Garmin?s new GAD 27 interface module pairs with G3X? Touch to streamline (11/18/15)

[Tnikkel5]

Is the flap switch inputs low power also like the lights?

[g3xpert]

Originally Posted by Tnikkel5

Is the flap switch inputs low power also like the lights?

Hello Tnikkel5,

Yes, all pilot switch inputs to the GAD 27 (flaps, trim, and lighting) are low-power logic-level inputs.

- Matt

[togaflyer]

In order to have the discrete input display items like landing lights on, pitot on, boost pump, etc; do you need to change those switches out from a single pole single throw, to a double pole double throw. I was told because its a ground that activates the discrete inputs, I need different switches. Or can it be wired in with the typical single pole single throw I planned to use.

[g3xpert]

Originally Posted by togaflyer

In order to have the discrete input display items like landing lights on, pitot on, boost pump, etc; do you need to change those switches out from a single pole single throw, to a double pole double throw. I was told because its a ground that activates the discrete inputs, I need different switches. Or can it be wired in with the typical single pole single throw I planned to use.

Hello togaflyer,

A G3X Touch system with a GEA 24 and a GAD 27 has support for 13 user configurable input discretes.

The 4 input discretes on the GEA 24 may be configured for either active high or active low. The GAD 27 supports 7 active low and 2 active high input discretes (see page 24-11 of the Rev. V G3X Installation Manual).

You may, in some cases, need a double pole switch to isolate the activation of the input discrete, but not often.

You would normally connect a powered device like a boost pump to an active high input discrete which would transition to active high when power is applied to the boost pump (and the input discrete). This would allow you to display a message on the PFD any time the boost pump is turned on and would not require a double pole switch.

As discussed in a previous post, the light switches in an aircraft with a GAD 27 will no longer directly switch the power to the lights, so a simple low power SPST logic switch may be used if desired. If you also wish to display an annunciation on the PFD when one of these lights is on, you could also connect this switch to one of the user configurable active low input discretes on the GAD 27.

If you have any specific installation questions, please contact us by email or phone as shown below.

Thanks,
Steve

[luv2flypilot]

I was hoping to get some info on how the GAD 27 works for flap control. It appears you can set it up for up to 8 positions so I should be able to set say 10, 20, 35 degrees? I typically park with my flaps down for ease of getting in and out of the plane and have had a problem in the past with the flaps at full down position causing damaging if pressure is put on the wing where the flaps fold under, therefore I typically park with my flaps at around 35 degrees. I also have found that I really do not need to use more than 35 degrees on any landings as the RV-7 flaps work very well.

I am also wondering if the flaps up switch can be a locking up position switch so that it allows the flaps to go back to the 0 degree position then turn off the flap motor without having to hold the switch in the momentary up position when practicing touch and go's. Maybe this is something in programming that you can set for a single momentary up input that times out the flap motor all the way back to 0 degrees without holding the switch in the up position rather than using a non-momentary locking up position switch that times out the flap motor?

Possibly it works like the Flap Positioning system that Aircraft Extras has available?

It allows you to program as many flap stop positions and put them where you desire. For Touch-N-Go Operation: As you come in for a landing with full flaps, you land and then prepare for take-off again while rolling. If you hold in the "Flap Up Button" in for longer than 1 second, this commands the flap positioning system to start moving to the o flap take-off position. While the flaps are retracting, go to full throttle, punch in the carb. heat, and take-off.

[g3xpert]

Originally Posted by luv2flypilot

I was hoping to get some info on how the GAD 27 works for flap control. It appears you can set it up for up to 8 positions so I should be able to set say 10, 20, 35 degrees? I typically park with my flaps down for ease of getting in and out of the plane and have had a problem in the past with the flaps at full down position causing damaging if pressure is put on the wing where the flaps fold under, therefore I typically park with my flaps at around 35 degrees. I also have found that I really do not need to use more than 35 degrees on any landings as the RV-7 flaps work very well.

I am also wondering if the flaps up switch can be a locking up position switch so that it allows the flaps to go back to the 0 degree position then turn off the flap motor without having to hold the switch in the momentary up position when practicing touch and go's. Maybe this is something in programming that you can set for a single momentary up input that times out the flap motor all the way back to 0 degrees without holding the switch in the up position rather than using a non-momentary locking up position switch that times out the flap motor?

Hello Bryon,

Yes, you may certainly setup your GAD 27 based flap control system to have 0, 10, 20, and 35 degs of flaps for your RV-7.

You also have quite a bit of flexibility in the flap control switch including the one you suggest which is momentary on when pressed down and "non-momentary locking" in the up position. We actually have one of those switches in our RV-7A. You bump it down to extend the flaps to the next position, then on a touch-and-go you can just flip it up and it will fully retract the flaps. Even with this switch design, you can pseudo bump it to retract flaps to any intermediate flap position. For example, for your 4 flap positions, if you want to retract from full flaps (35 degs) to 10 degs, you can flip the switch up and back to center twice and the GAD 27 will take the flaps up to 10 degs.

Just a reminder that you can also bump the momentary contact down switch multiple times. For example, lets say your flaps are full retracted and you want to skip the 10 deg position and extend directly to the 20 deg position. Just bump the switch down twice and watch it go. The cyan selected trim position pointer on the trim position gauge on the PFD will immediately move to show that you selected the 20 deg position.

Thanks,
Steve

[luv2flypilot]

Originally Posted by g3xpert

Hello Bryon,

Yes, you may certainly setup your GAD 27 based flap control system to have 0, 10, 20, and 35 degs of flaps for your RV-7.

You also have quite a bit of flexibility in the flap control switch including the one you suggest which is momentary on when pressed down and "non-momentary locking" in the up position. We actually have one of those switches in our RV-7A. You bump it down to extend the flaps to the next position, then on a touch-and-go you can just flip it up and it will fully retract the flaps. Even with this switch design, you can pseudo bump it to retract flaps to any intermediate flap position. For example, for your 4 flap positions, if you want to retract from full flaps (35 degs) to 10 degs, you can flip the switch up and back to center twice and the GAD 27 will take the flaps up to 10 degs.

Just a reminder that you can also bump the momentary contact down switch multiple times. For example, lets say your flaps are full retracted and you want to skip the 10 deg position and extend directly to the 20 deg position. Just bump the switch down twice and watch it go. The cyan selected trim position pointer on the trim position gauge on the PFD will immediately move to show that you selected the 20 deg position.

Thanks,
Steve

Steve, It does not appear there is a flaps maximum run time setting within the G3X Touch settings? I have a flaps switch that locks in the up position so I can just push it up for full flaps retract during a touch and go, however if I forget to push it back to the normal position my flaps motor will continue running. Am I missing something within the set up?

[g3xpert]

Originally Posted by luv2flypilot

Steve, It does not appear there is a flaps maximum run time setting within the G3X Touch settings? I have a flaps switch that locks in the up position so I can just push it up for full flaps retract during a touch and go, however if I forget to push it back to the normal position my flaps motor will continue running. Am I missing something within the set up?

Hello Bryon,

Yes, we have a flap switch like that on our RV-7A.

You don't have to configure a maximum run time on the flap motor because the system automatically monitors the flap retraction and stops the flap motor when either the zero position is reached or when the flap movement has dropped below a minimum velocity for about 3 secs.

If you have a pre-programmed reflex position (like common on RV-10s), the system still stops at zero on the "held" retraction so you don't end up reflexed when you didn't mean to. If you want to go to the reflex position after a full flap retraction to zero, just flip the switch down, then back up.

Let us know if you still have questions.

Thanks,
Steve

[tgmillso]

I had a question I wanted to confirm regarding the use of "Keep alive" power during the startup sequence. I presume that this gets wired into the secondary power input pin on the G3X GDU460 and the GEA 24? Also, would you have these devices on the main bus, or would you have them on the avionics bus that you kept off during start, so that they are pulling power instead through their secondary power input wire that is "filtered" through the GDA 27, keeping only the GAD 27 on the main bus? If there's a page in the manual that points me to this, feel free to throw it in my direction, however I was unable to find anything that related to this.
Regards,
Tom.

[tgmillso]

If I have an alternator failure and shed pretty much all loads except my G5 and Aera 660 (i.e. I turn off my G3X) but keep power to the GAD 27, am I still able to operate the flap and more the trim if they are wired through the GAD 27?
Thanks.
Tom.