The Z-37 Cmelak (Bumble Bea) was designed and built by LET Narodni Podnik, the LET National Corporation which evolved from a branch of the Skoda series of companies.

The Let Z-37 Cmelak (Bumblebee) was an agricultural aircraft designed and built in Czechoslovakia, work commencing in 1961 and the prototype the XZ-37 first flew on 29 March 1963.

Development Technology Aero (DTA) later known as Delta Trikes Aviation) was founded in France in 1990 by Jean-Michel Dizier to produce a range of trikes and machines were developed to meet aerial work requirements, including agriculture, territorial tracking and pipeline work.