12/31/2009. Remarks by Johan Visschedijk: "Although based on the Model 240, the Convair-Liner 340 was largely a new aircraft fitted with a fuselage of the same diameter as that of the 240 but longer with increased seat capacity, port side entry doors, greater wing span and area with additional fuel tanks, more powerful engines, greater all-up weight, taller landing gear, and many interior design improvements. The prototype, c/n 1 (registered N3401) was first flown October 5, 1951, followed by c/n 2 (N73102) on January 18, 1952, and the type received its Type Certificate on March 28, 1952.

C/n 2 (N73102) was delivered to United Air Lines as a Model 340-31 on September 2, 1952. After fourteen years of service it was sold to Frontier Airlines and subsequently converted to a Model 580 by replacing the 2,400 hp Pratt & Whitney R-2800-CBI6 eighteen-cylinder, two-row, air cooled radial engines driving three-blade props with 3,750 shp Allison 501-D13D turboprops with four-blade props, and fitting larger vertical and horizontal tail surfaces.

In May 1979 it was bought by Gem State Airlines (later Golden Gate Airlines) and reregistered N116GS. In February 1984 it was sold to Aspen Airlines, reregistered to N113AP in August 1984. Renown Airlines owned it briefly between March 1991 and December 1991, whereafter it was obtained by Allied Signal in January 1992, who had it reregistered N580AS in November 1992. Since it has been used by Allied Signals/Garrett/Honeywell as an avionics test bed."