Flaps

[andy kitfox mk 3]

Wondered if anyone can help with advice on using flaps for take off and landings ? I'm new to the Kitfox world and am Training in a MK 3 with a 912 in England. I have a good instructor but we hav'nt experimented with flaps yet for landing or take off. Any advice would be really appreciated.
Many thanks, Andy

[DesertFox4]

Andy, I had a model 3 with 912 Rotax way back when. I used about half flaps for most takeoffs. It got me into the a little air quicker, shortened the take off distance.

Hardly ever used them for landing.

[SkySteve]

I have model III wings on my bird and the 912 80hp Rotax. Like DF4, I use half flaps when doing a normal take off. If I want to get off fast I go half flaps on the take off role and as soon as I'm at about 30-32 mph I pull full flaps and I'm off the ground. Then quickly push the nose down to stay in ground effect and slowly bleed off all flaps and start my climb. I find this works very effectively.

When doing my normal landing (I most always try to hit a predetermined spot and land as short as possible), I come over the fence stabilized at no more than 45 mph with full flaps, slow to no more than 37-40 mph, touch down and immediately dump all flaps.

[t j]

Mine is a model 4 and like the others have said some flaps on take off get it off the ground quicker.

For a three point full stall landing I do not use any flaps as you will find flaps pitch the nose down on the kitfox.

If I want to make a wheel landing I use about half flaps. My approach speed is the same as for a wheel landing. I set up over the runway with the same 3 point attitude but about the time it feels like it is ready to touch down, sneak in a little throttle...jut enough that your passenger doesn't notice that you are doing it...then keep trying to hold it off and when you feel the main wheels touch, throttle to idle and stick forward to make it stick to the runway.

[HansLab]

Andy, you could consider reading the book 'How to fly a Kitfox': available at McBean's - it's all in there...
And when you're ready hop over the Channel: I'm at EHMZ. More than welcome.

[Paul Z]

I always use one notch of flaps on take off. It shortens Take Off distance, and climbs very nicely. I also use one notch on landing, occasionally I have used 2 notches, but it is mainly because I just missed the first notch. If I don't use one notch, when on base I start slowing down to 75 the down to 70, my *****ing Betty starts yelling at me telling me "Angle Angle Push", "Angle Angle Push", until I put in one notch of flaps, after which she will mellow out until I'm over the fence and starting my flair.

[Slyfox]

I don't know guys. I have the model 4 with the 912uls. I use no flaps on take off. I push the throttle and push forward on the stick. the tail comes up and than I push back on the stick. I use less than 100ft in the process. I'm off the runway and flying out so fast, seesh, why do I need to mess with flaps. On landing I land and stop within 300feet without flaps, why do I need them at all. just my experience.

just so you know, I say within 100ft. might be shorter, I've never got out and measured it. It's quick.

now that this has been said, this is why I dislike flaps on a kitfox. at least mine. use of the flaps makes changes in the aircraft like a trim in the elevator. what that means is if you put the flaps on it will lower the nose, make it heavy. when landing you put on full flaps you now have the nose go down you have trouble with level flight. now it takes a lot of effort to flair when it's time. with my plane I leave the flaps alone (neutral) and fly in on final, I adjust the trim in the elevator(yes I have electric trim in the elevator, real nice) and fly it on in. stick pressure is none. I slow to 50 over the numbers, still no pressure on the stick, wait for the right moment and pull back on the stick. nice settle on the runway, no surprises. :D

[andy kitfox mk 3]

Dear Desert Fox 4 , Sky Steve , tj , Hans Lab , Paul Z and Sly fox,
Cheers for all your advice and experience.It seems all our home built aircraft are slightly different and have different characteristics - mine will be no exception especially as it has later wings with flat bottomed wing ribs.The most worrying thing for me is the nose up attitude with flaps extended and then running out of back stick movement in the flare , but we'll experiment with them next week and let you know how we get on.
Thanks for the tip on the book Hans - and yeh - definitely want to cross the Channel - maybe later this year sometime ?
Thanks again Fellas for your help,
Andy

[HansLab]

I'm in the same process (look at my posts) C&G, flaps, trim via the flapperons, have I build her right?
I noticed that not only the setting of the flapperons is one element for balanced flight, but rev's as well: the 912 I have has a slight upward motion, so it seems. More power means more up.

Yesterday I threw out all the water-weight (16 KG in the baggage-compartiment), added no weight in the tail at all - having lowered the elevator to the lowest hole, started her up and flew 4800RPM - effortless.

there's much to learn.

Fly safely!

[SkySteve]

One additional item you may want to consider is gap seals. I gap sealed my elevators and the difference in elevator control during slow flight and landings was quite noticeable (read better, more controll). I will be adding gap seal to my rudder in the next week or so.

[andy kitfox mk 3]

Sorry - i meant nose down attitude with flaps selected , thanks again for more ideas - sealing the gaps on the Elevators sounds a good mod. what material did you use ?

[SkySteve]

Andy,
I used clear 2" wide Duct brand tape. Put the elevator down all the way and taped across the top of the gap. Then put the elevator up all the way and taped across the bottom all the way. I did this 4 years ago and it is still tight and in good condition. Other people have other methods.

[cubtractor]

I sealed my elevator gap and installed vg's on the underside of the horizontal stab. Made a big difference. I used Blenderm tape for a gap seal. It is semi-transparent, sticks well, removes easily if needed and is stretchy.

[andy kitfox mk 3]

Cheers for that gents , i'll order some up.