My Gas plane parachute project
Hi.
After witnessing nearly a crash a day at my local field and noticing a reference to a parachute in another thread, I am wondering if there is a parachute recovery system available? After researching the recovery system for full size planes http://www.brsparachutes.com/default.aspx , it looks like it could be made with a small toy rocket and a parachute.
I've seen a video X1 rocket video with B-29 in which a X1 plane is released from a B29 and then a rocket is ignited and it shoots up into the sky. So there is a way to make to the rocket part work.
I've made a few parachutes over the years, from the smallest of half a meter diameter to one of almost 3m and I liked to throw a bottle of water and watch how it deploys and slowly descend. Now, after days of working I've managed to make my biggest chute of all and an functional release system in a gas airplane.
The chute is made from polyethylene the one that we cover the furniture when painting the house, but not the softest, it is very light material a sort of nylon that can be very hard glued. I've made it of 5m diameter so that an object (the plane in this case) of about 7-8kg will have no more than 2,5 - 3m/s descent rate. It was quite difficult to make it in a two bedroom apartment but not impossible. When I pack it its quite small.
The plane is Great Planes 27% CAP 232. The chute is mounted in the cockpit. Long story short: two servos pull 4 pins, unlocking the reinforced canopy. A spring pushes it up, the air does the rest, blows the canopy of the plane and inflates the chute. I've mounted the lines under the chute in an similar order as on the real chutes like in S shape and a soft paper on top not to get in touch with the chute.
Of course I didn't attached the chute directly on the airframe, I mounted 2 bolts in the landing gear wood block and an aluminium piece from them to the firewall which are the strongest places on the plane. From here two strong elastic cords (from an fitness extensor) go trough the fuselage to the cockpit and another two non elastic cords of different lengths with springs are the second and third impact absorbers. Also I've mounted a slider ring over the 32 lines like on real chutes so that it deploys gradually also reducing the shock. The shock cords go trough two O ring metal shapes that are attached to the internal structure so that if the chute is above the plane the stress will not go on the cockpit panel itself. The entire weight of it is about 600g from which the chute is 450g.
I've been dreaming at this system for many years but it seamed hard to realise. It was more like a challenge if I can do such a system. The system has been tested on the ground and it works, the canopy is blown out, and the chute is trown out and starts the inflation but because of the ground it can't fully inflate. I realise that there are situations in which a chute can save a plane, or not and I don't know if the structure of the plane would resist with all the measures taken but I know that if it can be used in one situation of lets say wing break or elevator break at some altitude the chute will make the difference between ''the plane survived with minimum or some damage'' and ''the plane is completely destroyed with all it's insides''.
This plane floats very well, it's been like a testing platform for me over the years, and I don't plan on making it lighter to perform 3D so for my sport flying the extra weight has little efect. My post is an answer to the person who started this thread and to those that, like me decided that for them it's worth making this project and carrying the extra weight. I've read all the threads about this and I'm aware about the scepticism. I'm not asking here anybody if it can be done or if it's worth doing it. I'm presenting it all done and working, I've made my decision if it's worth or not for me when I started building it. Maybe if I also had 10 gas planes I wouldn't bother on anything else than flying them. I'm addressing and want to inspire those that are interested. Thank you!
Last edited by jak_kkaall; 01-15-2015 at 03:15 AM.