flying with doors open Max speed?

[jxc]

Evening all

I have a kitfox kfm 112 model 1or 2
Is there a maximum speed flying g doors open?
Can you fly without turtledeck and doors open?

Cheers

[SkyPirate]

I flew my model 2 from april to oct with no doors, i didnt take the turtle deck off, i flew her at 80 85 mph no doors

[Av8r3400]

You NEED to keep the turtle deck on, especially on a I, II or III.

The bearing at the control arm is critical to keep the flapperons from fluttering.

[kitfoxnick]

Speed has never been an issue flying with the doors open. I would caution against slipping towards an open door with just one door open. Make sure that nothing will blow away when slipping with both doors open.

[t j]

I would caution against slipping towards an open door with just one door open. Make sure that nothing will blow away when slipping with both doors open.

Yes, even your headset.:o

[Micro Mong Bldr]

Anybody have a photo of the turtledeck flaperon bushing arrangement? Don't recall one on my Model 2.

[SkyPirate]

I dont have any photo's of my old model 2 flaperon bushings, but, the guy that bought my model 2 lives near Claremont NH, if you get over that way, if you want his info pm me

[Micro Mong Bldr]

Hi Chase,

That would be great, Claremont's not far.

Thanks,

Larry

[Olle1975]

Hello,

I could open my doors (KF3, 582, Prop left turn) but they will close slowly itself. Which liftstruts you have mount, how many newton?

I don't have bubbledoors, above my doors could'nt arise an underpressure between door and wing to keep the door open!?

Thanks!

Olaf

[SkyPirate]

Hopefully, if I can talk the owner into it , i want to get a photo of my old Model 2 and my model 5 together, when im in NH in a few weeks.

[akarmy]

In my series 7 I like it around 80mph, above that it gets windy and noisy and I worry about the doors out there. I've been up to 110mph and it was fine but I mostly use it for a nice warm evening just flying around the local area and 70-80 is fine for that!

Agree with others, don't slip with both open or there will be a lot of wind coming through. Also I had my jacket fly from the back of the baggage area, over my head and out the door while on the takeoff role faster that I knew what was happening. Found it sitting on the numbers at the end of the runway on the next t&g! :)

[MozingoJC]

I have a model 2 and took the doors off. It flies fine 80-85. I did notice a little drag on take off. But doors off is the way to go!

[DesertFox6]

Schoenen Gruss, Olaf -

I suspect your doors close because the gas door spring struts are old and worn out; after a number of years they just lose their holding power. I'm on my second pair of door spring struts on my Model IV; the first ones lasted about 12-13 years. Use the 35 lb.(approximately 47 newton meter) ones for Models I through IV; Part Number 16001.000 in the Kitfox catalog.

The air pressure gradient beneath your wing and above your doors is a highly variable condition but in no case will it keep your doors open in flight. At very high angles of attack you may be able to force the doors to stay up against the wing but then you'll probably be busy recovering from the stall! ;)

"E.T."

[avidflyer]

I know there is some difference between the Avid and Kitfoxes, especially from the Kitfox 4 and later. That being said, I've had no problem flying with the door open on my different Avids, and only the last one had the shock absorber to hold the door open. I've found that there is a fair amount of pressure holding the door against the wing at normal cruise speeds. You can feel the pressure when you start to close the door. Jim Chuk

[Olle1975]

I suspect your doors close because the gas door spring struts are old and worn out; after a number of years they just lose their holding power. I'm on my second pair of door spring struts on my Model IV; the first ones lasted about 12-13 years. Use the 35 lb.(approximately 47 newton meter) ones for Models I through IV; Part Number 16001.000 in the Kitfox catalog.


Hello and thanks for answer but my gas door springs are new, I bought it last year. They have 110 NM and works well on ground, but there is no chance to hold the door open during flight.
During a slow flight by 60-70mph I have to push the door open and you could feel the pressure. If I let the door go it close itself slowly!? Notice, I use a 582 and I have a propwash from left-turn propeller.

May be I have to fly faster? :-)

Olaf

[DesertFox6]

Well, I guess I've run out of ideas Olaf; I've never heard of this particular situation with new gas door springs, but I guess I won't be able to say that again! :o

I flew my Model IV its first full year with a Rotax 583 (a snow-mobile engine quite popular around here until the availability of the 912) which had a "left-turning" prop but never had any such door-closing problems, so your 582 shouldn't be the problem.

I'm beginning to think your doors may have more camber at the forward edge for some reason that's causing a downward pressure gradient pushing them closed. For sure, SOMETHING is overpowering those gas/spring struts and at 110NM, it's got to be something quite significant.

Okay, TeamKitfox; this is where we shine by sharing: Who's got the clue?

"E.T."
Puzzled in Peoria, Arizona :confused:

[Olle1975]

Thanks for your comprehensive reply E.T.

Something I have to add, my gas struts are not mounted in the front of the door like the most kitfox, they are mounted at the rear side, backwards. I think, thats a possibilty to have more camber at the forward edge for getting more pressure during flight!?

My gas struts aren't very strong, it's very easy to pull/push the door open/close on ground.

Next opportunity I try to mount the strut at the front of the door.

Olaf

[DesertFox6]

AHH-HHAAAA! -

By George, I think you've solved your own mystery, Olaf!

This is why it's so hard to diagnose something from the opposite side of the planet without photographs of the offending parts under discussion: We mystics can't see through all the smog on our east coast when gazing at Kitfox problems in Europe! :D

Moving your gas struts to the forward edge of your doors, as originally intended, will no doubt correct your door-closing problems in flight. Don't worry about the struts being up to the job; if they're even half as strong as new, they'll do the job. Those 110 NMs are more than enough to provide many hours of open-door summer flying fun; just move them forward and enjoy the breeze!

"E.T."
(Our "breeze" with the doors open in Arizona right now is 50 degrees C! :eek: )

[Olle1975]

Hi!

I think, I didn't solved my own mystery ;-)
My door-struts in the front don't let the door open during flight.
Look at my doors, they have a little camber in the front. I think, this is the reason for my "problem".

Olaf

http://img.planespotters.net/photo/419000/original/F-JUMY-Private-_PlanespottersNet_419763.jpg

[mtgsxr]

I like to fly with the doors off. it only takes a few minutes. Less drag and no stress on the door frame. off in the summer on in the fall for me. put along at 90-100 all day long.. no issues.

[beeryboats]

Olaf, that is one pretty bird!

[Olle1975]

Thank you very much, it was a lot of work to rebuild this Kitfox.....

Olaf

[Paul Z]

How bad is the wind inside of the cabin with the doors open or off? I would imagine if it ain't tied in you can say goodby to damned near everything.

[mtgsxr]

I wouldn't leave loose papers on the seat but its not bad. left seat gets a little wind near the edge of seat because of prop. but its really not bad. everything in the baggage compartment stays put. Its my favorite way to fly. Of course I started in a Quicksilver lol