VGs do they work? We interview an expert.

One of the 172Ms that I did my flight review in last summer had them. The other did not. The one that did got off appreciably shorter and simply would not stall.
 
Thanks for the vid!

How slow is slow enough where VGs won’t help?

They obviously don’t work at 0 kts, but if someone had an already slow flyer, would they still help with control surface authority, if not stall speed? I know, tough to answer on an online forum.
 
455 Bravo Uniform said:
They obviously don’t work at 0 kts, but if someone had an already slow flyer, would they still help with control surface authority, if not stall speed?
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Depends on if and where separation is occurring. If the flow is still attached at the control surfaces VGs won't improve control power. If separated, they might, regardless of the speed. If completely separated they probably won't help much if at all, and placement to hit the right amount of separation at the right condition is one of the dark arts of VGs.

Nauga,
from giant plates to little mylar dots
 
I have flown two 180 HP Cessna Aerobats towing gliders. Both have full STOL kits installed. One also has VGs installed, the other doesn't. I honestly don't feel any improvement in the slow speed handling from the addition of the VGs combined with the STOL kit compared to the Aerobat with just the STOL mod. The one difference I do notice is the Aerobat with the VGs has a very distinct pitch down moment when slipping with flaps. VGs may be great on an unmodified wing but I would never add them to a wing already modified with STOL STC; in this case, more is not better IMHO.
 
Micro Aero started doing VG kits for twin engine airplanes for the Vmc advantages. I think he told me the first single engine airplane he did was a Cub that kept losing one of the Alaska short landing competitions by about 6”. It made a difference, but at that point the difference is measured in inches, so not noticeable to most of us.
 
Witmo said:
...in this case, more is not better IMHO.
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Someone I worked with when we were fitting a tactical trainer with VGs to fix stall characteristics had a picture of the VGs on a T-39 wing with the caption "20 design mistakes you don't have to make."

They're usually there to either fix a problem that wasn't predicted during design or to make the airplane do something the designers didn't intend it to do. Neither are necessarily bad, just facts of life.

Nauga,
and the ANSER
 
At one point in my career I flew a a Citation Excel. That airplane was a hodge-podge, thrown together airplane in an attempt by Cessna to make a stand up cabin jet. It had all kinds of band-aids, including VGs.
 
You need somebody to tell you they work? Micro VGs are magic on my 180. I’ve never flown my Cub without them and I don’t intend to. I don’t care what anyone else says. They work!
 
I don’t think anyone says they don’t work, it’s the claims they don’t affect cruise speeds (probably true for slower GA planes with non laminar flow wings ) and the fact they’re ugly.
For those with laminar flow wings and low drag it has to affect your speed, maybe not significantly but does affect it, that’s just physics.
 
I fly 2 Saratoga II TCs, one with VGs and the other without. The one with VGs is lighter on the controls
 
As I get older I get fatter and my takeoff and landing numbers suffer. I should probably start adding a few VGs each year to keep my numbers in check.
 
Johnbo said:
As I get older I get fatter and my takeoff and landing numbers suffer. I should probably start adding a few VGs each year to keep my numbers in check.
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Problem is they get in the way if
you take a shower.
 
Was following a car yesterday where it looked like it had a row of VGs across the roof just above the rear window. Makes it less likely to stall on I-5, I guess....

Ron Wanttaja
 
nauga said:
Someone I worked with when we were fitting a tactical trainer with VGs to fix stall characteristics had a picture of the VGs on a T-39 wing with the caption "20 design mistakes you don't have to make."

They're usually there to either fix a problem that wasn't predicted during design or to make the airplane do something the designers didn't intend it to do. Neither are necessarily bad, just facts of life.

Nauga,
and the ANSER
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Every design is a compromise.
 
Do wings next time. I've always doubted that they work.
 
Kritchlow said:
At one point in my career I flew a a Citation Excel. That airplane was a hodge-podge, thrown together airplane in an attempt by Cessna to make a stand up cabin jet. It had all kinds of band-aids, including VGs.
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Much like the Beech 1900D just kept welding pieces of metal on until it was airworthy.
 
Does the addition of VGs have any effect on maneuvering speed?
 
The answer is Yes, obviously they work. Look at the wings and tail of any airliner or military fighter and you're going to see them. Do they work on a Cessna 172?
Well yea, sure but one of the attributes is that you can crank in full aileron at just about stall speed.
Okay but really, who does that?
Now I know that if you just spent fourteen-hundred-and-fifty dollars on a set of these you're gonna love them.
But honestly it's way harder to clean your wings with those things on there.
 
Silvaire said:
The answer is Yes, obviously they work. Look at the wings and tail of any airliner or military fighter and you're going to see them. Do they work on a Cessna 172?
Well yea, sure but one of the attributes is that you can crank in full aileron at just about stall speed.
Okay but really, who does that?
Now I know that if you just spent fourteen-hundred-and-fifty dollars on a set of these you're gonna love them.
But honestly it's way harder to clean your wings with those things on there.
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I think dirty wings make the plane faster…shark skin effect.
 
Had them on my Cherokee. Thing didn’t stall, and was always controllable in the slow flight regimen. Made a believe out of me.
 
steingar said:
Had them on my Cherokee. Thing didn’t stall, and was always controllable in the slow flight regimen. Made a believe out of me.
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Two questions if you don't mind. First, Hershey bar wing or tapered? Second, and I really mean no offense, why VG's on a Cherokee? Asking because to me the landing distance is always shorter than the takeoff distance, possibly unless there are no obstacles. Is it for safety in soft/slippery fields?
 
Albany Tom said:
Two questions if you don't mind. First, Hershey bar wing or tapered? Second, and I really mean no offense, why VG's on a Cherokee? Asking because to me the landing distance is always shorter than the takeoff distance, possibly unless there are no obstacles. Is it for safety in soft/slippery fields?
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Well if it's a Cherokee it's a Hershey bar. But I've got the Robertson STOL kit on my Cherokee 180. There was a 180 with the same kit on tap the other day. Have never seen another Cherokee with that kit. Leading edge cuffs. Fences. Longer dorsal. Vortex generators on the vertical stabilizer. I personally wouldn't have spent the money on it. But not complaining. What I've yet to figure out is if the kit hurts things on the cruise end
 
Racerx said:
Well if it's a Cherokee it's a Hershey bar. But I've got the Robertson STOL kit on my Cherokee 180. There was a 180 with the same kit on tap the other day. Have never seen another Cherokee with that kit. Leading edge cuffs. Fences. Longer dorsal. Vortex generators on the vertical stabilizer. I personally wouldn't have spent the money on it. But not complaining. What I've yet to figure out is if the kit hurts things on the cruise end
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Could have sworn they made a 150 HP tapered wing, and called it a Cherokee, but maybe it's just me being a jerk. I think of any PA-28-140-150 as a Cherokee. 180's climb pretty nice in my opinion as is, certainly much more than the 150's. A STOL kit makes more sense to me on a 180 or 235 for sure than a 150.
 
Albany Tom said:
Could have sworn they made a 150 HP tapered wing, and called it a Cherokee, but maybe it's just me being a jerk. I think of any PA-28-140-150 as a Cherokee. 180's climb pretty nice in my opinion as is, certainly much more than the 150's. A STOL kit makes more sense to me on a 180 or 235 for sure than a 150.
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Cherokee warrior had the tapered wing and a fuselage stretch in 73 or 74... pa-28-151. The second 1 denotes the tapered wing. But nobody calls it a Cherokee if they can call it a Warrior
 
Albany Tom said:
Two questions if you don't mind. First, Hershey bar wing or tapered?
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Hershey bar. It was a 1975 Pa140

Albany Tom said:
Second, and I really mean no offense, why VG's on a Cherokee? Asking because to me the landing distance is always shorter than the takeoff distance, possibly unless there are no obstacles. Is it for safety in soft/slippery fields?
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That's how it came. And yes, it could land in just about anything. Like I said, flying an airplane with them made me a believer. If your mission is to land in short little airstrips you want them.
 
Albany Tom said:
…why VG's on a Cherokee? Asking because to me the landing distance is always shorter than the takeoff distance, possibly unless there are no obstacles. Is it for safety in soft/slippery fields?
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Everybody focuses on the landing distance, but would takeoff distance not possibly be affected as well? And what about Vx climb speed/capability?
 
MauleSkinner said:
Everybody focuses on the landing distance, but would takeoff distance not possibly be affected as well? And what about Vx climb speed/capability?
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Yup, you take off in less room as well. Gotta know about Vx? No stall, short landing and short take off not good enough? Picky picky.
 
nauga said:
Yes. There, I saved you 10 minutes or so.

Nauga,
and old questions
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Yeah, I had to laugh at this thread/video.

"Here, let's see if the laws of physics have changed any in the past 50+ years on airplanes that haven't changed in the past 50+ years, either."
 
In my little Cessna 140 they get me off into Ground effect sooner, the controls feel crisper and in slow flight on the way to terra firma the controls remain crisp. It took some getting used to as control deflections needed to be much smaller. I like how it makes her handle…. And for a slow airplane not a lick of noticeable difference in speed. She did 100-110 IAS before and after…
 
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