Do micro vortex generators slow you down?

[Thebigdill]

I hear from all sorts of forums that VGs slow down the cruise speed of their aircraft and sometimes pilots opt to remove them because of that.

After emailing Microaero.com they responded with these two messages and the attached STC documents. I thought it might be useful for the community to have this information.

(1st email)



Thank you for your inquiry. There is NO reduction in cruise speed or top speed with the addition of Micro VGs on your Cessna 182RG turbo. The small amount of drag that is created by having the VG blades installed, is off-set (and negated) by the cleaner egress of airflow (the vortices) off the trailing edge of the wing.

We have tested this effect both in the wind tunnel, and by actually flying speed runs during our flight test program for the FAA STC. The flights were conducted on an instrumented plane: at the same weight, CG loading, on the same day, with the same aircraft. During flight tests, the parts are installed with our flight test tape. This allows us to peel them off after the speed runs while refueling - before repeating the test without the VGs for comparison.

(2nd email)

Attached please find some data on a Cessna 182T. The flights were conducted at 2750 lbs, identical weight, before and after VGs. Data in this plane shows KTAS of 134 for both flights. Also attached are two wind tunnel pictures taken with and without VGs, at the same speed. The bottom of each photo is the trailing edge of the wing (boundary layer yellow) looking forward. You can see the cleaner egress of airflow off the trailing edge of the wing which off-sets the drag created by the VGs near the leading edge.

[wlloyd03]

I have had micro vortex generators on my '79 TR182 since 2013. I have not experienced a loss of speed. I have experienced much greater control at low airspeed and lower stall speed. I flew at high altitude airports in the intermountain west. They produce lift earlier in the takeoff roll. They will give you greater elevator and rudder control at low speed as well. That's code for my TR182 does not handle like truck on landing or in a cross wind. The controls are very responsive, and this will take a little practice after installation. The aircraft will tend to float longer as it takes longer to bleed off the lift. I hope this helps.

[Thebigdill]

We're flying the same year and model! Would you recommend this mod even if I'm not doing a lot of short field work? Also, what do you imagine your increase in climb rate was post install? Thanks!