01/15/2019. Remarks by Walter van Tilborg: "The prototype of the two-seat SP-2 Gaz'aile first flew during November 2005 and the aircraft was a design of Serge Pennec who also marketed plans for amateur construction. It followed the earlier Pennec-Lucas PL-02 Dieselis and was like the latter designed for the use of smaller automotive diesel engines. The type name Gaz'aile is a combination of the French words gazelle and aile (wing).

Gaz'aile 1 was the name for the original prototype Dieselis (registered F-PTDI) after it had received modifications and a more powerful Opel Astra diesel engine (the aircraft originally had a 68 hp Opel Corsa (Isuzu) 1,500 cc diesel engine.

The SP-2 Gaz'aile 2 is a much improved Dieselis derivative, the prototype (F-PGPS) was first flown during 2006 and used an 106 hp PSA (Peugeot-Citroen) 1,400 cc AX-106 diesel engine. This aircraft formed the basis for the homebuilt variant (available in plans form) and by late 2018 at least over 20 had already been completed and flown (over 18 in France). The SP-2 used a tricycle landing gear as standard, although at least one aircraft in France had been built with a conventional tail wheel landing gear. Most examples were fitted with small 80-100 hp diesel engines, but several builders opted for non-diesel units of similar power. The Gaz`sile has been observed with several types and sizes of winglets.

Gaz'aile 2 ULM: This ULM version (France) was first flown in 2010 and the first example was built by Jackie Amiel. To qualify as ULM the Gaz'aile used lighter engines and an increased wingspan. was to 26.902ft. This variant was built without registration or in the F-J… series.

ABC-FLY22 is a ULM variant built in Tunisia and a prototype first flown around February 2017."