A senior Toyota engineer who played a leading role in developing the Prius and was among the top US experts on gasoline-electric hybrid vehicles has died in a plane crash in the Pacific Ocean.

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David Hermance, 59, was piloting an experimental plane when it went down on Saturday afternoon off the California coast.


A search team found the wreckage of the two-passenger Interavia E-3 aircraft submerged in 18 metres of water Sunday morning.


Hermance was executive engineer for Advanced Technology Vehicles at Toyota’s technical centre in the Los Angeles area, company spokesman Mike Michels said.


There, he was key in developing the gas-electric Prius and bringing it to the US market, where it gained popularity for its fuel effeciency.


“He was widely recognized as the most authoritative individual on hybrid power vehicles in the US,” Michels said.


Hermance was believed to be the only person aboard the plane.

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