The Praga E.114, first flown in 1934 and designed by Jaroslav Šlechta, was a high wing, cantilever monoplane seating two in a side-by-side cabin.

The wing had a constant chord centre section with taper on the trailing edge outboard and rounded tips.

[1][2] Its fuselage was a pine framed, plywood covered hexagonal box, with the straight edged fin an integral part.

[1][2] Early in the design process the E.114 had been envisaged as an open cockpit aircraft but by the time of construction there was an enclosed cabin.

The undercarriage, which was also used as a first step into the cabin, was of the divided type with faired legs hinged on the lower fuselage, assisted by struts from the centre line to the wheels.

The wheels contained rubber shock absorbers and were optionally spatted[1][2] Early aircraft were powered by a 29 kW (36 hp) Aeronca E-113 air-cooled, boxer two-cylinder engine mounted in the extreme nose with its cylinders exposed.

The ailerons were balanced, improving the stall characteristics; the vertical surfaces were increased in area and given a more angular profile with a non-balanced rudder.

The E.115 also had a revised undercarriage, with single, streamlined steel struts hinged to the lower fuselage braced by rods to the centre section.

The wing remained wooden but a steel framed, fabric covered fuselage was used and the fin and elevator were similarly constructed.

[2] The first Air Baby prototype flew for the first time in September 1934 and appeared at the Czech National Flying Club Competition.

The two E.114 pilots, Fuksa and Polma, took the first two places ahead of competitors, equipped with aircraft with more powerful engines.

[citation needed] Before the war some Czech built E.114s were exported to other European countries including Italy and Romania.

The Praga B engines manufactured in the UK by Jowett Cars Ltd proved unreliable and at least five were replaced by the much heavier 30 kW (40 hp) Aeronca JAP J-99 flat twin.

[6][8] A Hillson Praga won the Manx Air Derby, flying three circuits of the Isle of Man on 1 June 1936 at 144 km/h (89.5 mph).