Increase GW with VG's??

[deemee boosgkee]

I noticed that on the Chieftain that with VG's installed you can increase the GW from 7000 to 7360 (give or take). Does this mean that the SE performance with the VG's is just as good at 7360 as it is without VG's at 7000?

 

[DrewBlows]

I noticed that on the Chieftain that with VG's installed you can increase the GW from 7000 to 7360 (give or take). Does this mean that the SE performance with the VG's is just as good at 7360 as it is without VG's at 7000?

Hmmmm... depends what you mean by performance. If you are talking about single engine controllability, the extra weight would actually help even without the vortex generators.

If you are talking about single engine climb performance, it's hard to say without knowing Vs0 for a Chiefton. I'm not sure how a Chiefton is certified but I could guess. The regulations say a twin must have climb performance of at least .027 Vs0 squared if it has a Vs0 of more than 61 knots (coincidentally the same Vs0 any single engine airplane must conform to). I suspect the VGs allow the Vs0 of a Chiefton to stay below 61 knots at the higher weight which means it doesn't have to have .027 Vs0 climb performance.

This website explains light twin performance pretty well.