This may be of interest to Jojo and the Lancair 320.
Interestingly, an SR22 pilot reports a 10kt loss of speed in rain.
I think that when I was looking at this, I concluded that Alpha Systems was the better product, but also that the heated version of the sensor was a must. Even a normal pilot tube will ice up in VMC, below 0C…
However I now think the Garmin one is the best one. I’ve given up on this topic for now – I just don’t think these products work for what I wanted it for – which is not what Jojo probably wants it for which is low altitude scenarios.
Thanks for all the replies!
I suppose the real issue is what do you want it to do for you?
Jojo probably wants it for which is low altitude scenarios
Yep. Low and slow, as in landing. A critical phase of flight in any aircraft, but particularly in a Lancair (if what I read is true – I have yet to fly the thing).
Thanks for the link to the effect of heavy rain on (composite) airfoils – I’m familiar with the phenomenon from flying an Aquila, although can’t say I ever encountered a significant loss of performance. I probably never flew in the kind of heavy rain which might cause that effect. There is a warning in the POH..
Rain doesn’t affect “composite” airfoils but LAMINAR airfoils ;-)
Might I suggest cutting people a bit of slack if they haven’t used the search function 
On the one hand, “everything” is already on the internet somewhere. But often there are different takes on a subject.
The search function here on EuroGA has not been great, but has recently been much improved.
I have an AOA on my EFIS in my Falco and LOVE it.
I reckon it saved my life recently when I had a genuine EFATO.
However, this last weekend I flew the Falco in the rain for the first time and on landing the AOA indicator was giving completely unreliable readings which if true should have resulted in a stall.
I reckon it saved my life recently when I had a genuine EFATO.
And what makes you think that your airspeed indicator and/or stall warner wouldn’t have done the same for you? After all, a stall warner is nothing else than a device for measuring AoA with an alarm sounding (or flashing) when a pre-set danger level is reached.
I have one for instructing. It’s even built with official (LBA) paper. (MK II mod was cutting the rope a bit)
Works perfect to demonstrate AOA changes for different phases of flight.
Rain doesn’t affect “composite” airfoils but LAMINAR airfoils ;-)
Not all of them. The GA airfoil used on the Glasair, for instance, was designed to minimise the effect of trips at the leading edge. Especially the first generation laminar flow airfoils (NACA 6 Series and many old Worthmann FX-airfoils used on first composite gliders) are quite sensitive to rain and mosquitos. Thus the invention of the bug viper.
For the NLF airfoil on the Lancair, I don’t know. However, I could just punch it in my solver and see what I’d get. You don’t fly much faster than M .3, do you?
A google on
NLF airfoil
digs out many hits. The first one is interesting:
The rest of the paper is too technical for me
However, my recollection of what I have heard about Jojo’s plane is that the Lancair 320 design pre-dates that paper by about 10 years.
