New Kitfox 5 Tailwheel owner - landing problem

[Rolfer]

Hi,

My grass strip is 1200’ long. With airspeed of 55 mph on final approach and full flapperon, I’m find that she floats and floats. Sometimes I have to abort landing due to the floating. I had no similar problems with my Aeronca Chief.

Does anyone have suggestions?

Thanks

[avidflyer]

Is your ASI acurate? Maybe it reads slow and you are actually going a bit faster. What speed does it show at stall with power off? You can test an ASI with a manometer. For a certain number of inches of water column, the ASI should read a certain number. The chart in the link gives speeds and manometer reading you should have at those speeds. When I did the test, I blocked off the end of the tube, and then kept folding it up in my hand which increased the pressure to whatever reading I was looking for. Pressure is very small. Don't even think about blowing into it. JImChuk

www.n56ml.com/airspeed_calibration/ (http://www.n56ml.com/airspeed_calibration/)

[Kitfox Guy]

A handheld GPS (or any GPS for that matter) will give you an idea if your instruments are accurate.

[jiott]

try using 1/2 flaps to reduce float.

[Dusty]

If you are floating you are too fast. As suggested check your airspeed indicator,or better still ignore it and fly the last bit of your approach by angle of attack and sink rate. The final flare should use the wings last remaining lift ensuring no chance of a bounce which will use precious runway length.

[airlina]

To find a good over the fence speed, I would suggest you do some work at altitude to come up with a good number. At a safe altitude do some stalls with 1/2 flaps (11 degrees or first notch in the Series 5) and note the airspeed. For certified airplanes they typically use 1.3 Vso for a final approach speed , but I have found that in my Series 5 that number would produce the float you speak of. I use 1.2 Vso (or 1.2 times the stall speed you saw at altitude.) This will eliminate the float if you cross the fence at this number , but be advised it does not leave you much room for error and PRECISE speed control is mandatory. Also if its windy or gusty you need to bump the number up . Also as Jim mentioned previously stick with 1/2 flaps as some control harmony is lost with full flaps. Bruce N199CL

[Esser]

My ASI isn't accurate down low. It reads high but for rough numbers, my plane doesn't sink on approach until I get below 50kts. I then approach at 45, roll it over the fence with a touch of power and land at 38. If I go any faster she will not land.

[Rolfer]

My ASI reads 46 mph at stall with power off and one notch of flaps. I will take a GPS with me on next flight to see if ASI is accurate. What descent rate do you typically aim for on final?
Thanks for all your suggestions, guys.

[David47]

Thanks for posting that link Jim. Very useful. And I agree with Dusty, sounds like you're too fast for the flap setting you have.

[n85ae]

My Series 5 (w/IO-240B) took a long time to learn to land. It's a speed issue really, any speed that "feels"
comfortable will result in float. If you're slow enough to land short, it's mushy, and sinky feeling, and does
not feel comfortable ...

The one good thing is that the airplane is pretty predictable when feeling mushy, and sinky, so you can fly
it by seat of pants feel pretty well

Experience and practice are the key, and for sure if it's floating it's going too fast.

Also in my opinion the only thing the flaperons do for landing is change the pitch attitude, they really don't
influence the float issue that much ...

Jeff

[Rolfer]

Thanks for your comments Jeff. Do you use one notch or full flap on final?
Rolfer

[Maverick]

From what I remember from learning to fly was to fly the airplane, not the instruments. Obviously ASI calibration is truly important but, doing take off and landings will familiarize yourself with the characteristics of the plane. Glancing at the ASI is necessary but once you are committed, you don't look at the ASI, you fly the plane right down to the ground. I used to land anywhere and everywhere I could, fields in the Texas Panhandle, flat places in the Arizona desert, dirt, grass, gravel, paved runways, high altitude and low altitude strips, etc. over and over and over to the point that the feel of the plane determined approach speeds. I practiced with 2 passengers as well as weight in the baggage compartment, alone, half fuel, full fuel, etc. It was amazing what you can make a Kitfox do. While instruments are important, before all the electronic wizardry came along, people were taught to know the airplane from the seat of your pants. Practice, practice, practice. . .

[Slyfox]

absolutely.
now days you have all these aids for flying, landing. me I just set up for 50 over the numbers and never look at the asi again. I try to 3 point for short landing. with that said as I'm getting close to landing I'll pull back on the stick slightly, if it wants to go back up I'm not slow enough. should be able to pull back and the tail go down, go full back and yes land on the tail first than the main come down for a nice smooth landing. I personally don't use flaps, my fox will slow real nice and I can land and be turning 180 within 300ft most times way shorter than that. why no flaps. I don't know, maybe because it's too much of a reach for my short arms. maybe some day I'll put an extension on it. don't know. I also don't like the nose being forced down and tail won't come down with them on. I do know I can major slip my bird right from the midfield and just relax the rudder for my turns, way fun. with my prop set for flat and can slow down real good. just me I guess, but I fly seat of the pants all the time. just glance on short final for my speeds. my suggestion is to go up to altitude and find when your plane stalls and use that plus 15 for final. go to about 5+ for over the numbers. the asi might be wrong.

[Rolfer]

Thanks for your excellent advice guys......much appreciated!

[n85ae]

Here's my opinionated comments:

My airplane I feel that full flaperons is not safe, so I mechanically limited the flaperons for one
notch max, AND I removed the trim assist spring I had also. I feel the two of them combined
to create what I believe is a tailplane stall. There's a thread on the forum about it if you search
on trim assist spring I believe.

I make pretty much every landing with a notch of flaperons, and I 3-pt land always. I'm in the
school of thought that wheel landings are actually two landings, so I just like to put everything
down at once.

I also experimented quite a bit with AOA systems, and in the end I don't use them in my airplane.
The airplane tells you what it's doing.

If it's a breezy day, I tend to fly most of base and final at 60'ish. If it's calm, and feels safe I often
fly final at around 45 and short final on the edge of needing power. When I first started flying the
airplane I was typically much faster, and experienced a lot of floating like you are. For a while I
solved this with wheel landings and just planted it, and used the brakes.

On a normal day I get a little past runway end on downwind, pull power back to about 1500 rpm,
slow it to below 80, pull in 1 notch of flaperons, and adjust descent for about 500 fpm, and 60 mph.
Then as I get on final I decide whether to slip, or just power back and slow down more.

Jeff

[Rolfer]

Jeff, thanks for your detailed reply. On a calm day I was flying 55 on short final and this appears to be too fast for my 1200’ strip. I’ll be using yours and other guys recommendations in the future.
Cheers, Rolfer.

[Av8r3400]

My plane is a model IV, so it is a little lighter therefore lands a little slower. Here is a video of several landings on my 900' strip. The speeds I call out are all in MPH and are indicated. Accuracy at that slow speed is not great.


https://youtu.be/xoLbVFPlwFQ

[Rolfer]

Thanks for sharing your video. Getting in and out of your 900’ strip with tall trees each end must be a real challenge. My 1200’ strip with no obstructions looks easy by comparison.

[Bartman1959]

I recommend going out somewhere where you have no pressure for a make or break landing, and practice spot landings for a few hours.

[Rolfer]

Yes practice, practice is the key. This is what I’ve been doing in the last few days and now I’m landing on my short trip without excessive float. Thanks guys, for all your good advice.
Rolfer

[GuppyWN]

What does the airplane stall at with no, one and two notches of flaps?

[Rolfer]

What does the airplane stall at with no, one and two notches of flaps?

My Kitfox Series 5 shows the following ASI stall speed readings with power off and weight of 1250 lbs:

No flaps 48 mph
One notch 46 mph
Full flap 44 mph

I find that there is no abrupt stall. It just mushes. I found no tendency to drop a wing. The nose is held high at the stall.

[PapuaPilot]

My Kitfox Series 5 shows the following ASI stall speed readings with power off and weight of 1250 lbs:

No flaps 48 mph
One notch 46 mph
Full flap 44 mph

My model 5 stalls at 49, 46 and 43 MIAS at 1250#. It's good to see how they are similar.