[1][2] The CH 640 was developed from the two-seat type certified AMD Alarus, also called the Zenair CH 2000, by increasing the span of the wings and stabilator, to accommodate the larger engine and increase in gross weight.

The design goals were to produce a simple four-seat aircraft capable of flying cross country flights with full seats.

[2] The CH 640 is a four-seat, low-wing touring aircraft with tricycle landing gear and a single engine in tractor configuration.

Its 31.5 ft (9.6 m) span wing is a cantilever structure and is equipped with flaps.

[1][2] In evaluating the CH 640 AeroNews Network said, "It's a tremendously stable little airplane and a fair amount faster than what you might think.