days as a New York City cab driver, and liked to confound waitresses by ordering a favorite beverage, grapefruit juice with nutmeg and seltzer. To make it right, you had to have another patented Greene invention: nutmeg emulsion.

Leonard Michael Greene
Born June 8, 1918, in New York; died of cancer November 30 at a hospital in White Plains; Greene was once widowed and twice divorced and is survived by 12 children, 17 grandchildren, and six greatgrandchildren.


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