When did the color orange enter flight test? When did the color orange enter flight test?  As early as the Bell X-1, pictured here, aircraft were painted orange to enhance visibility. Later, in 1959, a study was conducted that suggested the utility of orange markings on aircraft.  In 1968, the Society of Flight Test Engineers adopted a logo with "flight test orange" as its color.



There are, however, few references that explain the following:


When orange flight test equipment (wires, parts, LRUs, etc.) first appeared.  For example, I transcribed a 1977 article from the SFTE's Flight Test News that sets 1949, anecdotally, as the time/event that caused Douglas to use orange wire. But it also references a Mil Spec. (Does anyone know more about the Mil Spec referred to?
When orange flight suits first appeared?
When aircraft (in general) adopted orange paint schemes for flight test aircraft, as seen here?
They were originally used to allow ground spotters to better spot the aircraft from the ground for optical tracking during flight test.  Another use of painting wingtips, tailplanes and tailfins bright colors was to allow observers a better means to determine the aircraft’s orientation and attitude in flight.

Finally if it all went so wrong so fast, hi viz colors made it easier for SAR crews to locate the wreckage....and the remains of the pilot.....quickly.

I know the Navy and the USMC were using orange flight suits as early as the Korean War, not for their test pilots, but for fleet air crews to make it easier for SAR aircraft to locate then in the event of a ditching or bailout over open water.