François Hussenot: Flight Data Recorder

The pilot and manufacturer Colonel François Hussenot was a French engineer who was responsible for inventing the first flight recorder back in the late 1930s. The celebrated “black box” was manufactured by Sagem which got later acquired by Safran Electronics & Defense in 2005.

François Hussenot began his career in 1935 as a test engineer at the Centre d’Essais de Matériels Aériens (CEMA) in Villacoublay, then at the Centre d’Essais en Vol (CEV) in Marignane. He specialized in studying, manufacturing, and fine-tuning flight test instrumentation. In 1939, he designed a flight data recorder using photographs. Named the “Hussenographe”, it is considered to be the forerunner of modern black boxes.

Unlike modern recorders, Hussenot’s early models had the particularity of storing the information not on a magnetic band, but on an eight-meter-long by 88 mm wide photographic film, scrolling in front of a thin spot of light deviated by a mirror to represent the data. The initials HB stood for Hussenot and Beaudouin, the name of an early associate who helped Hussenot in developing the device during World War II. Those flight recorders were also known as “Hussenographs”.

He became Director of Methods at the Flight Test Center in Brétigny-sur-Orge, and co-founded both the French National Test Pilot School (École du Personnel Navigant, now the EPNER) and the Measuring Instruments Manufacturing Company (Société de Fabrication d’Instruments de Mesure). François Hussenot later received the Aeronautics Medal. He died at 39 in a test flight crash.

Good to know

The “black box” isn’t black. It’s orange. Before airlines made that color standard for their flight recorders, some Boeings used a yellow sphere, and the British had a gizmo called the Red Egg. So why do they call it “black”? One explanation goes this way: In 1939, an aviation engineer named François Hussenot devised a means of capturing an aircraft’s history to a box of photographic film. Onboard sensors flashed into the box through calibrated mirrors and traced a running tab of flight parameters, including altitude, airspeed, and the position of the cockpit controls. Because the device worked like a camera, its insides had to be in total darkness; thus, perhaps, the “black” -ness of the box.