Full Flap Use

[Av8r3400]

My IV is rigged for 26 degrees at full flap. I don't use that all the time, but occasionally when I want to land real short...

I've never had any issue with inversion or flapperon stall. This is the first time I've ever heard of tail plane stall on this design. Having a forward cg as a factor makes sense, though.

[Slyfox]

now for me to comment more. I hate the flaps. for one it's just to much work to reach down and pull on the lever. it lowers the front. I don't feel the flaps do much for lowering the stall.

with that said. how do I fly my airplane. like a crazy man of course. I can do a base to final right over the numbers and still stop the plane within 300ft. how do I do that.

well, how about, and I have said this here many a times, I have the idle @ about 500 or less if I pull the throttle all the way out, sometimes I have landed with the engine off. OHG no way, yes way. if I want to land short, usually to show off to someone waiting to take off. I will do this.

I have a medium Ivo prop. this prop is set up with no extra washers. meaning I can flatten it where I want and course it where I want. the course part only will be set to 5200 rpm generally. flatten, depends on how direct I want to point the nose. I can be in real short @ 800ft and slow to 50mph and drop, literally drop out of the sky with throttle pulled all the way back. I will generally hang at 90mph. I will slip with full rudder and quit a bit of aileron all the way to the final, which can be really short. once I line up I keep the rudder in and level the wings. very quickly the airspeed will go away and than I let go of the rudder and land.

Now two other things my airplane has, electric trim in the elevator, very much like this. the other is vgs. I love those also. there are many benefits of those and I just don't want to get in to that at this time.

flaps quit honestly I just flat out don't use. On take off the other day on asphalt I hit the power, pushed the stick forward and it was off the ground as fast as I hit the throttle. why would you need more than that?

[Dorsal]

2 more cents
On landing I use one notch regularly (it lowers my stall speed ~3-4 mph), I have the spring assist which I like and electric trim which I also like. One notch of flap and full trim floats my ship in very nicely on final pretty much hands off. I do enjoy steep slips also (except when the tanks are full ) and practice them for fun. I don't use full flaps as I find it makes the ship mushy and doesn't seem to add much.

[Dave S]

Have to second Dorsal's ....regarding steep slips and full tanks......I also found out that it is entirely possible to get a trace of gas fumes in the cockpit with a max slip & full rudder.......at first I couldn't figure out where the stink was coming from........then, after doing the slips, I noticed a little drool mark from the fuel cap pitot across the wing pointing straight at the little slot on the tail access cover where the vapors could be vacuumed back up into the fusdelage....yeah....there were fuel spots & drool on the tail access cover too.....maybe I only noticed it that day because I hadn't washed the plane (double) and there was enough dirt and bird gunk to dissolve in the gasoline drops and leave a noticeable trail......oh well....

Dave S
KF7 Trigear

[beeryboats]

I just had to jump in here even though I have yet to fly my new to me mod IV. I learned to fly in a Piper Vagabond that is almost the same specs as the Kitfox, but with no flaps. Same weight, wingspan, 65hp, etc and all aileron. It would slip like a demon! Except for takeoff, I see no reason for flaps if you know how to slip. Start slow and learn how she reacts to rudder and opposite aileron and enjoy the ride down. I was amazed how you can go from a minor correction on final to a total elevator ride with just a little cross controlling.
Jay

[N981MS]

As a data point.

S6-TD-IO240

I am not suggesting that my way is correct or better. But these have been my experiences.

I have used full flaps for 10 years (700 hrs) on most of my landings. I don't pull any flaps until on final. I do not have the trim assist. I have never had a problem and I suppose that I am so used to the adverse yaw that I don't notice any more.

Power off stalls with full flaps and full aft stick have consistently resulted in a nose slightly high descent with continuous very mushy aileron control. Plenty good enough to keep wings level.

I do not doubt what happened to Jeff and it does give me a bit of concern. But something different than my typical approach (right or wrong) obviously happened to him.

Half flap stall and full flap stalls are about 5 kts slower than clean.

I plan to go out and do some performance approaches with all 3 configurations to get an idea of actual short field best practice.

I love slips but I have found they unnerve some passengers especially if they are not forewarned about them.

Jeff you mentioned flying it aggressively. What was it you were doing at the time? So I can avoid it. I do not want to replicate it. I could certainly envision a power on stall with flaps doing something like this.

[Dorsal]

I love slips but I have found they unnerve some passengers especially if they are not forewarned about them.

+1 on this

[n85ae]

I popped full flaperons, at near (or possibly above) max flaperon speed to get
a very steep descent to go down through a hole in the clouds. Nothing
happened when I did this, however within about 5 seconds the tail violently
went up and the nose rotated down and past vertical. Everything in the
cockpit and baggage compartment flew up on the ceiling and windshield (maps,
water bottles, etc.). While this was all happening I managed to lunge forward
and pop the flaperons back to zero. My legs were against instrument panel
bottom and head against the ceiling (my straps were not super tight). I
recovered poorly, and probably did close to a max G above VNE pullout.

The controls came back pretty quickly after I dumped flaperons. However
ahead and above all I saw was ground so I started pulling (just like the
Split-S recovery they teach you to NOT do when you learn aerobatics)

I have since had aerobatics training (yes, prompted because of that
experience). What I have since learned is I should have rolled to nearest
horizon and pulled out but I treated it as a stall recovery rather than an
upset recovery. So I simply chopped power and pulled until I saw the horizon
again.

I will say - That I read your short field full flaperon write up previously, and
had in fact been playing with the flaperons that week at altitude trying to
get comfortable with them. So if I had to give anybody credit for my having
been using them a lot ... It would be Maxwell Duke ...

I won't say it could ever happen to anybody else, but I will never fly my plane
with full flaperons again under any conditions.

The way I was flying the plane was like flying a C-152, when you slap the
lever all the way down and try to get it to come ripping down under full flaps.
It was in my opinion a near fatal mistake. I'm pretty positive I caused a big
airflow burble across the tail and it simply stalled and shot straight up.

I have also installed tiedown rings in the baggage compartment floor and have
a motorcycle luggage net with hoops which anything I don't need to have to
fly the plane gets tucked underneath. I literally landed the plane with pencils,
maps, water bottles, etc. spread all over inside the plane.

Regards,
Jeff Hays

As a data point.
Jeff you mentioned flying it aggressively. What was it you were doing at the time? So I can avoid it. I do not want to replicate it. I could certainly envision a power on stall with flaps doing something like this.

[n85ae]

Maxwell - I'd also mention it was not like any stall I have ever done in the plane
and that includes some very nose high power on stalls with a violent nose drop.
This was like somebody kicked the bottom of the tail straight up.

Seriously think about it. To fly an IO-240B nosed plane, it requires full trim, and
you are holding a lot of back pressure. Consider the aerodynamic load on the
tail in down force. With that much elevator you know the tail cannot be far
from stall. If it stalls it goes up.

I used to fly a Warrior and it was very easy to get the vertical tail to stall if
you try slipping it. When it did, it would pop the nose with a quick yaw snap,
the tail would recover. You could hold max rudder and feel it yaw, then
pop it would stall, the nose would yaw, rinse lather repeat.

So ANY aerodynamic surface can be stalled. People just don't imagine the
horizontal tail stalling. I really am convinced the heavy nose Kitfox can under
certain circumstances tailplane stall.

[SkySteve]

Quote:
Originally Posted by N981MS
I love slips but I have found they unnerve some passengers especially if they are not forewarned about them.

When I first started flying my Kitfox I was surprised at how fast it reacted to any and all inputs I made. Thinking any new passenger would feel the same, I make a point of explaining any and all things to them prior to doing anything, including take-off. I tell them what I am going to do, what it will feel like and then assure them I will be in controll the whole time, then do it. For example, prior to doing a slip, I explain which way the nose will be heading, which way the plane will be heading, which wing will be down, approx how fast we will be decending, when and how the plane will react when I take it out of the slip, why I will be slipping the plane, what to expect right after the slip is finished. I also never slip the plane in a manner that will put them on the low side of the slip unless I have to based on a cross wind. If I have to put them on the low side I try to make the slip as gentle as possible and continue to ensure them thru the slip that I am in controll. The very last thing we want to do to a passenger is scare them.