[Learjet 23 aircraft under construction in Lear's Wichita facility]

Photograph of three Learjet 23 aircraft (visible tail number N801L) under construction in Lear's Wichita facility, Kansas, February 24 1964.

Typed caption on verso: "[letterhead: 'Lear Jet Corporation / Photo Release'] / 24 February 1964 / For immediate release / Progress at Lear Jet's Wichita Plant: / Number Three airframe (center foreground) is having engines and instrumentation installed prior to roll-out, which is expected by February 26th. This aircraft will then support Number One (right background) in the flight test program. / Number One has logged 100 hours during 80 test flights since its first flight in early last October. / The static airframe, Number Two, (seen in left background) has now completed exhaustive fatigue test on empennage as well as undergoing hydrostatic pressurization tests. / After being cycled 20,000 times at 8.8 psi, cabin construction was proved conclusively on a fail-safe basis beyond 18 psi ultimate pressurization load. / The empennage was also proven fail-safe after being subjected to an unprecedented 460,000 unsymmetrical gust cycles. / Forward and aft portions of Number Four fuselage (not shown) were mated to empennage earlier this month."