SNCASO SO.4000
1951 French experimental bomber aircraft
The SNCASO SO.4000 was an experimental French twin-engine bomber of the 1950s. It was the first French jet bomber developed, but it never entered operational service.
The SO.4000 was developed because the French Air Force needed a jet bomber, which produced a specification calling for one after the end of Second World War. The SNCASO's SO.4000 received a development contract to produce a pair of mockups and a full-scale prototype. The single full-scale aircraft, which performed its first and only test flight on 15 March 1951, would never enter mass production. Even prior to this flight, the design had been made obsolete by rapid advances in the field of aviation and was overweight and underpowered. Shortly after its only flight, during which it had been damaged during the landing, it was decided to abandon development. However, the SO.4000 would form the basis of the far more successful SO.4050 Vautour.
Development
France's aviation industry was in dire straits, having been damaged more heavily than any other Allied nation as a consequence of the Second World War. Regardless, the French needed to revive the nation's aviation industry, and to use the latest advances for a new generation of competitive locally built aircraft.
The public source identifies “SNCASO SO.4000” as 1951 French experimental bomber aircraft. This brief keeps that definition visible, then builds a research path around SNCASO, French and experimental.
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Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Mar 29, 2026. The linked authority identifier is Q3943785. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1951.
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This entry incorporates text from “SNCASO SO.4000” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.