Slip Speeds

[JoeRuscito]

Thanks for that Dave. It's helpful to understand the margin you are using above stall. If I understand correctly when you are over the numbers you are hovering about 5-8 mph above your stall. As I currently come over the numbers Im carrying about 10-12 mph above stall and likely why Im not sinking and floating. Agreed I don't want to get anywhere near 1 mph above with any height under me, and really thats why I started the post to gauge where everyone is at compared to my practice.

[Dave S]

Joe,

In my response, I intentionally used 1.3 times Vs/Vso & minus 5 rather than my ASI indications because each of our airplanes is likely to have airspeed indicators that read a little different - and V speeds change with loading also.

Actually it works out to 10 MPH above stall in my case over the numbers; and, the procedures I indicated are out the window if conditions are windy/turbulent at all - I consider this is only for short field/obstacle precision work under ideal wind conditions.

In my early flights with our kitfox, I stayed with Vs/Vso + 5mph for final down to 10 feet above the runway then bled off the speed gradually - still landed way shorter than any aircraft I had ever flown before so it was a new era anyway.

For normal landings I currently stick with 1.3 times Vs/Vso on final down to the threshold.

FWIW - once I adjusted the idle speed - that made a noticeable difference with the same airspeeds.

[kitfoxnick]

I’ve been gone a long while but this seams as good a place to step in as any. Get VGs! At my strip 900’ with trees 400’ from the threshold. My preference is to come in over the trees with a lot of flaps and a full slip to ground effect. Pop it out and almost three point it. Dump the flaps full brakes and stick forward. When the tail starts to feel light you can let it down. Never once do you get a chance to look at airspeed. My advice is to go slip your plane in landing configuration keep slowing down listening and feeling what your plane is saying. In a slip mine starts a little hum then a slight high vibration feeling right before it breaks. A little stick forward and it goes away. Practice falling leaf. Cover your airspeed up for a month. Best thing I did was fly whole summer with an airspeed indicator covered. The absolute shortest landing with out an obstacle is to enter a wings almost level mush and arrest your decent (flair) with the engine. Hopes this helps.

[redbowen]

Dave said a lot of what I am thinking on this issue. 1.3 Vs0 is a slow as you should make your approaches safely. I suggest going up to altitude and set up the same configuration you have as you come over your obstacle, and get slow enough to stall it, many times until you can recognize the onset signs. Without VG’s you will get more notification buffeting. Note your attitude and indicated airspeed, cross check with ground speed by doing it in multiple directions. I recommend this because in a slip your airspeed indicator is unreliable so if you pay attention to your airspeed vs ground speed on approach you can determine your winds to some degree and then you can cross check your speeds. Now I am not going to tell you that I don’t go below 1.3, because I do, but I usually do it at the very end of the approach. I use 50 mph down to just shy of the flare. That gives you the energy to flare to stall without adding power, but you can flare to 45 add power and get a bit slower as you do a full stall landing. With my so called heavy Lycoming Kitfox 5 that will give me a consistent 200’ landing with no wind. Add some wind and it gets nice and short. The best thing you can do is every time you fly go up to altitude and do some stalls in landing configuration. Stall numbers one day will vary from another based on density altitude and aircraft loading, winds, turbulence, etc. So the more you practice the stalls the better you get at recognizing the onset and learn how to avoid pushing past that point.
Great question. Fly safe, practice often.


Project Kitfox

[fastfred]

Hey Bryan

Project Kitfox[/ Maybe we should clarify where to use the 1.3 figure? Where does the approach start? Some guys tell me get down to approach speed turning a base others define approach as the final or short final. Personally I don't like to turn to final at 55 or even 60 as the kitfox slows down very quickly. I would also slip at a higher speed for this same reason. 50 or below on final is out of my comfort level until I am into the flare. I don't plan on winning any STOL competitions either.
Anyway when on approach do you get to that 1.3 or below?

[Rodney]

Joe - If your thinking of putting VG's on - Alex Di Sessi has an excellent youtube video on the subject of VG's.

He presents some pretty convincing information regarding placement of the VG's. You might find it interesting.

Regards
Rodney

[fastfred]

Personally I rarely seem to need a slip. Like S and R taught us fly the fox down to the approach as slow as you can then ease back on the stick to slow down to stall on the numbers . I usually don't below 60.

[Shadowrider]

Joe I have found that VG'S help a ton, but can make it worse if you don't fly slower, as far as landing distance goes.

[redbowen]

This is very true with the VG’s, they absolutely work and lower your stall speeds but they also remove the onset signs. It was one of the first things I noticed about the VG’s, Stalls slower with little warning.




Project Kitfox

[n85ae]

Take it up to altitude and try. I have slowed mine down and slipped all the way until it stops flying. I get
a really hard buffeting rattle in the turtledeck right before stall, and if you're trimmed to require holding
some back pressure it flies right out of it with relaxing the controls.

I kick in slip very frequently for glidepath control, even on very short final. I think it's a natural thing
in these airplanes to use.

I can't speak for other people's planes, but mine gives plenty of warning when it is unhappy while slow
and cross controlled.

Actually my airplane unless you pull the nose up hard with power and intentionally stall it with a lot of
attitude, never does anything very surprising.

The only time my airplane misbehaved is with 22 degrees flaperons, and since then I mechanically
blocked the slot for maximum 11 degrees.

Jeff