SNECMA began work on pulse jets in1943, when the first studies were carried out by an engineer named Bertin. They lead in 1948 to a first stable operation and in March 1950 the definite version of the "Escopette".
The Escopette 3340 develops a thrust of 10 kgf with a specific fuel consumption of 1.8 kg / kgf / h. (At the time, turbojets consumption is about 1.3 kg / kgf / h.) The total length of 2800 mm and a nozzle diameter of 157 mm.
For flight testing, a Kestrel flying testbed was made available to SNECMA. The SA.104 kestrel glider was transformed by SEVIMIA under the direction of engineer Jarlaud. Each group of thrusters is fixed to the wing at the front by a mast secured to the rail and mounted on a bracket mounts, and secondly by a false spar. Before the mast is a passage to fuel and ignition lines.
First flight towed occurred at the end of November 1950 at the SNECMA field in Melun-Villaroche, piloted by Chief Pilot Leon Gouel. The first autonomous flight was conducted on December 19, 1950, and a camera is always equipped for the first four tests.
The Kestrel takes off with this 40 kgf thrust for a total take-off weight of 320 kg. Many flights are made until the end of 1951 in this configuration. At that time, an Emouchet SA. No. 224 104 glider has two groups of three pulsos (60 kgp total thrust).