fairings optional?

[delusional]

I'm just starting on the emp. but I see a possible weight and balance issue down the road already. Thinking of an injected O-320 with a wood fp prop on my RV9 conventional gear configuration, taildragger if you like. I'm worried I could wind up at the aft cg limit with any baggage and figure now is the time to start heading that off.

So can I leave off the fairings on the tail? If so will Vans credit me? Any other tactics for keeping the tail real light (maybe a titanium tailwheel , or is there some other item that could be moved forward? Lights can go in the wings only I think. How about landing/taxi lights in engine cowling?

I am philosophically opposed to ballast and willing to pay in sweat or dollars to avoid same.

[AX-O]

If you leave them off, you will still need to cover the ends somehow (or the drag will hurt your performance). You would not be saving much weight if any at all. I would strongly advise you to use the counter balance weights.

If you want to keep the tail light, don't use 10 lbs of primer on the inside then prime the outside and paint 3 or 4 coats of paint.

Vans will credit you for the parts that you don't use up to 2 years. If you want a light tail wheel, get one from Dayton (read post #64) http://www.vansairforce.com/communit...t=39772&page=7

You can put your lights on the cowling if you want but people went away from that a long time ago. It adds complexity to installing and removing the cowling. However, the worst part is that the vibration really diminishes the life of the light bulb(s).

Good luck with your build.

[nucleus]

I haven't weighed my tail fairing, but it can't be a pound even. Fuel injection adds some weight. Things to bring some weight forward: Battery mounted on the firewall, oil cooler shutter, balance your main gear fairings, noise insulation, carpet, rudder pedal extenders, spring in the heat muff, more fuel, and best of all; put in heavier avionics!

Just don't leave off your fairing, please!

Hans

[n5lp]

Originally Posted by delusional

... I'm worried I could wind up at the aft cg limit with any baggage and figure now is the time to start heading that off.

So can I leave off the fairings on the tail?...

As the manufacturer, you can leave off any fairings you choose to, but if that is what you want to do you might want to examine if you are building the right airplane. With a Breezy, fairings are meaningless, but the essence of an RV is that it is fast and streamlined and beautiful, among other things. The tail fairing has an excellent benefit to weight ratio.

If the idea of an X-1 with struts doesn't bother you, go for it!

[AirbusPilot]

Here in Chile we have two RV-9A flying with the very light Lycoming O-235 and Sensenich fixed pitch prop, so if those planes didn't need any modification to get the right weight and balance, I don't think you are going to have problem with a IO-320.

Cheers,

[RetiredRacer]

The 0-235 and 0-290 engine mounts are longer to move their liter weight further forward.

Richard I sent you a PM

[videobobk]

One thing to do is to cut the optional lightening holes in the VS spar. Also when you remove excess weigh from the elevator counterbalance, remove it from the back edge. You will have to remove more that way. A manual elevator trim adds a pound or so, but MAY move the CG forward a little. Don't overdo the primer! All this helps a little, just like leaving off the fairing, which is a pretty bad idea, IMHO.

My 9A is light, has an O-320 and Catto three blade. I was surprised that the CG is well within limits, no matter how I load it. Build on.

Bob Kelly

[delusional]

That's encouraging but the nose wheel and associated parts must weigh close to ten pounds and a tailwheel and associated fasteners etc. must be a few pounds at least and that's a pretty long arm to move those parts across..

I wonder if anyone has a tailwheel RV9 with IO-320 and fp prop and would share their W&B?

I'm glad I posted here; I would never consider leaving off the couterbalance weights but I didn't think of which area of the weights would be best to shave, and I hadn't heard of any optional lightening holes yet. I guess I need to keep reading...

The seven glass fairings in the emp kit weigh almost five pounds and admittedly look fabulous. If I made some from .016 they wouldn't look nearly as nice and might cost a tiny bit in drag, but I bet I could save two or three pounds. My design objectives are:
-safe and reliable for short IFR trips, less than 300nm with two adults (okay, chubby adults) and some bags
-low operating costs
-faster than a rented Skylane

I think I'd place climb perforamce above cruise and thus willing to give up a few knots on the top end to save some weight and possibly make the W&B puzzle a little easier.

Thanks to all!

[Steve]

If you just covered the ends of the HS, VS, elevators, and top rudder opening with aluminum sheet, the plane would have the appearance of a Mooney. I would still install the bottom rudder fairing, tho.

Any RV-9 will outclimb, outrun, and burn way less fuel than a C182. Think 150kts ground speed vs 125 and 8 gph vs 14. However, you just can't beat the 182's payload.

Touchy subject alert:
As our personal weight increases toward 200 pounds and beyond, the RV appears to shrink. 'Ol Van is a skinny guy and he designed to plane to fit his frame. A 300 mile trip should take about 2 hours. That's about my limit sitting in a 40 inch wide box with another person overlapping my side of the plane.

[SteinAir]

Richard,

Going through the same thing...here are a few things we're doing. I wouldn't leave off the fairings just because the weight is so negligible...and you still need to do something to cover up the ends anyway. It's likely that whatever you come up with won't weight any less than those pieces of fiberglass.

Next, put the battery on the firewall and use the bigger battery. Use a James Extended Cowl and then get a heavy spacer (adds more weight and moves the prop forward another 2"). Use the new DJM tailwheel which saves weight. If need be, go to a Landol balancer (which is good with wood props anyway) and you should be good to go! If you still need weight, you can always throw on a prestolite starter or one of the other heavy starters...not as good as B&C's, but they work and they add weight.

Of course, there is always the option of added 10 more pounds by putting a 360 up there....but I don't want to be responsible for starting that tangent of a discussion!

Cheers,
Stein