Question: In what county is the city that the Synergy Aircraft Synergy designer was from?
Sentence (from "Wittman Regional Airport"): Wittman Regional Airport (IATA: OSH, ICAO: KOSH, FAA LID: OSH) is a county owned public use airport located two nautical miles (4 km) south of the central business district of Oshkosh, a city in Winnebago County, Wisconsin, United States.
Relevant evidence: No