I can make a slow steep approach, keeping the nose up for low airspeed (45-50 IAS) and moderating the (high) sink rate with power as required. This makes for a nice short landing but also makes for poor visibilty in front of me. I am wondering if a set of Micro VG's would tend to allow a lower deck angle for a given speed, or vice versa, or make little to no difference at all. FWIW this is with a stock C150 wing.
I don't wanna pony up the $2K for a Sportsman cuff plus a bunch more for the install, so let's not even go there. And no, I don't wanna "just buy a Maule".

Answer to your question... Nope. VG's will not lower your deck angle. VG's allow you to have a higher deck angle without flow separation on the upper surface of the wing ie: stall.

G44

hotrod150 wrote:I can make a slow steep approach, keeping the nose up for low airspeed (45-50 IAS) and moderating the (high) sink rate with power as required. This makes for a nice short landing but also makes for poor visibilty in front of me. I am wondering if a set of Micro VG's would tend to allow a lower deck angle for a given speed, or vice versa, or make little to no difference at all. FWIW this is with a stock C150 wing.
I don't wanna pony up the $2K for a Sportsman cuff plus a bunch more for the install, so let's not even go there. And no, I don't wanna "just buy a Maule".

How much flaps you got on when you are doin this?

Everything I got-- 40 degrees.I think less flaps would require a higher deck angle to achieve the same AOA.

If you want a lower deck angle and you already have 40 degrees of flap, your best option from an AERODYNAMIC point of view is drooping the ailerons too, which was done on the Robertson STOL mods in the '70s. This gives you the nose down at low speeds you want... but it also creates an additional set of problems you would have to address, such as changing the mounting angle of the stabilizer (decalage), and/or increasing the elevator authority somehow. From a regulatory and legality standpoint, of course, you'd be way off the end of the chart into crazy-land.

You can also adjust the decalage SLIGHTLY by making sure the eccentric bushings in the rear spar attach are in the down position, but you're only getting a degree or so which may not be enough.

IMHO the really clever way to address this with far less legal/insurance and FAA headaches is making it so you can see where you're going with the airplane doing what it already wants to do. A small nose mounted camera putting a real-time signal onto an iPad or small media player screen on the panel will allow you to sidestep the problem without redesigning the whole airplane. You can probably get a cheap automotive back-up camera system at an automotive store and adapt it for this purpose pretty cheap.

Or, if there is a big bubble window available for the 150, where you could lean over and see downward... this might allow you to fly a slightly curved approach and keep your eyes on your LZ until the last couple of seconds.

Another thing I do when flying b/c is move any extra wt, tools/surval stuff, as far forward as practical, making it easier for the tail up/nose low attitude on approach(as you already know, the180 has a trimmable tail which is a huge help here), and lets me get tail up sooner=shorter t/o, and minimizing damage to the tail.
Gary

Sit on a pillow.

shortfielder wrote:Another thing I do when flying b/c is move any extra wt, tools/surval stuff, as far forward as practical, making it easier for the tail up/nose low attitude on approach(as you already know, the180 has a trimmable tail which is a huge help here), and lets me get tail up sooner=shorter t/o, and minimizing damage to the tail.
Gary

My extended baggage has 70 lbs. of "Stuff" and helps a lot keeping tail pushed down. Heard (?) from 180 driver that VG's on bottom of Horizontal stab will improve low speed hand landing. He didn't do wing just tail. I may try the tail VG mod myself ??? I have Sportsman STOL leading edge that does alot better than anything else.

182 STOL driver wrote:

shortfielder wrote:Another thing I do when flying b/c is move any extra wt, tools/surval stuff, as far forward as practical, making it easier for the tail up/nose low attitude on approach(as you already know, the180 has a trimmable tail which is a huge help here), and lets me get tail up sooner=shorter t/o, and minimizing damage to the tail.
Gary

My extended baggage has 70 lbs. of "Stuff" and helps a lot keeping tail pushed down. Heard (?) from 180 driver that VG's on bottom of Horizontal stab will improve low speed hand landing. He didn't do wing just tail. I may try the tail VG mod myself ??? I have Sportsman STOL leading edge that does alot better than anything else.

Get both tail and wing vg's........they compliment each other, you can't get the most out of each without having both.

Good morning Bill
If I am doing a longer cross country I put the wt. to the rear so I use less trim/drag to stay in trim and gain a littl speed. As I said, for backcountry/short field stuff I like having the wt. forward so the tail gets up soner. With your 182, that's not an issue, cuz your tail is already up. Which, I feel, ispart of why 182's get off quicker than 180's
I have the Sportsman kit and the Micro vg's on the wing and tail.
Gary

shortfielder wrote:Good morning Bill
If I am doing a longer cross country I put the wt. to the rear so I use less trim/drag to stay in trim and gain a littl speed. As I said, for backcountry/short field stuff I like having the wt. forward so the tail gets up soner. With your 182, that's not an issue, cuz your tail is already up. Which, I feel, ispart of why 182's get off quicker than 180's
I have the Sportsman kit and the Micro vg's on the wing and tail.
Gary

Gary & Flight >
I'll just have the SPORTSMAN on wing leading edge ----NO VG's There for me. The horizontal is a different story -maybe ?? I don't run out of rudder or elevator even with indicated air speeds of 50 mph or less . I'm building a "monster 470" this winter to take takeoffs to a whole next level .I've got the IO-520 (that could be built up as a 550 ) but I trying to avoid putting it on my 182 . I'd like to sell or trade the IO-520 ,It would be a good start for a Pponk.

Jumpy wrote:Sit on a pillow.

You ever been in a Cessna 150?

shortfielder wrote:Good morning Bill
If I am doing a longer cross country I put the wt. to the rear so I use less trim/drag to stay in trim and gain a littl speed. As I said, for backcountry/short field stuff I like having the wt. forward so the tail gets up soner. With your 182, that's not an issue, cuz your tail is already up. Which, I feel, ispart of why 182's get off quicker than 180's
I have the Sportsman kit and the Micro vg's on the wing and tail.
Gary

Forward C/G = higher stall speed.....

MTV

Learn to land blind. Every pilot who flies bi-planes sits in the back seat and can't see. Anyone who does tailwheel instruction in a tandem aircraft lands without seeing the runway. Hell, anyone who solos a J-3 Cub lands without runway visibility. Use a slip on short final to take a last look at the runway, then use peripheral vision to land.

I'll be diplomatic & say thanks for the suggestions-- only one response addressed my question though.
Drooping ailerons a la Robertson STOL don't seem like the greatest idea-- the biggest problem is probably the decrease in aileron authority, due to limited amount of down aileron with them already down a ways with the droop feature. I think a better mod for my purposes would be to increase the flap travel to 50 degrees or so. Easier to engineer but probably a hassle to get approval for.
Flap, I can't tell if you're serious with the camera/ipod comment or just pulling my leg. Since that sort of thing is definitely NOT where my head is at, I'll just say "good one!" and give you a

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

hotrod150 wrote: Flap, I can't tell if you're serious with the camera/ipod comment or just pulling my leg. Since that sort of thing is definitely NOT where my head is at, I'll just say "good one!" and give you a

Believe it or not I wasn't pulling your leg, I was serious about the auto backup camera. Not that it wasn't a funky and odd-ball idea (it is), but it's the only thing that could possibly help some without doing major surgery to the airplane. All your other options are significant redesigns. I'll assume the "pillow" idea has either already been done and you have reached your headroom limit.

I'm sure that the problems drooping ailerons are accurate... decreased down aileron etc. is probably correct. But since you would be redesigning the control system to do any of this, you can compensate for that aileron issue by increasing the upward travel (which would be moving in the right direction for proverse yaw instead of adverse yaw. This means different bellcranks and geometry of course.

On the model gliders and some of the better full scale sailplanes, they use a configuration called the "crow" position. Flaps down 40, ailerons up 10 or 15. That gives you three benefits... 1) Unloads the wingtips so you can maneuver safely with large control inputs at low speed, with far less tendency to tip stall/ incipient spin. 2) Also solves the adverse yaw issue as mentioned above. 3) Also adds more drag... which means you will have to keep a much more nose-down deck angle for the same approach airspeed... which would solve your visibility problem. Make no mistake, this is a very very complex project and you will be redesigning the entire wing control system... but this would definitely solve your visibility issue from the complete opposite direction as you would think. If you want to see this actually work with your own eyes, find someone who flies the AS-W20 sailplane and ask them to demonstrate a steep approach with full flap deployment (and no spoilers which would only confuse and obscure the demonstration). As I have gleefully mentioned on this forum already, the '20 can descend at an alarmingly steep angle at slow speed for a world class spot landing using this flaps down/ailerons up system. But again this is a complete redesign of the 150's flap/aileron system. Rotsa Ruck with the FSDO...

Going to 50 degrees of flap sounds kinda iffy to me FWIW. You could easily run out of elevator power to flare, and/or "blank out" the tail with that much flap if you're not careful. I know the early Bird Dog had 60 degree flaps, but they also reduced that after several accidents.

Here's another idea... the Wayne Mackey STOL-Quest approach. Make a smaller or more steeply sloped cowling if there is room. The air intakes on a 150 cowl are far bigger than they need to be in all likelihood (it's the air exit that limits the cooling flow of course). So if you can make a lower profile top/front cowling you may get another 6 or 8 degrees of downward visibility. That may be worthwhile, since it isn't major surgery.

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! 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.

hotrod150,
I appologize now for getting this off topic, having owned a 150 and a 172 I am a little lost at why you need to be at such a high angle to land. Sure I can plop my 172 down into a very tight place by doing what you are doing but there is no way in hell I would ever get out of a place so tight I need to use that technique. Does the 150 HP 150 have that much better T/O performance? I don't mean this as an insult, I am truly interested as I haven't seen a 150/172 that can get out of an an area as short as it can land in, in stock configuration.
A friend has a 150 HP (or 160) 150 Cessna and it is a speed demon but not a STOL plane by any means. I believe he has a 'cruise' pitched prop on it.
Keith

Yes, a 150/150 with a climb prop can get out that quick! We have a few guys around the local airports that fly them. Pretty damn impressive for a spam can!