Backcountry Pilot • another VG question

another VG question

Have you modified your aircraft? STC? STOL Kit? Major rebuild from just a data plate?
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Re: another VG question

Stickman wrote:Many years ago I flew Linn Emrichs' Mighty Mouse. It was a very modified C-150, it had extended flaps and an articulated elevator.For a while it had speed brakes! :shock: Oh, it also had an O-360 in it. With the extended flaps it was very nose down on final.
The airplane is still around, it may be at Steve Knopps on Camano Island.
May give you some ideas anyway.


Mighty Mouse was parked at camano until fairly recently, a supercub guy who tows banners out of Snohomish (can't recall his name) bought it & took it away earlier this year.
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Re: another VG question

Throttle Pusher wrote:You cant see over the nose when landing in a C150? :shock:
I'd say he does need a pillow to sit on.


Seeing as I only stand 5-5, I could take offense at that crack and tell you what you can go sit on but I won't. [-X BTW it might be harder to see out of a C150 than you think-- it's got way less forward-and-down viz than my old C170 did.
Keith, I don't have to do such a radical nose-high landing to get in short, I've just been experimenting with different techniques. My C150/150 does pretty good on takeoff with a 56 pitch prop, but I'm planning on adding VG's & flattening the prop a couple inches this winter to make it do even better. Still won't be any competition for a supercub with a borer, but oughta do pretty good.
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Re: another VG question

I'm not into insulting height-challenged folk, but the cushion idea has lots of merit. When I was learning in 150s back in 1972, my instructor was similarly height-challenged. Early on, he kept saying "raise the nose so that it hides the end of the runway." When I'd try that, I'd nearly stall it way too early. He was about 5'6" and I was just under 5'11" with relatively short legs and a long torso, so that I sit more like someone who is over 6' tall (shrunk a little since then :)) It dawned on me that what he was saying to look for, I wasn't seeing, solely because of the difference in our heights. So I memorized what I was seeing when he said he was covering the end of the runway with the nose. When I was instructing later, I told my students to raise the nose to the same angle that they used for a normal take-off, and that took care of any height differences.

For myself, I don't like coming in at a high AOA hanging on the prop--too easy for a hiccup that puts you into the trees. I can pretty easily get my 172 down and stopped without sliding the tires in 500', so it's just not necessary to do it your way--unless you're really into extraordinarily short strips.

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Re: another VG question

Cary wrote:............For myself, I don't like coming in at a high AOA hanging on the prop--too easy for a hiccup that puts you into the trees. I can pretty easily get my 172 down and stopped without sliding the tires in 500', so it's just not necessary to do it your way--unless you're really into extraordinarily short strips.


I'm not talking about a long flat hanging-on-the-prop approach, I'm talking about a steep slow approach- the high AOA is to keep the forward speed down, with power added as required to moderate the sink rate. If anything, this approach has me higher than a standard type of approach. If the engine sputters, I can push the nose down for more airspeed which flattens out the glide to where I have no trouble reaching the runway. I use the same nose-up attitude when I'm too high on an approach, to achieve a high sink rate. Some people refer to this as "stalling it down", although you're not really stalling the airplane.
If I do this right, I can come over the numbers ready to land with the ASI reading about 40 mph-- not accurate in that low range, but definitely slower than the "standard" approach made at 60-65 IAS..
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Re: another VG question

I added MicroAeroDynamics VGs to my 1986 Maule MX-7-180 in 2010 after flying it without them for 12 years. They make my landings easier since the wing doesn't stall abruptly now. They prevent the sudden onset of a stall on top of the wings and under the horizontal stabilizer. I haven't noticed any decrease in cruise speed but my 8.50 tires and Alaskan Bushwheels HD gear legs are pretty draggy so any drag from the VGs is not noticeable. I'm more interested in fuel economy at today's fuel prices than an extra few knots of airspeed at higher power settings. If you feel the same way, don't worry about drag from the VGs. People say that they notice better slow airspeed handling with the VGs but I can't honestly say that I've noticed a big difference in the controls except for the better stall performance. The VGs not only delay the onset of a stall at slow airspeeds but they lower the stall speed about 3% with 48 degrees of flaps and 14% with no flaps. I've noticed that.

From a final approach perspective, I now feel more comfortable approaching at lower airspeeds for shorter landings. I don't usually come in nose high until the flare since there's no need to do that with the slower airspeed. I still manage airspeed primarily with pitch and descent rate with power. The VGs don't really change that.

One thing I would definitely recommend is that you apply the VGs to the bare material of the wing rather than a painted surface. They adhere much better and you won't have to worry about knocking them off when you use wing covers.
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Re: another VG question

High sink rate, slow and low. No thanks.
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Re: another VG question

I'm surprised that your high sink rate, very slow airspeed method doesn't result in a really hard landing when you flare, coupled with a complete loss of elevator control so that the nose plops down hard right after the mains. Aerodynamically speaking, your method is coming very close to the maximum angle of attack immediately pre-stall, which means that as soon as you flare, you're likely exceeding that maximum AOA, so that the whole wing stalls, not just the inboard part. I also tend to think that once you're pretty close to the ground, any hiccup couldn't be countered with dropping the nose--more likely you'd immediately stall and hit before reaching the runway. It might work if the hiccup occurred while still 350' to 400' above the ground, but not a lot lower.

Don't get me wrong. I believe in relatively slow approaches, 1.3 Vso on approach, 1.2 Vso over the fence, etc., not the high end of the range in typical newer POHs. But I think you've cut your safety margins so slim that your method is too slow and not safe.

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Re: another VG question

Cary wrote:I'm surprised that your high sink rate, very slow airspeed method doesn't result in a really hard landing when you flare,
Cary
Go try some departure stalls and some power off stalls at altitude. See what it tells you about AOA. Then factor in ground effect with power added. Apples and oranges.
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