I've got an idea I am going to try, and I really don't see why it won't work. On my Tams F-16 I am going to tee an airline into the down air line for the gear, with a check valve into the brake line. If I get an air leak in flight and can't extend the gear, I can hit the brakes on the other air system and gear will go down. If all is normal, the down air pressure will not be able to get into the brake system, so all will be as it should. All the full scale aircraft I have flown or been associated with always had an alternate gear extension, and this is so simple I am surprised I never tried it before. Any opinions or ideas? Thanks for the input. Bob