Smoke System

[Bob Ellis]

Hi Allen

Unable to directly help you as you have a battery in the rear so I post this to help others. I was the "someone in the UK" Andy referred to in his previous post and I have taken his advice for the reasons he listed.

I am awaiting modifiaction approval from the UK auhtority of a tank that I plan to attach to a modified rear battery tray. This will be custom made along the same design as the wing tank and will have an access door on the right fuselage skin to reach the quick connect fitting for filling/draining it will also serve as an inspection port for the tank & pitch servo.

I will buy the "everything but the tank" kit from Smoking Airplanes and John has been most helpful with any inquiries - the kit also appears to be very professional in every sense.

If I use the tank as a ballast for aerobatic competitions (no smoke) then if I need to carry a rear seater my plan will be to pump the contents of the tank to the exhaust, or drain, and collect in a plastic container that will fit into the forward baggage bay.

I chose the rear battery location because it is a strong point and will not compromise baggage space or contaminate the baggage bay. It will hold about 12-13 litres - enough for about 4 mins smoke which should be OK.

I will post the details (photo/drawings/mod proposal) on my website on the Mods page later in April, as I am away from home.

Bob Ellis
Fuselage kit - 30% complete
www.rv-8.co.uk

[a25afm]

I installed my smoke system in the rear cargo compartment. Works great.

[ronschreck]

Originally Posted by Andy Hill

I've been through this RV-8 smoke system forward or back debate with someone in the UK

The answer to me would rely on "when" / "what" the smoke system is for. If it was for proper display work, which by most definitions requires you to fly minimum crew i.e. solo, and that display is aerobatic, then it really has to go in the back. Reason(s) The RV-8 (as any aircraft) gets heavy on the controls with a forward CG, so the Smoke system would oppose that. This assumes that when not displaying and, say flying dual / carrying baggage, the tank is empty, and maybe even parts of the system are removed.

If, OTOH, you mostly fly dual, smoke or no smoke, forward might best for reasons stated above i.e. less effect on CG.

Andy Hill
RV-8 G-HILZ

Andy,

I respectfully disagree. I use the smoke system when flying formation and in this instance it is preferable to have the CG more foreward as this lessens the sensitivity of the elevator, making formation flight much easier and definitely more pleasurable. I also use the smoke system during solo aerobatics:

http://www.youtube.com/watch?v=eFAIvw6_82c

I would hesitate to do aerobatics with the GC anywhere near Van's published aerobatic limit. That is a mater of safety.

As I mentioned before, with the smoke tank in the front baggage compartment it is easy to adjust the CG with balast in the rear compartment in order to put the CG right where you want it. This is not so easy with the tank in the rear baggage compartment.

[panhandler1956]

Ron,
Good input. That's an interesting perspective on formation flying, which I plan to do with my ship. I did notice you have a 200WW vs the Hartzell which might affect the results of putting the tank up front vs the rear.
I have no experience with this and I'm still looking at my options on this issue.
Regards,

[Andy Hill]

Hi Ron...

I respectfully disagree. I use the smoke system when flying formation and in this instance it is preferable to have the CG more foreward as this lessens the sensitivity of the elevator, making formation flight much easier and definitely more pleasurable

No problems... we each have our priorities and preferences

In addition, as the last post says, it depends on where your Basic CG is. Ours is 78.59". I have no hesitation myself at flying aerobatics at the Van's aft (aeros) limit but, as you say, you need to be aware of the consequences. The RV altogether is not a good aerobatics trainer (low VA, too slippery), and less so as CG goes aft. But that also means it is more fun to fly

Formation Aerobatics highlights to me the problem further... when you're now pulling up for loops at, say, 190K rather than 140K. It was both tiring / a lot of effort to "pull", both as lead and #2, which affects smoothness. The "ballast" I now carry reduces that effort considerably See Link / Link 2 / Link 3

Andy
RV-8 G-HILZ

[klovning]

Originally Posted by a25afm

I installed my smoke system in the rear cargo compartment. Works great.

I didn't realize that you could do a peel-out in a plane, I thought that was only for motorcycles and drag-racers

[DanH]

Originally Posted by N24YW

A fellow builder made this tank for me. It holds a little over 2 gallons.

Two gallons of oil, an aluminum tank, and no firesleeve...all firewall forward.......hmmmm...