T-45 Vortex Generators anyone?

[jetpltrich]

About a month and a half ago I contemplated adding vortex generators to my T-45 to eliminate wingtip stall on landing and buffeting of the horizontal stabilizer during a high rates of turn. Horizontal stabilizer buffet is something the real plane suffers from and I was surprised to learn this from some of the F-18 pilots I flew with that the T-45 has this issue.

Based on the testing with the OV-10 my installation resulted in this configuration:




Today was the first chance I have had to test fly this modification. As you can see gone is the Freewing vortex strip more like a spoiler in my opinion.

The first thing I noticed right after lift off was how rock solid the aircraft was, the control authority was extremely crisp. Mind you I changed none of the control parameters primarily to see the difference. The first tight turn exhibited no buffet. I then went and made an even tighter turn attempting to rip the wings off and it was out of this world how tight it was, unbelievable. After about 3 minutes of this yanking and banking I entered the pattern for some touch and goes and boy was I surprised. A nice stable approach at a slower airspeed than before and she settled into the landing extremely nice. Two more takeoffs and landings exhibited the same.

I thought I’d share this with you folks. I do believe the wing has been vastly improved.

Rich

[SanExup]

You added them to the underside of the horizontal stabilizer? Or both top and bottom?

[jetpltrich]

You added them to the underside of the horizontal stabilizer? Or both top and bottom?

just the underside.

[SanExup]

Interesting!

[Joehockey]

I did a lot of research on the VGs for problematic prop warbirds that were known to have bad wing washout designed into the kit. Examples noted by others on RCG were the Top Flight 60 size Bearcat, P40 and some other kits.
Lots of experts ( lol )love to swear they do nothing , they are silly , ridiculous and so on.Then I started to look for real pilots and videos from real pilots.
The best example ever, was a guy flying a high wing stol plane and intentionaly stalled his aircraft at safe altitude and the plane stalled at 215 MPH land speed.
He landed , returned to the shop and they added the VGs to the leading edge ahead of the ailerons ( full length ) of the ailerons only.
The pilot does the same test and now the plane stalls at 180 MPH ( wow) 35 miles per hour increase in wing performance/stability.

So I tried them on a TF Bearcat 60 size as my first test . The model was so stable it would not land . It was so stable at slow speeds it was a fun amazing warbird and with proper painting the VGs blended right in. See my pics on the P40 , they simply look like they belong .These are a great aeronautic discovery that really work

[SanExup]

Joehockey Something is a little off in the stall speeds of the STOL plane your speaking of. But I get your point.

The science behind the Vortex generators does make sense. I have always wondered if the effect scales down or not to rc planes. I imagine placement/location is important for the amount of lift or drag generated. But I can see how in a jet it could provide stability. Stol aircraft in RC scale generally have a not so scale power to weight, and a not so scale wing loading, that the benefits might go unnoticed.

The part I find most interesting is the possible effects on the jets aerodynamics. And how they might provide some stability. Maybe not huge gains in terms of a lowered stall speed but probably providing a lot more stability in slow flight and maintaining effectiveness of control surfaces across the whole surface at threshold speeds. Very cool.

[Joehockey]

I am not an engineer so my explanation may not be clear .
I will do my best to explain what a real pilot at our field said that made it super simple .
The VGs increase the efficiency of the wind over the wing.
So duplicate airplanes with aspects equal, but one had VGs , the plane with VGs under equal environmental conditions will can fly at a slower speed before the wing will stall vs the wing without the VGs .
Great videos on YouTube showing live examples