jdsterli

Hello everyone! Im in the process of purchasing a H9 Taylorcraft w/ zdz 40. I am trying to build a UAV and I want to have some kind of recovery system. I was wondering if anyone knew of a servo-activated parachute recovery system, or some other way to recover a plane if it is out of RC control. Thanks for your help!

mulligan

It's been done, and I've seen a thread or two here on RCU- do a search.

Basically, if you have a PCM radio, you can have a servo deploy a parachute in failsafe mode (in addition to killing throttle). Just make sure the parachute and connections are strong!

- George

Dave03B

How do you deploy the chute though?

Shortman

My Feedback: (21)

How would you put the parachute on though? If you put it on the tail it would nose in but would it function on the wing when flying forward?

Dave03B

Couldn't a modified Model rocket chute (bigger) be folded under the canopy and the canopy pop up and release the chute.
Trouble is how to pop the canopy?

Shortman

My Feedback: (21)

depends on the plane, with the taylor craft the wing would have to pop off to with the canopy hehehe

Edwin

My Feedback: (2)

A system like this exists for full scale high wing planes. Its in a compartment fastened to the CG on top of the wing. The real one is actuated with a rocket so the chute will clear the tail section. Lands on it gear. Saw it on Discovery a while back.
Edwin

dunk-RCU

Do a google.com search for: Airplane parachute recovery you will get over 4000 hits including a discussion on attachment point locations and the CG.

Dave03B

Now, there is no problem in getting the right size Shutes because you just buy a Large model rocket recovery shute. However the problem still it deploying the shute.
Perhaps a servo which is set on PCM as a failsafe locks the (sprung) canopy down. The shute is under the canopy and once the canopy is blown off by airspeed after failsafe servo releases it the shute is pulled out by airspeed and then floats your model safely back down.

How about it?

Give your ideas!

aircowboy

My Feedback: (10)

build a compartment in the top of your wing for the chute. Use a servo to open the chute. To make sure the chute clears the tail, line the bottom with a piece of balsa ply with a spring under it. When the hatch opens, the spring will push the floor of the compartment out(balsa ply piece) and deploy your chute. The balsa ply piece will be lost, but is a small price to pay for your save plane. I am not sure how you would activate your servo if you lose r/c, but I also dont have a computer radio and dont know how failsafe mode works. My only concern would be having the chute deploy accidently. It would definitely catch you by surprise and your plane may not land where you want it to(not a concern if you lose r/c).

Dave03B

If you have a computer radio you're ok. You can set the PCM failsafe so that in the event of the rx loosing signal from the tx, the failsafe (cut throttle, pop the chute) cuts in.
If you were in an uncontrollable situation, you cut cut the throttle your self, then just turn the tx off.

I have been reading about a Ripmax Hal autopilot that is linked up to your alieron and elevator and and detects whether of not you input the correct, opposite control, (if you were inverted) if you did not input the opposite control to regain level flight, the Hal system does it for you. The level of input HAL has over the aircraft can be adjusted in-flight.

I'll have to think about the servo mech for the chute release!

Dave03B

can't find ParaCat Recovery System. Damn would have been such an easy way out.
Oh well have to make one.

FreakyFlier

My Feedback: (1)

You can convert the top wing "sunroof" to a parachute compartment. Just cover the area with balsa and use a spring latch connected to a servo.
I am a little confused though. It seems we try to make things too complicated, myself included. If a plane were to be out of control you basically have to watch it ride in. The draw back to your system would be a midair deployment at a time other than needed. If you take a 2 or 3 second hit, do you really want a chute to deploy? I would rather fight it and hopefully outlast the hit. Most of our flights are below 150 feet, Would a chute really have time to work?

Erich_F

Hey all,

I think we're missing an important distinction here. If this is for a UAV project, that means autonomous operation, NOT radio control, at least not entirely by radio control. Using PCM failsafe to release a 'chute will cause chute deployment as soon as the radio signal is turned off and the aircraft attempts autonomous flight. If this is for initial project research, where the aircraft is entirely under radio control, then I could understand using PCM failsafe and/or Aux channel to automatically or manually deploy the chute. However, the spirit of a UAV is autonomous operation.

In that case, you would need sensors that detect an out of control or off course situation. GPS and gyros could fit that bill. Airspeed sensors could also detect stall/overspeed situation.

So, the big question is...is this project a UAV or RPV?

Erich