To VG or not to VG

[Guest Neilm1955]

I have a Savannah that we removed the slats from. It was never flown with the slats so dont know how it handled. I have purchased a set of VG,s but not yet installed them. I have been told that its dangerous not to install them because the aircraft will tend to severley drop a wing at slow speed under power. The plane has now been flown by a number of experienced fliers all of which have taken it through all manner of stall configurations, the most recent was by an instructor yesterday. He took it to 4000ft and tried everything to make it flip over and it just wouldnt do it. He remarked on how stable it flies. My level 2 mech also tried to make it do it and it wont. So my question is why should we install the VG,s? What difference would they make to the handling seeing it is so stable?

 

I really want to know if anyone can help.

 

Neil

 

 

[Kenny]

VGs or not VGs

 

Hi Neil

 

I am a newbie pilot 57 hours in total. I too have a Savannah.

 

After Receiving my license I flew about 18 hours in my Savy with slats on before removing them and fitting VGs The one huge difference I found was landing, when landing with slats on if you flared a little high and did not get the plane down closer to the ground in time before running out of energy the slats would let go and dump you down fairly hard. With VGs if you make the same mistake the plane floats down and touches the ground a lot easier.

 

The STOL caharicteristics stay very much the same with VGs as with slats .

 

I have not flown the plane without VGs but I would imagine the stall speed would be higher as the boundary layer of air would be disrupted earlier .

 

I tried to stall the plane with the VGs on and the only way I could tell it was stalled was by watching the VSI

 

Overall I find the plane very much more forgiving and am very glad I took the slats off

 

cruise speed has increased by around 6 or 7 knots.

 

You may have already seen John Gilpin's web site but here it is if you haven't he has done a lot of testing with VGs

 

StolSpeed Aerodynamics - Performance Enhancement for Light Aircraft

 

Regards Ken