Close up the wing, or work around the mess?

I've been dragging my feet for way too long on this, wiling away the days by reading old forums posts on the subject, so I'm hoping your collective wisdom can set me on a path.

I'm slowly building a slowbuild 7A in which I eventually intend to install heated pitot and AOA sensing to feed a glass IFR panel.

Old posts provide conflicting advice:

• Don't decide on/buy avionics (that become quickly obsolete) until the engine is hung and everything else is ready
• Don't close up the wing until you've installed your pitot, aoa, wiring, etc.
• Installing conduit or at least snap bushings and pull strings are good enough to close the wing
• Use an AOA pitot mast that performs both ram air pressure and AOA input (I think)
• Use separate AOA and pitot (?)
• AOA should be near the tiedown where the pitot normally goes
• AOA should be way outboard to avoid prop wash

If I had unlimited space, I suppose I would set aside the left wing in the stand (right wing is totally done) and deal with it in a few years, but I need to get it (and the flap and aileron taking up shelf space) out of the way to make room for fuselage construction.

Would it be totally stupid to rivet the bottom skins before installing pitot/AOA? Can I make some reasonable assumptions and run tubing? If so, how big and where? Is there a guide on this?

I'm gaining respect for the argument to avoid deviating from the plans

Thank you for your help!

Rivet the wing and move on.

I bought my 7A wings totally finished.
I installed a heated pitot, with Dynon the AOA was in the pitot tube. I drilled my holes and installed snap rings to run my wiring. My 7 is flying.

I will admit if I had built the wings and done the lighting holes etc. while building it would have been good to do. As it was, to install all the wiring and run tubes etc. was not hard to do after the fact.

Just my $.02 worth.
Dave

Opinions

[email protected] said:

Rivet the wing and move on.

I bought my 7A wings totally finished.
I installed a heated pitot, with Dynon the AOA was in the pitot tube. I drilled my holes and installed snap rings to run my wiring. My 7 is flying.

I will admit if I had built the wings and done the lighting holes etc. while building it would have been good to do. As it was, to install all the wiring and run tubes etc. was not hard to do after the fact.

Just my $.02 worth.
Dave

Click to expand...

Good $.02
I would plan a little. Plan the plumbing. Most systems combine pitot and AOA in one probe so you can run some plumbing to the bay. SafeAir is easy to use.
Install the conduit for future use.
Heater controllers vary so you would have to install the nut plates later.
Everyone has a preference for location but a majority seem to place it in the bay just outboard of the bellcrank. That's where Gretz recommends.
You could get a Gretz mast and install the base.
Close up the wing and you're set for whatever flavor you want.

ToadMan8 said:

I've been dragging my feet for way too long on this, wiling away the days by reading old forums posts on the subject, so I'm hoping your collective wisdom can set me on a path.

I'm slowly building a slowbuild 7A in which I eventually intend to install heated pitot and AOA sensing to feed a glass IFR panel.

Old posts provide conflicting advice:

• Don't decide on/buy avionics (that become quickly obsolete) until the engine is hung and everything else is ready
• Don't close up the wing until you've installed your pitot, aoa, wiring, etc.
• Installing conduit or at least snap bushings and pull strings are good enough to close the wing
• Use an AOA pitot mast that performs both ram air pressure and AOA input (I think)
• Use separate AOA and pitot (?)
• AOA should be near the tiedown where the pitot normally goes
• AOA should be way outboard to avoid prop wash

If I had unlimited space, I suppose I would set aside the left wing in the stand (right wing is totally done) and deal with it in a few years, but I need to get it (and the flap and aileron taking up shelf space) out of the way to make room for fuselage construction.

Would it be totally stupid to rivet the bottom skins before installing pitot/AOA? Can I make some reasonable assumptions and run tubing? If so, how big and where? Is there a guide on this?

I'm gaining respect for the argument to avoid deviating from the plans

Thank you for your help!

Click to expand...

Buy as late as possible. Also be forewarn, like anything else avionics can have constrained availability at times. Especially if you are hiring a panel builder. Keep in contact with the vendors to understand their lead times.

You can start building the wiring harness with out all the expensive avionics. You can buy just the trays in advance. This helps to minimize the financial risk if you decide to change something later.

No reason to wait. I believe all the popular pitots use the same mount. Put in conduit. Pull wire to be terminated later. Leave pull strings in the conduit.

AFS, Dynon, and Garmin all have combo pitots. I don't know how it stacks up with the AFS wing pressure units. give Rob a call to see if there is any difference. Not really an issue.

Just ensure your pitot is out of the way of your tie downs. I would also put it adjacent to an access panel. On my RV-10 my pitot is mount about 4/5s towards the wing tip, but I have the AFS wing pressure AOA. You want these away from the fuselage.

I left the bottom skins unriveted and moved on to the fuselage. I figure I'll wait until I've pretty well hashed out wiring and so forth and then finally rivet the bottom skins on.

I ran a corrogated black pvc conduit from the root to the tip and I burned a hole in it near where the pitot mounts. I have access to that hole through the aileron access panel (this is an RV4 but I expect yours is similar) and I have access to the root and tip. So I can run wires or tubes to and from the lights and the pitot. Then I riveted on the bottom skin. With the conduit in place I think running wires should be straight forward.

I did what Larry suggested above. However, I forgot to put in the heated pitot controller in until after the wing was closed up. I still managed to do it but the job probably would have been a little easier and neater had I done it with the wing bottom open. I used the Gretz mast and have the Dynon pitot/AOA.