Studies began in 1983 of a 40-seat pressurised development of the L-410 feederliner powered by two newly developed Walter M-602 turboprop engines driving five-bladed 'quiet' propellers. Prototype construction of this L-610 began early in 1988 and the first of three flying prototypes was rolled out in November. The first flight took place on 28 December 1988, and the type was exhibited at the Paris air show in June 1989. The first of 600 aircraft for Aeroflot was shown at the Paris air show in June 1991, and others are on order for CSA. Current activities centre around the completion of the flight test programme and achieving certification. To improve sales prospects to the West, one of the prototypes (re-designated L-610G) is being re-engined with 1305kW General Electric CT7-9Ds, and was due to fly before the end of 1991, with certification and first deliveries targetted for the end of 1992. Let has also announced plans to stretch the L-610 into a 50-55 seater, probably using GE CT7 or PW100 engines.