Flying with doors open

[John Roman]

Hi Guys,

I now have aprox. 12 hrs on my kitfox 3 with a rotax 912. I would like to try flying with the doors open, other then securing everything inside are there any other precautions I should take or anything I should know.

Thanks

[DesertFox4]

Probably avoid aggressive slips with doors open. The doors can come down quickly even with the gas struts in place. Don't stick you head out or you may loose your headset and sunglasses .


I've had my model 4 up to 125 mph with the pilots door open. No problems. Hopefully you'll never see 125 mph in a model 3. My model 3 was comfortable at 80 mph with the doors open.
Have fun.

[N82HB]

I flew my model III with door open between 75 and 80 and was surprised at how calm it was in the airplane. Now my model IV at least makes enough wind inside to activate the intercom occasionally, but that is at 110-115. You will be surprised how easy the door is to manage while opening and closing; it is almost a 2 finger endeavor.
Kelly

[Monocock]

The first time I did it I spent about 5 minutes making sure my straps were all done up tight and that there was nothing that could blow away. I gingerly opened the door and then wondered why I had been so worried!

It's lovely and even better if you throttle right back to about 55 or 60 mph. If you get low enough you can even smell the barbecues from down below!

The only thing I would say is that if you are wearing shorts (or trousers) with thigh pockets, make sure there is nothing in the pockets. A mobile phone or car keys can easily find their way out!!

I also found that my rather large key fob that was on my ignition switch (located on the far left of my panel) was buffeting around a lot so took that off in case it buffeted so hard that it turned it off!

Someone also said that if you side-slip, make sure that both doors are open or the turtle-deck can pop out due to the side blast. I tend to have the doors shut for landing so can't comment on this.

[t j]

I put a short loop of webbing around the door frame tubing that divides the top and bottom of the door so I can reach it to close the door without leaning out too far to reach the one on the bottom of the door.

[farmboy]

I would not recomend leaving doors open on take off at all. I have a kitfox IV with a 582 and the plane absolutely did not want to leave the ground, granted I had a passenger and and the air was hot and humid. I had been flying prior to that particular flight with a heavier passenger with no problems, but with the doors open on take off it had too much drag and no lift. It was a very poor decision on my part and concider my self very lucky no one got hurt and did not seriously damage the aircraft.

[sdemeyer]

I fly with one door open all the time. Well, not all the time because the weather frequently sucks here but I generally keep the speed at 75 - 80 and that makes for a nice comfortable ride.

I do take off and land with the door open but it does increase your takeoff roll a little. It gets real windy if you slip toward the open door, so I try not to do that much.

Never flown with both doors open at the same time

Scott

[akarmy]

All this talk of doors open flying made me want to go out and do some empirical testing. So last night with temps near 80 I headed out with my series 7 with both door open. Takeoff (with full fuel) was a bit longer than normal and with the doors open the climb out seemed a bit less too. (I know real solid numbers here huh) I flew around for 1.5 hrs at 80mph with doors open. Did a number of stalls, climbs and descents. All fine. Landing seemed like there was increased drag as it was easy to loose altitude and required a bit more power than normal. Full slips were fine with both doors open the wind just rushes through the fuselage and out the other side!

All in all made for a nice summer evening flight. I agree after testing mine a bit that if you need max performance with 2 people etc it's best to close the doors!

[catz631]

How about taking the doors off and flying. I did that one time in a Cessna 120 (years ago) BIG MISTAKE. I got into the air but required full power to stay airborne,couldn't get above 500 ft, staggered around the pattern landed and never did that again !
But that still was not as bad as the time (again millions of years ago when I was much younger) and decided to fly my Starduster 2 on a cold clear day. I had just Armor'alld the seat(BIG MISTAKE !) and it was so cold that I put on my nylon snowmobile suit.(BIG MISTAKE) What a beautiful day it was. I did some acro flew over the field and did a loop. At the top of the loop,I slid out of the seat under the seat belt(the airplane had no shoulder straps) and jammed my knees against the top of the cockpit combing to keep from falling out of the cockpit. That would have ruined my day ! I wasn't able to get back in the seat untill the nose fell thru. Didn't have a chute either (too low anyway)
Tis amazing the stuff you survive while being stupid !
Sure am tempted to pull these doors off and fly around that way. 95 degrees is just too hot !!! Even though I only have 80hp I am sure it is enough on the Kitfox.
Dick

[akarmy]

I know others that have done this on a regular basis each summer. There is almost no wind that hits you with them open so very little drag is created by the opening. I think the performance differences come from the open doors disrupting airflow at the root of the wing when they are open.

[catz631]

Thanks Andy ! Thats what I was thinking

[cap01]

i wonder if there is much difference with the doors removed as opposed to flying one open ?

[Pilot4Life]

cap01, Regarding?

Remember that anything under the wing will effect the basic aerodynamics. Something to consider is that old lift equation that we love so much (L = CL x 1/2p x v2 x S). If you create drag, you'll need more velocity (thrust) to maintain Speed and Altitude. What you're essentially doing, IMHO, is adding drag and disrupting the boundry layer thus making that wing less effective. Perhaps someone that actually owns a Kitfox and flies w/ doors open vs. off will speak directly about that aircraft. Just some food for thought!

[Iceflyer]

Yes nearly did that mistake yesterday. found my phone halfway out my pocket when i remembered this good advice.

Otherwise had great first doors open flight in shorts and t-shirt in 21°c (70°f) Very unusual to have such a warm day in Iceland.

[Monocock]

Iceland won't be very icy for much longer with those kind of temps!!

Glad my comment saved your phone.

[Rob Russell]

I used to take the door off of my Piper Cub J-5 (Cruiser) and never noticed much change in performance. It was fun flying and I did it often in warm weather. So is the Kitfox capable of door off flying?

[cap01]

i tried a short flight with the left door removed . was a real hoot as long as it lasted . it was 70 degrees and sunny when i took off and got really cold once i got in the air with all the breeze of flying . takeoff performance appeared normal as did landing . didnt cruise above 80 , nothing strange there either , except for being cold . the view is certainly better without the door . should be way better for taking pictures , no reflections in the plexiglas . next time it will have to be allot warmer oat or ill have to wear more clothes

[SkySteve]

I've added a light weight nylon chord tied between the top and bottom of the shock absorber type door holder which limits the travel of the door so it can't touch the underside of the wing. This also keeps scratches off the bubble doors from vibrating against the wings during taxi with doors open.

[John Roman]

Hi Guys,
Thanks for all the advice, I now have about 5 hrs of flying with the doors open. I started my first flight with both doors open with no ill afects ( the t/o roll was a little longer then usual). Its the only way to fly on hot summer days, and great for taking pictures.