Mono Aircraft was founded in 1927 and their first design was the Monoprep high-wing sporting two-seat open cockpit monoplane. Eight Monopreps were built.
The improved Monoprep 218 followed the initial model in 1929, with a 3 ft (1 metre) shorter wingspan giving increased speed. 84 Monoprep 218s were built by 1930. One long-nosed aircraft was used to test one of the two Lambert H-106 engines during 1930.[1]
The sole surviving example of the Monoprep 218 NC179K was publicly displayed in airworthy condition in the Airpower Museum at Ottumwa Iowa.[2] It has now changed into private hands and is under restoration to fly again.