Automatic Landing Gear and Flaps

[ForrestGump]

Folks,

This is by far one of the best forums I've landed in. I got shocked when I saw the usefull stuff you guys are discussing about. Congratulations.

Maybe some of you may help me with one idea I'm playing with ... The thing is to build an airspeed sensor that one could set a landing and take-off airspeed so that when taking off airspeed is reached the device (PIC based I guess) would retract the landing gear, and when landing airspeed is reached it deploys landing gear and flaps.

I think I saw something similar in MAN or RCME sometime ago but the good thing is the DIY.

My initial idea is to use a differential pressure sensor (motorola?) and a PIC. Any thoughts?

Thanks in advance
Antonio
PS.- Apologies for my awful English (not very used over here in Spain) :D

[Comatose]

Its quite possible. The only problem I could see is if you lost airspeed for some other reason, stall or 3d or whatever, then the gear would also come down. It might be a good idea to couple it to a ground proximity sensor as well, like one of the Sharp IR distance sensors, or an IR proximity sensor.

[ForrestGump]

I had not think on that because I intended to use it on a scale airplane (not 3D).

Trying to keep it simple and cheap. Wouldn't be enough to monitor also the thorttle stick to check if it is close to idle position to deploy the flaps and landing gear?

So if one is doing aerobatics ( Torque roll :p ) the gear will not come out.

Antonio.

[zagisrule!]

I would check input radio signal and airspeed, but that could cause problems as far as the gear deploying. What if you are coming in a little hot and your gear does not deploy? ;)

I have no idea what the range is on the IR sensors, but I imagine that it can not be more than a foot or two...but I could be wrong.

I bet that the airpressure sensor will be hard to calibrate like you want as well.

There must be a reliable and simple way...do you not have a fifth channel?





-Matt

[ForrestGump]

Yes I have a fifth channel, but I also have left hand and this does not avoid me from using a gyro in me helicopters :p

The idea is that when I'm landing and want to switch ch 5 . I have to briefly release the stick , switch ch5 on and get the stick again and this makes me very nervous mainly with non very stable aircrafts.

I though this could be a good solution but it seems I may be wrong. Since it can become a too sophisticated devidce for me :o

Thanks to every body that expressed their opinions. They were very appreciated.

Antonio.

[zagisrule!]

What about adding a new switch to your transmitter in a more convenient location? That is much simpler than trying to rig an airspeed sensor...

What radio are you using?



-Matt

[ForrestGump]

I Think it can not be done with my actual radio. I'm using Futaba FF8 Super but to be honest the Futaba 9ZAP WCII is coming (hopefully) in a couple of days.

I guess it will be different with the 9ZAP cause I've been told one can selact any switch for any function (with FF8 you cannot).

Thanks.
Antonio

[AndyKunz]

I believe that on a full-scale Italian private plane the gear comes down ONLY when the flaps are down AND airspeed drops to a certain point. Are you using flaps? That would take out the inadvertant gear drop during maneuvers.

Andy

[Comatose]

The IR sensors come in up to about 5 foot range. It's not much. Sonar would get you farther, but at speed it might be flakier.