Ok Gunny you got the airplane.

I made one power off landing in a Skywagon in 20 years of flying them so am not an expert in that configuration. Check pilot pulled the power at about 100' while taking off on floats. Nose down, glide a bit to maintain and maybe gain some energy then flaps full just prior to touchdown followed by a flare. Sure can't tell what's happening to you from that brief experience.

But just for another skill set try the low but not landing approach someday and see what happens.

Gary

Perhaps you should chalk it up to your low time ans inexperience Gunny?

LOL

Gunny wrote:.... In most other airplanes I prefer a power off approach all the way to touchdown. I find it doesn't work really well with the Skywagon (unless you are fast, which poses its own problems)... so I use trailing throttle. Just enough to provide wash over the horizontal and give me authority......I haven't tested techniques for actual distance, but my speculation is that with trailing throttle the distance would be greater. But if done on pavement the power-off technique does end up costing distance as you bounce quite a bit;) Common sense says just use the trailing throttle....

I don't have any ideas why your tail drops as you describe.
As far as power on or off landings....
my experience with other airplanes is like yours, preferably I liked power-off.
With the 180, not so much.
Mine has a bone-stock wing, and stalls power-off and dirty at somewhere around 43 indicated.
1.2x that would be between 50 & 55, works good for a slow approach to a 3-point landing, but there's a huge sink rate if done with no power.
Keeping a little power on, adjusting as necessary to moderate sink rate, works much better.
I use 65-ish for an approach to a wheel landing, again carrying a bit of power.
I tend to wheel land on pavement and 3-point onto grass.

Well, as I noted in another thread I put WingX extensions on the airplane. I tufted the wing and the horizontal to test my theories. I really need to do another flight or two with the tufts to get good results, but I haven't been able to duplicate the same nose drop when I hit ground effect with the power off. When I feel good about the results I'll post the video.

If this lack of nose drop holds with the WingX then perhaps its a downwash issue from the wing hitting ground effect in the sportsman config. To be honest I'm not going to take the WingX off to go back and get confirmation data. My curiosity factor doesn't overcome the hassle factor. At least not now. I would expect it to go away completely with Vgs installed.

Aerodynamics is an amazing thing.

gunny

Gunny wrote:Well, as I noted in another thread I put WingX extensions on the airplane. I tufted the wing and the horizontal to test my theories. I really need to do another flight or two with the tufts to get good results, but I haven't been able to duplicate the same nose drop when I hit ground effect with the power off. When I feel good about the results I'll post the video.

If this lack of nose drop holds with the WingX then perhaps its a downwash issue from the wing hitting ground effect in the sportsman config. To be honest I'm not going to take the WingX off to go back and get confirmation data. My curiosity factor doesn't overcome the hassle factor. At least not now. I would expect it to go away completely with Vgs installed.

Aerodynamics is an amazing thing.

gunny

Thanks for the follow-up!

Sent from my SAMSUNG-SM-G890A using Tapatalk

Would dialing in full nose down trim increase up elevator authority you can then use to muscle up the nose? That works with trim tabs. Not sure about trimable stabilizers, though. Just a thought.

CAVU

CAVU wrote:Would dialing in full nose down trim increase up elevator authority you can then use to muscle up the nose? That works with trim tabs. Not sure about trimable stabilizers, though. Just a thought.

CAVU

No, don’t think so.

CAVU wrote:Would dialing in full nose down trim increase up elevator authority you can then use to muscle up the nose? That works with trim tabs. Not sure about trimable stabilizers, though. Just a thought.

CAVU

No. With a trimable stab like Skywagons and Cubs, if you don't have it trimmed for you flight conditions you have less control authority. That is one of the reasons most people praise the trim system in the Skywagon over the 182, which has trim tabs: it retains more control authority at slow flight. If i'm light and don't have my toolkit or some other ballast in my extended baggage area I will run out of nose up trim when landing. The result is I have limited pitch authority and I can easily get to full deflection on the elevator before achieving the desired (or needed) pitch rate. The aircraft becomes both pitch and pitch rate limited since like Gunny described, I can't get the wing to break in this condition; the plane just mushes down at 700 fpm with the nose pointed up and the yolk full up. This limits how aggressive I can be with the flare in this lightly loaded condition. When clearing an obstacle I can land shorter with an extra 50 lbs or so in the back than I can at min weight since that allows me to trim the aircraft for approach speed and I can arrest my sink rate more aggressively. For shallow approaches, this generally is not a limiting characteristic for me. It's impressive how much bounce the Cessna gear can absorb when I screw this up, though.

Interesting. Thanks.

CAVU

And... With a fixed horizontal stab like on a C172 or newer C182, that trim tab acts like a flap on the elevator.

Rolling trim tab full nose DOWN raises the tab up, so you then have a mini-flap extended when hauling back on the elevator. Not much flap surface, but a little, and it does make a difference.

Trimmable tail is a whole lot more effective.

Gump

Fredy-

Excellent comments, thanks!

gunny

Indeed, trimmable stabilizers are much more efficient in several regards....including cruise speed....

That said, I often run in just a bit of nose DOWN trim just prior to touch. Two reasons:

1. That little bit of nose down trim makes a go around much easier and smoother, with full flaps deployed.

2. It also makes “sticking” a wheel landing much easier, particularly for someone with low 180/185 experience.

Carrying a bit of power into the touch is basically a given in these airplanes in my experience. I can certainly land one without power, but it’ll never be as nice.

I seriously doubt that wee bit of power on approach increases touchdown speed at all, done right. In fact, if anything, a wee bit of thrust keeps the flow organized over the tail, and inboard section of the wings.

Clarification: The vast majority of my experience with these airplanes was with Robertson STOL equipped examples. Advertised (and in my experience) stall speed in these airplanes - 37 knots.

MTV

MTV-

I've been thinking about this again as I finished up my video of the Stall Testing (posted on the Wing Performance Thread). I realized that the Tufting showed there is quite a bit of airflow over the wing from the prop alone. With a little power you get pitch authority from airflow over the tail... and you get a little more lift from the wing as well ( a phenomenon seen on high wing, wing mounted engined airplanes like the YC-14).

Since my previous theory didn't work ( I should have done the tuft testing before putting WingX on to validate it), my new theory is that when the wing hits ground effect without that extra powered lift there is a net decrease in lift.... thus the nose drop. I think this is consistent with the result of adding the WingX Extensions... there is still a measure of reserve lift in the wing from the extra wing area.... in that the nose drop is not as pronounced.

I still find the airplane prefers a little power in the landing phase. Still learning.

gunny

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