Photograph of two men looking at the door of the Learjet 23 prototype, February 18, 1964. A third man is visible inside the aircraft performing a test with an oscillograph.Inscription on verso: "Direct read out oscillograph loaned from Century…
Photograph of the Learjet 23 prototype undergoing a fuselage down-bending test, February 18, 1964.Text on sign: "Fuselage down bending static test / 0% ultimate / 18 Feb. 1964."Inscription on verso: "T58-2-O / 2-18-64."
Photograph of the Learjet 23 prototype undergoing a fuselage up-bending test, February 13, 1964.Text on sign: "Fuselage up bending static test / 100% ultimate / 13 Feb. 1964."Inscription on verso: "T58-1-C / 2-13-64."
Photograph of people observing a Learjet 23 fuselage undergoing testing in a hydrostatic tank, January 15, 1964. William P. Lear (in vest) is on the left.Typed caption on verso: "Meets FAA requirements: / Both fail-safe and ultimate fatigue tests…
Audio recording of a speech given by William P. Lear at a Lear Jet employee banquet, 1964.
Text on label: "Lear Jet 1964 employee banquet speech. Sept."
Photograph of the Learjet 23 prototype at a Lear facility, September 10, 1963. Other aircraft undergoing construction and testing are visible in the background.Inscription on verso: "P 15-D / Sept. 10, 1963."
Photograph of the Learjet 23 prototype at a Lear facility, September 10, 1963. Other aircraft undergoing construction and testing are visible in the background.Inscription on verso: "P 15-E / Sept. 10, 1963."