Jump to content

Savannah VG problem


FernandoPDA

Recommended Posts

If the aircraft flew properly without the VGs and with slats, the issue appears related to the altered lift characteristics and/or airflow changes resulting from removal of the slats (I have assumed the slats were removed) and the addition of VGs.

 

JG (John Gilpin) - an active contributor to this group - was a pioneer with this modification to the Savannah aircraft. I suggest you address an inquiry directly to him.

 

You may have seen these articles - certainly a good place to start...

 

http://www.stolspeed.com/slats-v-s-vgs; http://www.stolspeed.com/id/26; StolSpeed Aerodynamics - Performance Enhancement for Light Aircraft (the latter two links connect to JG)

 

Wish I could offer more.

 

Fly safely.

 

CanadaDan

 

 

  • More 1
Link to comment
Share on other sites

If the aircraft flew properly without the VGs and with slats, the issue appears related to the altered lift characteristics and/or airflow changes resulting from removal of the slats (I have assumed the slats were removed) and the addition of VGs.JG (John Gilpin) - an active contributor to this group - was a pioneer with this modification to the Savannah aircraft. I suggest you address an inquiry directly to him.

You may have seen these articles - certainly a good place to start...

 

http://www.stolspeed.com/slats-v-s-vgs; http://www.stolspeed.com/id/26; StolSpeed Aerodynamics - Performance Enhancement for Light Aircraft (the latter two links connect to JG)

 

Wish I could offer more.

 

Fly safely.

 

CanadaDan

I'm already in direct contact with Fernando, trying to figure what's happening here. Never heard of similar results in any of the many conversions done....

 

JG

 

 

Link to comment
Share on other sites

I'm already in direct contact with Fernando, trying to figure what's happening here. Never heard of similar results in any of the many conversions done....JG

We're interested to know what you find, if you're able to share it...

 

 

  • Like 1
Link to comment
Share on other sites

Is it the stolspeed conversion that retains the original wing cord and profile with just the slats cut off or the 'official' one that has a changed profile and slightly larger wing area with a completely new leading edge?

 

 

  • Like 1
Link to comment
Share on other sites

As a textbook warrior, I would expect that removing slats and installing VG's may move the centre of lift of the wing slightly rearwards. I would start with basics. recheck CG, as it may have been near forward limit which worked OK with slats, but now with CL moved rear, may be out of CG range. As you suggested other culprits could be flap setting, elevator trim/incidence setting or engine incidence. Running out of elevator authority at low speeds could be serious. Good luck and please tell us what you discover.

 

 

Link to comment
Share on other sites

  • 1 month later...

Today the weather was good and we were able to fly the Savannah VG.

 

Previously, we had set the flaperons with the ICP tool.

 

The change in the plane is great, now it flies perfectly level.

 

Many thanks to all, especially to John Gilpin.

 

 

  • Like 5
Link to comment
Share on other sites

Today the weather was good and we were able to fly the Savannah VG.Previously, we had set the flaperons with the ICP tool.

The change in the plane is great, now it flies perfectly level.

 

Many thanks to all, especially to John Gilpin.

Hi, Id be very interested to discover what the problem was and how it was solved. Thank you in advance. Cheers

 

 

Link to comment
Share on other sites

Hi, Id be very interested to discover what the problem was and how it was solved. Thank you in advance. Cheers

The flaperons were set incorrectly, with some downward droop. When he got the ICP jig to set them properly, all came good.

 

 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...