De-antenna a plane

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docmirror

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The plane I'm getting has some older antennas, and some that may not even be needed anymore. I am thinking of removing them to pick up some speed, or changing to a low profile, low drag option. I'd prefer to completely remove them and go with an internal antenna. Also want to remove the old large rotating beacon and just go with a wing tip colored strobe for nav light.

Anyone ever been involved in removal of antenna? I'm sticking with one comm and two navs. I have an internal GPS remote antenna that will stay. This is just for the reduced drag.
 
not really sure what you're asking. If you don't want an antenna, take it off. the only issue you'll have to deal with other than filling the hole, is that many of them might be factory and you're going to have tome painting to do.
 
btw be sure to get a before and after measurement as best you can. A few years ago I cleaned up the mess on the belly of my plane. It had the ugly MB in the photo, a mast left from a long wire gps, and vent tubes from some fuel tanks that are no longer there. Based on 3-course gps at 10K ft it picked up 4-5 mph. Not much but noticeable, enough to push me over 165kts true which is a psychological victory when you're flying behind little 4-bangers.
 

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I always wondered how we got around 91.405 with those inoperative antennas and LORANs.
 
kgruber said:
91.405 is just ignored by maintenance people.
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(c) Shall have any inoperative instrument or item of equipment, permitted to be inoperative by §91.213(d)(2) of this part, repaired, replaced, removed, or inspected at the next required inspection; and

What makes you think we don't inspect them?
 
Tom,

I'd like to see just what the FAA means by "inspected." To my mind, admittedly getting feeble, it means required inspections due to AD or service manuals.

So that an appliance would be "inop" until inspection. But after the inspection it would be operable again. It would not apply to an appliance that will NEVER work again.

I do know that battery temperature monitors for NI-CAD batteries are required to be removed when going to lead acid in a Lear Jet. At least, the way our maintenance facility read the reg.
 
docmirror said:
The plane I'm getting has some older antennas, and some that may not even be needed anymore. I am thinking of removing them to pick up some speed, or changing to a low profile, low drag option. I'd prefer to completely remove them and go with an internal antenna. Also want to remove the old large rotating beacon and just go with a wing tip colored strobe for nav light.

Anyone ever been involved in removal of antenna? I'm sticking with one comm and two navs. I have an internal GPS remote antenna that will stay. This is just for the reduced drag.
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Reception probably won't be as good with an internal antenna. And if you're thinking of using the same antenna for both comm and nav, an additional issue is that ground stations generally have the signals vertically polarized for comm, and horizontally polarized for nav, so depending on which orientation you choose, one or the other will be further compromised.
 
Can we leave the FAR minutia for another thread, and focus on the process please?

Jeff provided some nice pics, and some good info on speed improvements, which is my goal. It's nice to know that I'm at least on the right track.

Now, what I guess I'm hoping for in a bit more detail is someone who's gone to an internal antenna, or has chosen a better type of antenna, or changed mounting, or any kind of advice on how, where, to mount them. I wasn't aware of the orientation of the two antenna modes for comm and nav but I recall that my nav antenna is mounted horz and my comm sticks upright. Makes sense now.
 
All the antennas are internal on my Tango. No issues with reception or transmission that I've noticed. However, the Tango is a composite aircraft. Putting antennas inside a metal aircraft could be problematic.
 
Anymouse said:
All the antennas are internal on my Tango. No issues with reception or transmission that I've noticed.
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Ditto my (wooden) Fly Baby. 'though I did throw caution to the winds and install the transponder antenna externally....

Ron Wanttaja
 
When using a handheld navcom inside a metal plane, I have found that the best results were obtained by attaching the "rubber duck" antenna to an extension cable that had a suction cup, and mounting it on a window that was facing the station I wanted to receive and/or transmit to. I also chose the orientation according to whether I was using the nav or com feature.

If it were me, I would remove unused antennas, and if the plane has a metal fuselage, I would leave whichever nav and com antennas were still being used on the outside.
 
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wanttaja said:
Ditto my (wooden) Fly Baby. 'though I did throw caution to the winds and install the transponder antenna externally....

Ron Wanttaja
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I gotta small blade txp antenna that I'm looking forward to using. Other than that I think I'm gonna clean all the others off and go internal. If I loose some VOR volume I can live with it unless it's really poor, and then I'll have to see about a pair of those blade kind for the tail area.
 
docmirror said:
Can we leave the FAR minutia for another thread, and focus on the process please?
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The process of removing the antenna is to remove the hardware that is holding it to the skin, and either patch the hole or replace the sheet of skin where the hole is. The later can get quite involved. Some times getting the cable run out of the aircraft gets difficult, I've seen occasions that the entire interior had to come out.
 
There's one patch on the roof with some screws in it. It also has a recess where the patch is inside the skin. I'm gonna redo that completely cause it looks crappy. I want a dual plane Al patch with the surface flush, and use flush rivets.

The only thing I want left is the TXP blade antenna. I'm also gonna remove the retract step as all it does is cause problems. Flush patch that too. I'll carry a small plastic step for short folks to get on the wing if needed.

I want to get back to Beech specific profile when they certified the plane, except for the higher HP engine of the later model. Hoping to get back my 185MPH cruise of the last one I had. Even though I never run at that high power, I want the low drag gains at 55% power.
 
doc, be sure to read the discussions inthe beechlist archives about the angle to put the VOR blade antennae, if you are going that route
 
docmirror said:
I gotta small blade txp antenna that I'm looking forward to using. Other than that I think I'm gonna clean all the others off and go internal. If I loose some VOR volume I can live with it unless it's really poor, and then I'll have to see about a pair of those blade kind for the tail area.
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If I were considering using internal antennas for nav and com, I would delay removal of the extrerior ones and the patching work until after I had thoroughly tested the interior ones in flight in their final mounting positions. That way, if it didn't work out, considerable work and/or expense would be saved.

By the way, the blade type antennas are designed for the much shorter wavelengths that transponders and DME units use. I would not assume that they would work well, if at all, on the wavelengths used by com and VOR equipment.
 
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Palmpilot;140418By the way said:
I think the blades he is talking about are the horizontal blades that are the aerodynamic version of the towel bar nav antenna.

However, as I said earlier, all discussion is futile until we have an idea of the airframe he is talking about.

Jim
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weirdjim said:
I think the blades he is talking about are the horizontal blades that are the aerodynamic version of the towel bar nav antenna.
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When he mention a "txp" antenna, I thought he was talking about the ones used for transponders, which operate at a much higher frequency than VORs do.
 
JHW said:
doc, be sure to read the discussions inthe beechlist archives about the angle to put the VOR blade antennae, if you are going that route
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I'm denied there. Might be of some value, but sigh - not gonna happen.

Also, I've confused a few by mentioning two different antenna functions in the same post I think.

The txp antenna is a small blade, about 4" which provides propagation for the transponder(txp), and is often mounted on the belly near the front seats.

The blade antenna(s) are a pair of streamlined VOR units that mount on both sides of the rear of the fuselage and make up a dipole which receives the nav freqs.

both of these are quite aerodynamic, and still provide good reception/transmission capabilities.
 
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Since you are clear on the difference between the two types of blade antenna, no worries there.
 
docmirror said:
Other than that I think I'm gonna clean all the others off and go internal.
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Since there is a lot of talk about the Beech family, I'm going to presume a V35 or A36 or some variant thereof rather than a Staggerwing or Travel Air.

Therefore, a metal skin airplane, and so, I'd like to know how you are going to do internal antennas inside of a Faraday cage?

Jim
 
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