FRANCE AVIATION - AIR FRANCE - VOYAGE D' ETUDE * JULY 9 - 11 - Lot 141

FRANCE AVIATION - AIR FRANCE - VOYAGE D' ETUDE * JULY 9 - 11 1946. RARE lettre recommandée enveloppe AIR FRANCE, affranchissement 40 F Sagittaire (av 16) au départ de PARIS-AVIATION, C.A.D. 9 juillet avec étiquette recommandation Paris-Aviation + special flight circular stamp - Letter for LEOPOLDVILLE - BELGIAN CONGO. on verso arrival Léopoldville July 12. * Trip made on four-engine LANGUEDOC aircraft. Take-off from Le Bourget to complete endurance tests on the aircraft, whose final destination was the Congo. Trip to test infrastructure at stopovers, timetabling and liaison at stopovers. Above all, the aim was to confirm the qualities of this new four-engined aircraft through flights in extreme conditions: good engine performance on take-off, flights with the engine stopped, autopilot testing, flights in a high-temperature region, severe and sudden atmospheric disturbances that could lead to engine failure, etc...