drag

[bonal]

 I am going to install a new antenna for my #2 com that had its antenna removed for the GPS antenna (not by me) that was put in its place.  I have the bent wire with the white plastic mount. i was going to install it on the belly but someone mentioned on another thread there is a higher resultant drag on the belly compared to the top and may cause a greater drop in TAS. what do you (others) think, could I see a difference in speed?  

[Marauder]

 I am going to install a new antenna for my #2 com that had its antenna removed for the GPS antenna (not by me) that was put in its place.  I have the bent wire with the white plastic mount. i was going to install it on the belly but someone mentioned on another thread there is a higher resultant drag on the belly compared to the top and may cause a greater drop in TAS. what do you (others) think, could I see a difference in speed?  

 

Antenna placement is critical for preventing interference with other antenna. I would check with an avionics shop to make sure where you place it isn't going to cause other issues. Drag being the least of them.

[bonal]

An avionics mech is going to do this install along side and we discussed the interference and that it will be going on the belly. hope it wont be slowing me down too much but I need my 2 com working. dont know why the previous owner removed the antena in the first place.

[ryoder]

I should invent retractable antennas. They come out when needed.

[ArtVandelay]

I should invent retractable antennas. They come out when needed.

Already invented, use to have one my vette, probably too much weight for too little gain

[ryoder]

Yeah. My Vette has an inside antenna.

There is a ton of drag on an antenna though. Watch the old YouTube video someone posted on here. It will blow your kid how much drag a simple wire causes.

[bonal]

Drag is appropriately named its a drag and wish there was a way to have both coms share the one antenna but I need to get my 2 com back in the game. I know the ELT antenna is not tuned right for the com but it would be great if I could put a splitter on the lead and have it do both jobs.

[Guest]

Yeah. My Vette has an inside antenna.

There is a ton of drag on an antenna though. Watch the old YouTube video someone posted on here. It will blow your kid how much drag a simple wire causes.

This is the video I suggested earlier.

https://m.youtube.com/watch?v=ftq8jTQ8ANE

Clarence

[ryoder]

Yep. That video rocks.

[jetdriven]

IIRC it was Norm, "Testwest" who told me there is a 4" boundary layer in the belly aft of the wing and a CI-122 bent whip antenna has negligible drag there. He did chastise me for the CI-196 straight COM antenna on the roof in the usual forward location. The boundary layer there is very thin and its the highest velocity airflow over the airplane, and the highest drag for anything mounted there. I think I'm gonna pull the "7" antenna off the rear upper fuselage and mount it on the bottom, and mount the CI-196 in the aft location.

 

I have removed 2 "ball on a stick" DME antennas, and a CI-122 bent whip, also a big King ADF antenna from the lower rear belly. I couldnt really quantify any real speed increase from removing them.

 

As far as antenna drag in general, I am rethinking the CI-122 bent whip.  You take the piss on the rod part but its only 4 or 5". The CI-196 is about a foot tall and you have a more optimized shape, but the base is very thick and that antenna sticks up a long way. Perhaps I should build a 170 knot wind tunnel.

[Andy95W]

This is the video I suggested earlier.https://m.youtube.com/watch?v=ftq8jTQ8ANE

Clarence

Old school. Ya gotta love it.

Damn punk kids these days, don't know nothin'.

I may have to go get another beer.