Elevator balance modification

[Seal]

Information on changes to the elevator balance modification from Nick

 

 

 

We have just completed flight testing on a modification to the elevator balance. With the development of the SLSA Lightning and the mission of the aircraft changing slightly, a need to make a change to the pitch force required was noted. With the standard wing the roll to pitch force was well harmonized at maneuvering speed and below. With the addition of the long wing tips the roll forces increased but the pitch stayed the same. This resulted in a some what unbalanced feel on the stick. There are two options, lighten the ailerons, or heavy up the pitch. While the first seems the better to get a nice light stick, the over all the mission of the aircraft with the long wing tip is going to be Light sport. So with this in mind and the typical pilot than being a newer light sport pilot or those who have not flown for a while due to a medical or other issue, the thought of making the pitch heavier to harmonize the controls was the better option. We have removed the aerodynamic balance from the elevator completely. The resulting change has increased the stick pull required by a good amount. In our 2008demo the stick force required with the balance to accelerate 1g was 2.5lbs, this is measured with a digital scale on the stick in flight and not a guess. With the balance removed the stick pull required in the same situation was 4.75lbs. This with the longer wing now provides a good feel between both roll and pitch, and I feel this is better for most pilots. An additional side benefit is the elimination of the “soft†spot in the center of pitch, anyone with enough time in a lightning has most likely noticed a small spot in the middle 1†of throw on the stick were its kinda dead, so that’s gone. This is not to say with a short wing that the pitch would too be heavy if one made the modification as well, I think that it would still have good stick feel. I have updated the builders manual online to incorporate this change, it is in section #19 on balance modification. Those of you asking if the roll can be lighten up to match the light pitch feel with the balances, well still working on that but should have a solution in due time.

 

 

 

Thanks for reading my book.

 

 

 

Nick Otterback

 

Arion Aircraft, LLC