Squat Switch Ideas

[BruceMe]

Originally Posted by dbuds2

I've been studying the new SkyView transponder installation and see the option for a Squat Switch. Has anyone used a Squat Switch to turn the TPX from ground to airborne operation?

I was thinking some kind of switch on the tail wheel. When on the ground and flexed up it would be open circuit and close as soon as off the ground and unloaded.

Check the Tx mfg's installation documentation. I suspect since the Mode-S needs a NEMA (GPS) input for position data... it may have an internal "I have groundspeed" enable/disable capability. If I built one, I'd put it in there.

[KRviator]

Originally Posted by BruceMe

What about S&L unaccellerated flight? Mercury goes center... Mode-S turns off

Hence the airspeed switch. For Mode S to be deactivated, would require Airspeed <40KIAS (or whatever you set it at) and a nose high attitude. The only other time I can think of that occuring would be during a hammerhead.

[David Paule]

Originally Posted by dbuds2

I was thinking some kind of switch on the tail wheel. When on the ground and flexed up it would be open circuit and close as soon as off the ground and unloaded.

On any sort of rough ground, during landing or take-off, there's probably enough bouncing at the tailwheel to open and close the switch a few times. It would, at minimum, need a dampening or delay circuit or some sort to allow for that.

[LuisR]

This may not affect MOST of us but...

How about the traffic anti collision that ground uses during low visibility that works with the transponders while on the ground. Probably a system for MAJOR airports. I can't think of the name of this system right now. You won't be able to participate without an active transponder on the ground.

correct me if I'm wrong....Just my thoughts...

[jsharkey]

My GTX 327 goes from standby on the ground to Mode C automatically on take off. It uses increase in altitude to trigger the switch.

Jim Sharkey
RV-6

[ronschreck]

Originally Posted by KRviator

Would an airspeed switch wired in series with a mercury tilt switch work for you? The airspeed switch would ensure it was deactivated above a certain airspeed, while the tilt switch would require a nose-high attitude in conjunction with no-airspeed to close the circuit...

So your transponder would turn off every time you did a hammerhead turn?

[KRviator]

If I was doing a hammerhead turn in my -9A I've got bigger problems than worrying about what my transponder is doing.

But, yes, using an airspeed & tilt switch in series probably would put the transponder to standby during such a manevoure.

[sailvi767]

Originally Posted by Manny

This may not affect MOST of us but...

How about the traffic anti collision that ground uses during low visibility that works with the transponders while on the ground. Probably a system for MAJOR airports. I can't think of the name of this system right now. You won't be able to participate without an active transponder on the ground.

correct me if I'm wrong....Just my thoughts...

Most major airports require the transponder to be on from pushback. I suspect however that very few RV's will operate out of airports with ground radar. The system is very expensive and is not likely to be in place at any airports other then the largest. A simple call to ground to tell them the transponder will not be on for taxi would be fine at those airports as long as the vis was not below a 1/2 mile or so. Again this would be rare I hope for a RV.

George

[bignose]

Originally Posted by sailvi767

Most major airports require the transponder to be on from pushback. I suspect however that very few RV's will operate out of airports with ground radar. The system is very expensive and is not likely to be in place at any airports other then the largest. A simple call to ground to tell them the transponder will not be on for taxi would be fine at those airports as long as the vis was not below a 1/2 mile or so. Again this would be rare I hope for a RV.

George

Dynon's Skyview Mode S Transponder allready has a "Ground" Mode.

[chinch]

We have heard of simple strain gauges on undercarriage to successfully and reliably indicate airborne status for tracking systems - does not seem to be a reason why this would not be equally useful for txpnder.