Juha Heikkinen writes:
After the 2006 Bear Cup event in Finland we had an interesting 'seminar' with Victor Tchop. The seminar was arranged by Jari Valo who nowadays flies using Tchop models.
Victor told us how he got into flying and many stories about the old days, flying in Soviet Union and his attitude and thinking about the F1A. I was really surprised as he told us using bunt launch already in 1975!!! Of course the models were wooden and they didn't withstand the launches properly. He spoke only in Russian (I don't understand a word), but Jari and the Estonian guys translated the stuff into English so there might be something that we missed. Victor didn't say much about bunt development, but I had the feeling that the technique was tested in his local field but couldn't be used properly before 1989.
There were also some similar development in Finland around 1984-86, as Petri Sahi (3rd in Argentina 89) experimented with bunt in his gliders. Petri used gliders sporting tubular carbon fibre main spar. Maybe the clockwork timers were not accurate enough or the bunt systems (copied from F1C models) not suitable for the models as I have heard that the launches were not reliable enough.