Hi Deathwish

Thanks for your reply. I found this on eBay at rc-sub-workshop (H.K) to explain how to use the pump to compress air, as you said.

and maybe an electric flight esc, with failsafe on the throttle channel, could open the valve when radio contact was lost...



http://www.youtube.com/watch?v=Oey7q...layer_embedded

Regards
Chris