Switzerland Registered Flight stamps year 1988 50 years Pro Aero Flight Special

Switzerland Registered Flight stamps year 1988 50 years Pro Aero Flight Special FDC covers ?? Switzerland 1988 Pro Aero Special Flight Year of Issue: 1988 Event Commemorated: The 50th Anniversary (1938-1988) of the Pro Aero Foundation. Pro Aero Foundation: This Swiss foundation is dedicated to promoting aviation and encouraging young people in flying, gliding, and other aerial sports. They have a long history of issuing special postal items to raise funds. The Item: The item you are referencing is a Special Flight Cover (SFC), often referred to as a “Registered Flight” cover because it was sent as registered mail on a commemorative flight. Features: It is an envelope (cover) that bears the necessary postage (regular and/or airmail stamps) and is marked with special commemorative cancellations (postmarks) and a registration label to certify it flew on the designated special route. Flight Details: The cover often includes cachets (pictures printed on the envelope) and cancellations specific to the flight route, such as the one mentioned in search results: Genève – Zürich or Samedan – Agno – Genève aeroport. Philatelic Significance: These are highly sought after by collectors of Swiss stamps and airmail (aero-philately). They document specific events in Swiss aviation history.