Cutting out NACA ducts and air conditioning - advice please.

I'm seeking advice for two things:

1. I plan on adding two extra NACA ducts to the tailcone skin just behind the cargo door (I used the port cutouts on the forward fuselage as a pattern). I plan on piping them to Aerosport's overhead console thru an electric butterfly valve. My question is: what's the best way to cut these out? It's an odd shape with sharp corners and I want to get it as perfect as possible.

2. I've been toying with adding an air conditioning system, which will likely go in this same area. Does anyone have experience with an aircraft A/C system? Are they at all worth the extra expense/complexity/weight?

Thanx a lot-
Jack and Dave, plane building gods and chick magnets.

1. I traced the pattern onto the skin and then drilled the corners. I then cut it out slightly undersized with my Dremel and a cut off wheel. Finished it by filing it smooth to final size. The whole operation took just a few minutes.

2. Can't help you with your A/C question. David Maib has A/C in his RV-10-- you might try contacting him.

1. I did it more or less like Todd described. I used different tools, but you get the idea. I used a nibbler to cut the holes. You can get one at the leading tool vendors.

2. Depends on your primary flight area is going to be. In our part of the country, it really isn't worth the expense. Once you get in the air, you'll have plenty of air. Now if you are going to be spending a significant amount of time in the south, then clearly it may make sense.

Air conditioning

Ive got Airflow Systems A/C in my RV10. It is a life saver in the hot Oklahoma summers. The total system weighs about 35 lbs.
Details are on my website - www.nwacaptain.com
Greg....

Tip

Use the pre-cut NACA cut out that has already been punched out of the forward fuselage as a template for your cut.

In the past, another builder used his NACA "scoop" as a template and the dimension of the aft portion shouldn't be followed! Removed too much skin

David

I made a template from 3/4" plywood, cutting out the inside of the vent. Clamped it to the inside of the fues. Drilled a 3/4" hole in the skin and then used a router with a laminate bit to make perfect match.

rleffler said:

1. I did it more or less like Todd described. I used different tools, but you get the idea. I used a nibbler to cut the holes. You can get one at the leading tool vendors.

2. Depends on your primary flight area is going to be. In our part of the country, it really isn't worth the expense. Once you get in the air, you'll have plenty of air. Now if you are going to be spending a significant amount of time in the south, then clearly it may make sense.

Click to expand...

Yes, the nibbler works great.

We have no a/c or overhead vents and stay plenty cool once moving. In 90+ temps we taxi with the doors cracked 4". After takeoff at gross with the family, we are at 10,500 in less than 10 minutes. A/C would have meant leaving my aux battery out or little baggage with the family. EW= 1656.