After graduation, Heintz served in the
Armée de l'Air and went on to find employment with
Aerospatiale, on the
Concorde supersonic airliner project. Later, he worked for
Avions Pierre Robin designing several two-seat and four-seat
light aircraft for
type certification and production, including the
Robin HR100 and
Robin HR200. After introducing a series of designs based on the CH200, he designed the
Zenith STOL CH 701 and the
Zenair CH 601 Zodiac. The CH701 design led to the larger two-seat
Zenith STOL CH 750 and the four-seat
Zenith STOL CH 801. The US-based
Zenith Aircraft Company was started by his son, Sebastien Heintz in
Mexico, Missouri in 1992. Zenith is licensed to produce the range of Heintz-designed kit aircraft, with a focus on the US
light-sport aircraft category. The
Zenith CH 2000 was type certified in 1996 and a company,
Aircraft Manufacturing and Design started by Heintz in
Eastman, Georgia, to produce it as the
AMD Alarus. Later a kit version, the
Zenair CH 640 was produced. During a number of successive exhibitions at
AirVenture in
Oshkosh, Wisconsin, Heintz organized building a complete aircraft during the seven day event. Typical was the 2014 plan to assemble a
Zenair CH 750, using volunteer labour from show attendees, enlisting 7,000 people to pull one rivet each to complete the project in an estimated 170 hours of building, before the aircraft flew on the last day of the show. More than 10,000 examples of his aircraft designs have been completed and flown. Heintz also conducted consulting engineering work and was involved with
Transport Canada in the development of Canadian regulations for
amateur-built aircraft and
advanced ultralight aircraft. He also worked on the regulations for the US light-sport aircraft category. He was a popular public speaker, speaking at AirVenture and
Sun 'n Fun among other venues, on the subjects of aircraft design, aircraft homebuilding and regulations. ==Retirement and death==