After serving as a French Air Force captain, Cambronne became the general secretary of the SAAMB factory, in Saint-Cloud, from December 1938 to May 1940 and became the Association des anciens élèves de Sup'Aéro treasurer.
On 27 November 1940 Marcel Bloch gave him a letter, for the Association des anciens élèves de Sup'Aéro:My dear comrades, if the time is difficult, do not despair of the future.
(...) After this war where ships, rolling stock, commercial aircraft have been destroyed, the airline industry will experience an unprecedented boom as it will replace most means of transport.
(...) "No doubt that the government of the French state in a rebuilt Europe will keep our country from aircraft production amounts to our technique and our geographical position in the world.
[4] but after permanent and then intermittent and clandestine communication with Marcel Bloch during his four-year imprisonment, Cambronne is considered "enjuivé" by the Abwehr at the Hotel Majestic and denounced as Gaullist to the Reichsleiter Rosenberg Taskforce.