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New aircraft all "lectricary" so I think I would like to have a back up air speed indicator.

To fit diminutive size of aircraft and panel, would like to go for about a 50mm (or smaller). Again I would like the benefit of your learned experience & observations.

Make?
Model?
General comments in support/against a particular Brand/Model?

Sonex claimed airspeed range 35 knots to Vne 170 knots - I have always understood instruments of this kind are most accurate in their mid indicating range - Is this peoples experience/understanding ? If so, I guess I am looking at an ASI that indicates from about 20 knots - 200 knots - your comments?

MGL has instruments that work well. Can't vouch for the Sonex as I'm still building but I've used them in an RV with good success.

For best accuracy at low air speeds, consider adding a lift reserve indicator. No electric required.

David A.

Do you have any time in a Sonex? Its a pretty honest airplane. I do lots of flight reviews and transition training in various airplanes and have about 20 hours giving instruction in Sonex's. Did you mean ASI in the title?

I want the Pilot to be familiar with the attitude of the airplane vs airspeed. So after a little practice, one of my things it to block the airspeed from their view and do a few simulated engine outs. The lesson is usually stall/spin avoidance but I always toss in airspeed indicator failure as a talking point. They quickly adapt to the nose position of the airplane and don't have any problem landing that way. They tend to come in a little fast and float a little but if the emergency is the ASI quit, it doesn't matter since you probably wouldn't pick a short field for that situation.

DCASonex wrote:For best accuracy at low air speeds, consider adding a lift reserve indicator. No electric required.

David A.

I agree with David. I installed a mechanical LRI (Lift Reserve Indicator) on my previous Sonex and also in my current Cleanex. I tend to use them more than the ASI for take-off and landings.

Dyslexia Ruled KO !

Yes I should have put ASI

Scott Todd wrote:Do you have any time in a Sonex? Its a pretty honest airplane. I do lots of flight reviews and transition training in various airplanes and have about 20 hours giving instruction in Sonex's. Did you mean ASI in the title?

I want the Pilot to be familiar with the attitude of the airplane vs airspeed. So after a little practice, one of my things it to block the airspeed from their view and do a few simulated engine outs. The lesson is usually stall/spin avoidance but I always toss in airspeed indicator failure as a talking point. They quickly adapt to the nose position of the airplane and don't have any problem landing that way. They tend to come in a little fast and float a little but if the emergency is the ASI quit, it doesn't matter since you probably wouldn't pick a short field for that situation.

Its a nice idea - flying by attitude/power and certainly works in practice drills, however I have always been a believer in having a reasonable degree of redundancy. Taking your argument one step further - no need for a stall warning and my current aircraft doesnt have one BUT at a small extra cost a stall warning or A of A can be fitted which may just save your bacon some day. In the unlikely event of the Dynon going out on strike (completely blank panel) having a basic ASI and compass will definitely get me home without any difficulty.

daleandee wrote:

DCASonex wrote:For best accuracy at low air speeds, consider adding a lift reserve indicator. No electric required.

David A.

I agree with David. I installed a mechanical LRI (Lift Reserve Indicator) on my previous Sonex and also in my current Cleanex. I tend to use them more than the ASI for take-off and landings.

Hi David - until your comment, I hade never heard of this device - gets a good write up in Kitfox - did you purchase or make yours?

I have a UMA round gauge ASI and Altimeter and like them. The ASI is more accurate (in my installation) at cruise by about 7 mph compared to my GRT Mini EFIS.

I also have an LRI and a TinyTach on the instrument panel where ai can look out the windshield on final and see power and lift remaining. It works well for me.

If you want to build the LRI try this:

https://img1.wsimg.com/blobby/go/e83c7c ... 4222140376