Originally Posted by sblack
I would like to have all my antennas internal to minimize drag. I know there is not a huge drag penalty for a com antenna by itself, but if you look at those people who have tweaked and tuned their airplanes to increase their performance the first thing they do is to fair in everything possible and get rid of any protruding things that they possibly can. Between the transponder, elt and com antennas there is a non negligible drag penalty.
Ok - but perhaps you can achieve your objectives via a different path. For example:
- Wingtip comm antenna - it will work far better than one on the rollbar.
- ELT antenna under the eppenagge fairing (I did this on two planes - works well).
- Blade transponder antenna - the drag from this antenna at even the best RV speed would be hard to measure in a instrumented wind tunnel.
But when you do all this I suspect your find traditional drag reduction efforts to have better results. For example:
- Really make sure your rigging is right. I’ve seen a lot of RVs with rigging that simply scream of added drag.
- Engine cooling air. Do you have too much? Is the air your are taking in cooling the engine or just leaking by and adding drag?
- Have you adjusted the HS angle of incidence? If you cruise around with the elevator trailing edges down from perfect neutral, your HS is inducing too much downward force. Careful here - a 0.040” shim under the HS forward spar makes a big difference.