If you have an interest in Polish aircraft and or the "SP" Polish civil aviation register then you may want to join and contribute to my Facebook group, see below

Polish Civil Aviation - Polskie Lotnictwo Cywilne

https://www.facebook.com/groups/892627295471562

 

Historic to Modern - S-13 Ambulance SP-BIB(1) registered in September 1957, here is the original register entry - SP-BIB has been re-used twice since then - BIB(2) Sekpol balloon from 1998 to 2008 and BIB(3) Lindstrand balloon from 2019.  

Anything "SP-" registered can be discussed !

 

The group is for SP registered aircraft/gliders/helicopters/ultralights/balloons/gyrocopters after 1945 till today.