CG change

[colospace]

Just a curiosity about CG movement. Anyone know how much the CG moves when converting a Series 7 between trigear and tailwheel configurations?

[jiott]

I'll bet the CG is in a sweeter spot with the tri-gear. As a tail dragger my SS7 CG is always very much toward the rear no matter how I load it. It stays within the limits, but always toward the rear limit.

[jrevens]

I'll bet the CG is in a sweeter spot with the tri-gear. As a tail dragger my SS7 CG is always very much toward the rear no matter how I load it. It stays within the limits, but always toward the rear limit.

That's why I'm not worrying about weight in my engine compartment, Jim. No lightweight, expensive batteries for me! (No real heavy tailwheels either).
I'm hoping the Oratex will help in that regard too.

[jiott]

You're absolutely right John, however I still really like my lithium battery. It doesn't do anything to help CG, but it saves 10 lbs, which is a lot of baggage and helps make up for my heavy tailwheel. It is also nice to not have to always hook up a trickle charger because it doesn't lose 1/10th of a volt in months of sitting.

[rv9ralph]

Paul Z might be able to comment on this. He had his SS7 converted from a tri-gear to a tail wheel.

Where are you Paul Z?

Ralph

[HighWing]

For five years I worked on the ramp at KSFO,s United Airlines ramp area. This was a few years after the Arab Oil Embargo. I found it curious that they would load every departing flight to nearly the aft CG limit. I learned that during the embargo anything and everything that would improve fuel economy was employed. Aft CG is very efficient. Improving airspeed and or economy depending on one's preference.

[Dave S]

An aft CG, within operational limits at the same loaded weight, also allows a slower touchdown speed and slightly shorter rollout in many aircraft...with a forward CG bias a person may run out of elevator to keep the nose up before they run out of airspeed.

[jrevens]

Yep, many aircraft display that characteristic. I know my Thorp is faster with baggage & a passenger than without.

[RobS]

A good illustrated read on the benefits of an aft CG (within limits):

http://www.boldmethod.com/learn-to-f...t-performance/

[Paul Z]

I'll have to got to the airport tomorrow to get the tail dragger weight & balance. Once I get both I'll post them.

Paul Zimmermann