Wing root fairings

[Bryan Cotton]

If you don't have to reduce the amount of fuel you carry by adding weight that makes you faster, then it is definitely worth the trade. Question is are you that light or just willing to add that much to your personal gross weight. It's a game we all get to play.

[Skippydiesel]

If you don't have to reduce the amount of fuel you carry by adding weight that makes you faster, then it is definitely worth the trade. Question is are you that light or just willing to add that much to your personal gross weight. It's a game we all get to play.

So true!

I would not have thought that well made composite fairings would add much weight.

In the end it all comes down to how much is gained (speed) for what loss (energy required to sustain lift).

I hope that there is a Sonex owner out there, who has "been down this track" who is willing to speak of his/her experience (who is Mike Smith ?)

[Bryan Cotton]

So true!

I would not have thought that well made composite fairings would add much weight.

(who is Mike Smith ?)

Weight adds up mercilessly. Much like calories. It's just one cookie. I suspect that all the heavy Sonexes have lots of that going on - I'm going to add this, it doesn't really weigh anything. I'm guilty and we ended up over 670 lbs empty.

Mike Smith is one of our forum members and you will find his posts all over the forum. Check out the link karmarepair provided about Mike's wing root fairings.

Each pound of weight I remove from the airplane adds about 4 miles of range - or reduces range by 4 miles if I add a pound.

[Skippydiesel]

Yes I looked at the Mike Smith video - definite improvement in air flow, however he is ambivalent about any performance gains.

I would also make the point, that MS's fairing is only a trialing edge job - what of the leading edge?

On the weight gain topic - valid points all -When I tour I will be TO at max weight, so any additional airframe weight will have no impact on TO/Cruise weight but will impact negatively on items that I can carry for personal maintenance (clothing/food/etc)

[Skippydiesel]

An other aircraft forum reminded me of Mike Arnold & his AR5:

https://airscapemag.com/2016/12/05/arnold-ar5/

[Skippydiesel]

An other forum reminded me of Mike Arnold & his record breaking aircraft, AR-5:

https://en.wikipedia.org/wiki/Arnold_AR-5
https://www.youtube.com/watch?v=rxvoDbZpoY8

All you ever need to know about applied aerodynamics ?

[Skippydiesel]

Just a follow up;

It would seem that no Sonex builder/pilots/factory have explored the installation and performance gains/losses of wing root fairings, with the exception of Mike Smith's flap/fuselage trailing edge ones.

As I understand the Mike Smith modifications - They would appear to smooth out the airflow, in the area of the flap/fuselage intersection. I assume this must reduce drag but the question remains by how much?

I understand a wing root fairing, to go from just in front of the wing leading edge OR from mid span, to about the same aft/trailing position as Mikes innovation.

Given the maturity of the Sonex design it seems likely that someone would have gone down this path and have some data to support/oppose the concept being applied to this airframe.