"squat switch" output

henryhallam

Lancair 360 with SV-D1000 and SV-D700
Joined
Oct 18, 2016
Messages
18
Location
KEMT
My retractable Lancair doesn't have a squat switch to prevent inadvertent retraction on the ground. I haven't done so yet, but they say prevention is better than cure...

In lieu of an actual squat switch detecting weight on wheels or a separate pressure switch plumbed to the pitot system, is it possible to get an output signal from my SkyView that goes high (or low) when airspeed is above some threshold? I could then use a MOSFET and/or relay to interrupt the retract control circuit.
 

preid

Member
Joined
Jan 22, 2010
Messages
753
Location
SoCal
go to install manual page 7-70 & 7-71
The simplest method to monitor landing gear state is to use a contact as there are only two states to monitor and it is mechanically and electrically easiest to install. To enable audio alerts related to landing gear status, the contact used for monitoring the status of landing gear must be named GEAR:
SETUP MENU > EMS SETUP > SENSOR INPUT MAPPING > C37 Pxx >
> FUNCTION: CONTACT
> SENSOR: CONTACT
> NAME: GEAR
To configure the GEAR contact alert for retractable landing gear:
• Install the GEAR contact that when the landing gear is up, the state of the contact is UP and when the landing gear is down, the state of the contact is DOWN.
• SETUP MENU > AIRCRAFT INFORMATION:
> LANDING GEAR TYPE: RETRACT
> LANDING GEAR CHECK SPEED: (set as appropriate for your plane)
> LANDING GEAR OVERSPEED: (set as appropriate for your plane)

Granted this is a monitor/reminder not a way to stop you or anyone from hitting a switch by mistake.
but you do get a “Check gear” and “gear overspeed” audio alerts for retractable gear aircraft that are tied to both landing gear status and airspeeds.
 
Last edited:

henryhallam

Lancair 360 with SV-D1000 and SV-D700
Joined
Oct 18, 2016
Messages
18
Location
KEMT
Thanks but that's the opposite of what I need :) I do already have gear status monitored by the Dynon. I guess I'll add a dedicated pressure switch, it would just be nice to avoid adding additional fittings to the pitot system.
 
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