Flap limit switches

[Wingit]

I am installing GEA24 and GAD27 in a Rv14, the Ray Allen pos sensor goes to GEA 24 and flap support is GAD27, I have read all previous threads and remain uncertain, my question is are the flap limit switches required or best practice, are the limits of of travel defined by configuration. I am using the ms27407-4 flap switch. Where would the limit switches be installed. Thank you.
Dave

[Bavafa]

Originally Posted by Wingit

I am installing GEA24 and GAD27 in a Rv14, the Ray Allen pos sensor goes to GEA 24 and flap support is GAD27, I have read all previous threads and remain uncertain, my question is are the flap limit switches required or best practice, are the limits of of travel defined by configuration. I am using the ms27407-4 flap switch. Where would the limit switches be installed. Thank you.
Dave

By configuration and then the max travel possible by the flap motor itself.

[Carl Froehlich]

Without limit switches, the flap motor will run to the end (or the end of flap travel) then the clutch will slip - the motor still running until you turn it off. A great way to kill the flap motor.

Use the very nice Flap Positioning System from Van’s and end the problem: https://shop.vansaircraft.com/cgi-bi...me&product=fps

Carl

[Bsquared]

I used the Aircraft Extras flap position controller. It is old technology and a bit cumbersome to program but it works well and has a “Reflex” feature that brings the flaps back to the 0 degree position when you select flaps up. You can then toggle the switch one more time to raise the flaps to the -3 degree cruise position. I really like it and use that feature a lot.

[n982sx]

With the Garmin system using the GAD27 no limit switches are needed.

The motor will run to the configured stopping points and stop. You can have the up and down limits be the stopping points and the GAD27 will turn the motor off by itself.

You can program the GAD27 to stop at preselected spots or manually control the flaps to any position. Mine is set for -3°, 0°, 15° and 30°.

In my case, the upper and lower limits are as far as the flap motor will go, so the motor runs for a second after reaching the flap limits then is shut off by the GAD27. No reason to worry about the motor continuing to run.

The Van's system is very nice if you don't have the GAD27 or comparable unit, but the GAD27 makes it redundant. You do need either a position sensor or a flap motor with a position sensor built in.

[KeithB]

+1 for the Garmin GAD 27 - I’m very pleased with it for flap control (as well as many other functions). In addition to the presets, the flap extension can also be speed limited and flaps won’t extend above the preset speed (100 kts in the RV14) with normal activation.

[Wingit]

Thanks for the info. I got a reply from Stein as well, the limit switches are not needed with the Gad27.
Dave

[wjb]

Originally Posted by Wingit

Thanks for the info. I got a reply from Stein as well, the limit switches are not needed with the Gad27.
Dave

ONLY not needed if you have a a flap positioning potentiometer connected to the GEA24 engine monitor (and have the system correctly configured for this). I found that I have a flakey connection under the panel that makes the flap positioning pot reading unreliable. I disabled the pot and went with manual flaps.

My flap up switch stays "on" when switched up (down in momentary) .. and if I don't turn off the switch, the motor will run forever once the flaps are up -- like Carl sez.

However, I was prescient enough to run the limit switch wiring on initial install, and now I have a wired up limit switch that stops the motor once the flaps are up.

Now, I'm totally used to the manual flaps and likely keep it this way (tho I will fix the connection next time I get into that area of the avionics ... kinda a pita to get at right now). The up switch on the GAD27 does the job perfectly.

[Champ]

Up limit switch with diode for reversing. Works great. Momentary contact on stick for down so I count 1-1000 etc then look outside & check mark on flap to confirm degrees down. Up is maintained contact on stick & limit switch to stop it. Recenter switch when I remember.

[georgedouglas]

Originally Posted by Carl Froehlich

Without limit switches, the flap motor will run to the end (or the end of flap travel) then the clutch will slip - the motor still running until you turn it off. A great way to kill the flap motor.

Use the very nice Flap Positioning System from Van’s and end the problem: https://shop.vansaircraft.com/cgi-bi...me&product=fps

Carl

I just installed the showplanes flap system and am pleased with it so far. I installed it more for a safety measure than flap positioning in the pattern. My previous aircraft had the flap switch that once you moved it to retract it brought the flaps up automatically. This is one less thing to worry about when making a go around. With the system I replaced you had to hold the switch up until the flaps retracted, which tied up one hand that might be needed for something else in a serious go around.
george