[vansrv8]

As most of you know that fly aerobatics in the 8, it can be a real piggy with the forward CG and nothing in the back.

My aero flightss are typically 1/2 tanks, me and 5 gallons of smoke oil in the front baggage compartment; this gives me a CG of 80.36 ". As you know the stick forces can be high.

With the 140 lbs of 'supreme boss' in the back, the CG is 83.64 " and the aerobatic stick forces are pleasant.

Question to the masses: does anyone use ballast in the aft baggage compartment or other areas to have this nice stick feel when solo? What are you using, how are you securing, and are the gotcha's ?

 

[Toobuilder]

Lots of prior discussion on this exact topic if you do a search, but yes, people will ballast to get a feel they like.

FWIW, I like "light" better than a light "feel" so, I dump as much weight as I can when out fooling around. Often at the expense of a way forward CG.

 

[Low Pass]

Lots of prior discussion on this exact topic if you do a search, but yes, people will ballast to get a feel they like.

FWIW, I like "light" better than a light "feel" so, I dump as much weight as I can when out fooling around. Often at the expense of a way forward CG.

Same for me. I'll gladly work my arm a little harder knowing the wings are working a little less. For comparison, my acro is very mild and "RV". My loops aren't round and my rolls aren't constant altitude. But they make me happy.

 

[Nate-ISU]

My loops aren't round and my rolls aren't constant altitude. But they make me happy.

Sorry to veer off topic but as a first time owner and newer to the RV world, bravo for being able to put into words my last ~50/hrs of RV time. I tell myself I need to perfect the art but dang do I have too much fun just FLYING.

Carry on!

 

[humptybump]

Ken, if I flew with half tanks and 45lbs of forward baggage, I'd have 80.17. I have nothing in the forward and more fuel so I'm at around 80.8 at 1475lbs. I fly like this all the time and for pretty much everything. I've never noticed any adverse behavior.

 

[panhandler1956]

Ken,
I have a heavy angle valve and hartzell out front, plus inverted oil. I have a hard time holding inverted flight without ballast.

Conversely, I don't like how it flies when it gets too far aft (still within the envelope). Flying at the aft limit makes it fly great, but my landings are "interesting."

 

[Traash]

Put the smoke oil tank in the rear.

 

[vansrv8]

'Conversely, I don't like how it flies when it gets too far aft (still within the envelope). Flying at the aft limit makes it fly great, but my landings are "interesting." "

I agree completely. Landing with a full load and rear Cof G makes it a different beast

"Put the smoke oil tank in the rear. "

I do not consider this a viable option as a "fixed" item. It would limit my passenger carrying ability to the extreme. I went through the pros and cons of this when building the smoke system and chose the foward baggage compartment for a few reasons, namely removal and install in less than 3 minutes and minimal impact on CofG with full and no oil.

The 8 is a wonderful airplane and I see that someone in the UK was/is setting one up for rear seat solo...that would be the ticket

 

[Eddie P]

I know this is probably not a great option for some folks but I was wondering about the possibility of using a ballast station somewhere in the empennage area that would allow adding say, 5 or so pounds, to be bolted into the area to effectively bring a solo CG to a more neutral location. (i.e. Solo Aerobatic Kit - Remove before carrying passengers!) Anyone out there doing this already?

I am not sure but there would probably be significant structural considerations to ponder - would not be advisable without calculating the engineering particulars first. It would require far less weight than the alternate plan of adding ballast strapped into a rear seat or baggage bay to achieve the same CG shift and might actually pose less of a risk as the lighter weight attached more semi-permanently could be considered more secure under aerobatic loads. The real threat for operations would be if someone did this and then inadvertently later loaded the plane close to aft CG while forgetting to remove the ballast, hence being way aft and probably ending badly. Would it be worth considering to save 50 pounds of weight strapped some where else? Probably not for most people but I am curious because if someone really enjoyed solo aerobatics it might be a good option to get the stability/control/all up weight in an optimum range.

I managed a biz jet years ago that often required significant ballast in the aft cargo bay (in the tail) to be within CG when flying higher passenger counts with low baggage weight. If we flew an empty leg afterward we would be very aft so we had to shift the ballast in that case.

 

[Toobuilder]

I know this is probably not a great option for some folks but I was wondering about the possibility of using a ballast station somewhere in the empennage area that would allow adding say, 5 or so pounds, to be bolted into the area to effectively bring a solo CG to a more neutral location. (i.e. Solo Aerobatic Kit - Remove before carrying passengers!) Anyone out there doing this already?...

There's been some prior discussion on this as well. A couple of years ago I presented the idea of a quickly removable 3 inch dia slug of lead that would reside in a tube under the empennage or under the pilots seat, depending on the mission. I never did it on the -8, but after flying the Rocket a bit, I'm starting to look at it again.

 

[Kyle Boatright]

FWIW, I like "light" better than a light "feel" so, I dump as much weight as I can when out fooling around. Often at the expense of a way forward CG.

The flip side of this perspective is that you're working the elevator, HS, elevator pushrods, and hardware harder.

We'd have to ask the factory which is the weak(er) link in the chain.