[Learjet 23 aircraft during flight test at Lear facility]

Photograph of a Learjet 23 aircraft (tail number N801L) during a flight test at a Lear facility, January 1964. Details about the aircraft and its flight tests are provided in the caption.

Typed caption on verso: "Fifty-Hour Milestone: Latest photo of Lear Jet being put through its paces for recent high-speed tests and flutter analysis during which it logged 50th hour. / The maximum level-flight speed is expected to be .9 Mach with cruise speed between .8 to .84 Mach at 90 to 93% RPM. (The fuel flow is 1500 pounds-per-hour at 560 MPH and 35,000 ft. altitude.) / Fully loaded, the sleek twin-jet climbs to 40,000 feet in just 10 and one-quarter minutes. / Henry G. Beaird, chief of flight test engineering, reports that the Lear Jet stalls at amazingly low speeds and handles beautifully with complete lateral control. / 'It can be flown right out of a stall by simply increasing thrust,' he added. Two-G turns have also been made at 40,000 feet without stall or buffet. / No flame-outs have been encountered in high and low altitude stalls to date. / Beaird has found that variable dive-flaps can provide a maximum decent under emergency conditions from a 40,000 ft. altitude at a rate of 18,000 feet per minute at .8 Mach. / Note drogue safety chute on platform aft fuselage. Woolen tufts on wing area are for air-flow observation. (Lear Jet --- 15 January 1964."