AP1 AV : 1958 - Env. BY AIR MAIL '1st session Schuman's presidency'

N°AP1 AV : envelope "BY AIR MAIL" "1st Day of the 1st European Parliamentary Assembly session 13-14.05.1958"
Postage 1 value Stamp 20F "Europa 1957"
Cancellation Strasbourg 13.5.1958 (type RP1)
to be forwarded on the inaugural flight «Austrian Airlines Paris - Wien»


Notice: The envelopes have travelled on board of the "inaugural flight Austrian Airlines Paris-Wien" on May 1958, but no one includes an arrival postmark.
Indeed, 250 letters had been prepared for this flight and in that case, the PostOffice requires the letters in number to be packaged in the same parcel sent by mail. Considering that the address of an arrival postmark is not an obligation, the parcel had been treated such as one letter without being never opened.