[1] The prototype had been ordered by Bill Frutchy of Elmira, New York and the aircraft was available for him to fly it in the second half of the US Nationals.

The success of this aircraft led to more orders and series production was commenced.

[4][5] A 1-23, flown by William Ivans, set a world altitude record for gliders on 30 December 1950, reaching a height of 42,089 ft (12,840 m).

[6] 1-23Ds were flown by Paul McCready to win the 1953 US Nationals and to set a distance record of 455.5 miles (733 km) by Joe Lincoln.

[9] Data from The World's Sailplanes:Die Segelflugzeuge der Welt:Les Planeurs du Monde Volume II[16]General characteristics Performance