Elevator counterbalance weights

[danweseman]

Sean
you do need a balance just because you have a 0-320 . All the reasons apply to any engine. It will help shift the CG aft, but you may not want that for your mission.Also other things , like a the larger tail wheel , and battery / competent placement can adjust you CG. like all things Panther it is very versatile. The long wing limits the VNE to 200 TAS not the balence weight. Consider the the handling/ mission when deciding.

Dan

[Tony Spicer]

Note that Dan said in his post that he would be covering the subject in more detail soon. If you want a head start, have a look at this:

http://www.flyingmag.com/technique/prof ... ling-lucky

As a point of reference, neither the Sonex nor the RV-3 have balanced elevators. Vne for the Sonex is 197 mph and for the RV-3 215 mph.

Stand by for Dan.

Tony

[Lowrider]

Thanks Tony!

Maybe I missed something but does that mean that flutter can only occur about 200 mph?

[Tony Spicer]

How does not having the elevator counterbalances affect potential flutter?

You'll find the answer here: http://flywithspa.com/panther-specs/

LSA, no counterweights, Vne is 200 mph
Sport, counterweights, Vne 220 mph

[Lowrider]

Dan,

How does not having the elevator counterbalances affect potential flutter?

[Seansull]

Thanks Guys,

Since I am going with the o320, I need the counterweights correct?

[danweseman]

Sean
These parts are intended for and include with the Sport version (short wing) kit.
Rigging 1 section 5 has details on when why to use the weights. Note with the long wing the do not increase the VNE.
A few other thoughts

1.They add about 6 lbs to the aircraft in the tail. this ha a large effect on CG. if you intend to use the plane more for sport touring, and less for rat rcing and acro , then you may not want the weight. This will help maintain a forward CG and better utilize the baggage area.
2.they lighten the "stick force per G curve" of the control system. Meaning they feel about like the spring at 1 g but as G builds the force dosen not build as quickly. The yank and bank guys will enjoy it cross country guys may not.
3. The panther being light is easily effected by CG. As the CG goes aft the Panther will be more pitch sensitive and less stable. At around 28% it is fine, but as you approach the rear limit of 30% it tends to be more neutral. This is very common on all aircraft of this type. If you combine the light forces of the mass balance with the aft CG the effects are much more noticeable.

This will be covered in more detail in a post to builder soon
Dan

[wmensink]

Sean,
I believe it is one of the many options but it not part of the standard kit. Suggest an email to Sales to start a work order with request for the parts to install the elevator counterweight option. If memory serves me right,I received one triangular lead weight similar to the aileron counterweights and two custom formed aluminum bars. The bars should be predrilled to match the holes in the counterweight but you need to custom fit using a shim to insure clearance from your pushrod and also insure full travel in the tail space before drilling through the tabs on the elevator horns.

A very easy installation but do watch your trim cable routing to clear the counterweight also. The newer Builders Manual probably has all this in there and I just wasted a whole bunch of electronic ink. This may be one of the spots where an angle drill or snake drill justifies its place in your toolbox.

Will Mensink

[Seansull]

Are the elevator counterbalance weights not part of the kit? If not, what parts do I need to order?

Thanks!