Whilst I hate to revive an old thread, but I felt this was an important one to revive. The Convair 580/600 is needed in the game. The performance differences are significant, comparable to that of the 70-series DC-8s. Several cherished, historic carriers had these "prop-jet" Convairs which soldiered on well into the 90s with commuter carriers (and even 1 major, though NW may have retired them in '89.. my memory is fuzzy).
I have taken the liberty of compiling some proposed specifications for both. I'll cite the current data for the piston drivin Convairliners (240/340/440) already in the game and the data published on Prop-Liners.com as my base, along with runway data from short field airports both the 580 and 600 flew in/out of regularly in scheduled service with Air Chatham in NZ along with Trans Texas Airways/Texas International throughout Arkansas/Louisiana, and last recorded conversion dates for the planes for end of production.
Name: Convair CV-580
Family: Convairliner
Average Speed: 325 mph
Max Seats: 52
Range: 1,863 miles (2,866 max)
Turn Time: 20 min
Average Min. Runway Length: 4,254 ft
Base Price: $16,200,000
Monthly Lease: $180,000
Delivery Starts: January 19th, 1960
Production Ends: End of 1969
Name: Allison 501-D13D
Thrust: 3,800
Weight: 1,750
Fuel Flow: 2,930
Adjusted Price: 16,200,000
Adjusted Lease: 180,000
Adusted Speed: 325
Adjusted Range: 1,863 (2,866 max)
Adjusted Min. Runway Length: 4,254 ft
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Name: Convair CV-600
Family: Convairliner
Average Speed: 309 mph
Max Seats: 48
Range: 1,235 miles (1,900 max)
Turn Time: 20 min
Average Min. Runway Length: 4,098 ft
Base Price: $13,900,000
Monthly Lease: $154,444
Delivery Starts: May 20th, 1965
Production Ends: End of 1968
Name: Rolls Royce Dart RDa10 Mk 542-4
Thrust: 2,750
Weight: 1,560
Fuel Flow: 2,540
Adjusted Price: 13,900,000
Adjusted Lease: 154,444
Adusted Speed: 309
Adjusted Range: 1,235 (1,900 max)
Adjusted Min. Runway Length: 4,098 ft
Additionally, I would like to note/request the production dates for the piston-driven Convairliners be corrected. In the game, currently, all of the piston-driven Convairliners end production at the end of 1965. The last Convair 440 was delivered in June of 1959, last Convair 340 was delivered in September of 1955, and the last Convair 240 was delivered sometime during 1954 (though, to the military, the last civilian 240 was delivered in 1952, I believe). These dates are quite a bit off from 1965.