How can i keep my kitfox from stalling & spinning in too ????

[Dave S]

Hi Roger,

You can't make a Kitfox stall/spin proof - same is true of virtually all airplanes. Some of the "spin resistant" airplanes out there can even instill a bit of unwarranted trust in the plane - if one of them ever does manage to get into a spin - it can be as difficult or worse to get it out of the spin.

What I found in testing our series 7 is that power off coordinated stall are extremely gentle - A person can literally go to 5,000 ' in a kitfox - power off and do a dozen or so consecutive "glider stalls" (meaning stall recoveries without the use of power) and you will be surprised how gentle they are and how little altitude is lost with a power off stall recovery (which is real good to know).

Power on stalls with full flaps and partial power (3/4), provided you stay coordinated, at least in my experience with our plane are more abrupt but entirely manageable.

For the record - I did not do any spin testing of the airplane on the basis the design was not really tested for that purpose in its development. Yes, I know - people have done spins in a kitfox; they can go ahead an do that on their nickel - I won't - that's just me.

OK - full flaps - the series 7 is set up for half flaps and full flaps. what I found in testing is that there is a pretty significant stall speed reduction with half flaps and no noticeable change in handling compared to retracted other than the nose attitude changes. I also found that going to full flaps does little to further reduce stall speed but significantly changes the yaw characteristics - so much so that I almost never use full unless on short final in calm conditions.

I think a person has some potential to scare the living crap out of themselves with a full power, full flaps stall in an uncoordinated condition in a kitfox.

You prevent stall/spin deals by becoming more knowledgeable and consequently more confident about your ability control the aircraft. This is all about aircraft control.

Your comment "Or maybe just flying it only in a particular manner" really is the answer - and, the particular manner means 1) keeping the airplane coordinated especially in turns in the pattern, 2) keeping your airspeed/wing loading within reason (which keeps the angle of attack of the wing out of a stall/spin range). You are correct in following this reasoning - it's all about how you handle the aircraft.

The big problem with stall spin accidents it is the fatal type stall spin usually occurred at such a low altitude that a recovery was impossible.

If a stall/spin occurs at 5,000 feet - there is air below you to sort the mess out. If it occurs at 500 - it's going to end up being an auger job. Bottom line - don't stall spin at low altitude. Back to correct operation and training.

A highly recommended thing is to get some spin experience in a spin approved aircraft with a PROFICIENT spin instructor. I got curious enough to do that some years ago and what I can tell you is the experience (which is done at sufficient altitude) makes it absolutely clear to a person that you simply cannot allow a stall spin to develop at low altitude once you find out how much altitude is really needed to do the recovery. The second thing the training does is really helps a person understand what makes a stall spin happen. Once you know what makes it happen you know exactly what to do to make it not happen.

The US standards do not require spin training for a PP cert - other countries do and I think it should be done here too.

You're on the right track - just go out there and work your plane and get some spin training in an approved plane if you can - it'll do wonders for a person's confidence.

Sincerely,

Dave S

[Av8r3400]

"I'd rather die trying to live, than live trying not to die." The motto of someone I know...


Seriously, though, I have to agree with Leni, these plane really need to be abused to stall-spin. If you get a little transition training and learn to fly the airplane properly, you will have no issues.

These are very safe planes, in my opinion. That's why I fly one.

[akflyer]

I live by that every day! But I have learned that dying trying to live does not include sheer stupidity I gave most or that up a few minutes ago hahahaha.

[DesertFox6]

Roger -

To plagiarize a slogan from the firearms fraternity; "Spins don't kill pilots...PILOTS kill pilots." And the reason they do, with regards to spins, is a lack of knowledge, due to a lack of exposure, which is an altogether unfortunate bi-product of a systematic training philosophy that ignores teaching spins as a natural-occurring outcome of inducing yaw on a stalled airfoil.

Esser hit it right on the head; go get some "upset/spin" training with an experienced CFI who can teach you to not only deliberately spin with confidence, but recover them on a specified heading (yeah, no kiddin'!) and you'll never get the jitters about slow-flight again. You'll be ever-so-glad you did, as our Canadian friends will readily testify!

Airplanes don't do anything without a pilot except age...

"E.T."

[jtpitkin06]

Let’s go back to your original post. You are concerned that 50% of fatalities in Kitfox are stall spin. But you don’t mention accidents per flight hour compared to other aircraft. The 50% stall spin figure is in line with other light aircraft. However, I think you will find per flight hour, the Kitfox enjoys an enviable safety record.

Your other concern is how to make the Kitfox fly like a 601. Thankfully, that can’t be done. The Kitfox has delightful flight characteristics and capabilities that the 601 just can’t match.

Consider the Kitfox short field takeoff and landing performance. You don’t get that without a high lift wing flown at high angles of attack. Flying in that part of the envelope requires responsive flight controls. We could make the Kitfox a gentle little kitten by limiting control authority, but you wouldn’t be able to do steep descents at slow speeds with any flare ability left over. So let’s not change a thing.

Lastly you seem to have a fear that the Kitfox will stall and spin without warning. That's just not true.

I’ve taught stall/spins for 42 years and have done thousands of them. I think of a spin as simply another aircraft maneuver. It’s nothing to fear. I don’t accidentally spin an airplane any more than I accidentally turn an airplane upside down. It’s something you have to do deliberately with control inputs. Unfortunately, inexperienced pilots will sometimes skid around turns at low speed and low altitude. That's a condition that can set you up for a stall spin in any aircraft.

To eliminate your fears, get some spin training. It’s fun and it will make you a better pilot. While you're at it, ask for some unusual attitude recovery training, too.


JP

[Dorsal]

Another note on safety is that the Kitfox has one of the lowest fatality per accident ratios of all amateur built planes. As was pointed out further up that may be why the stall spin numbers look high, most of the other incidents where non fatal.

[rogerh12]

Wow, got a lot of response on this one !!!!
Well I guess I am poking for something more than just "being a good pilot", What about increasing the wing tip washout? Wouldn't that help keep the plane from entering a full span stall, and also help to keep wing tip control during a spin? What about increasing the rudder effectiveness with gap seals, wouldn't that help a pilot exit a spin earlier?

[DanB]

Roger,
Please don't overlook the excellent replies you have already been given. The Kitfox is as stable a platform as you will find anywhere. The stall / spins you have interpreted into being a performance issue with the design points firmly to pilot error. The suggestion that came up more than once to get some spin training came from at least one CFI who has known his way around a Kitfox for the last 20 years. Take a little more time to read here in the forum (or other places) about these planes and you will find nothing but praise and satisfaction for the performance of the craft. Your comment about rudder authority leads me to believe you have not flown in a Kitfox yet. If this is the case, go try one on then tell us what you think.

[jtpitkin06]

Roger,
I think we have given you the more than gentle nudge in the right direction. However, you brought up some interesting points about washout and spins in general. So this response is not only for you but for anyone who has not done spin training.

Modifying the airframe is not the answer. More washout in the wing will not make the plane spin proof. It may, in fact, spin easier with more washout. Spin easier? Yes… remember a spin is when one wing is stalled and the other wing is flying or partially stalled. If you have more washout in a wing it reduces the angle of attack at the tip. The partially stalled wing is likely to remain flying and promote the spin.

More washout also reduces climb, cruise performance and increases stall speed. Yes, increasing washout increases stall speed. The angle of incidence at the root is higher than the tip and the root will stall before the tip has a chance to produce maximum lift. Adding more washout further reduces the lift produced at the tip and the aircraft stalls at a higher speed.

Washout does delay the stall at the tip to improve roll control when landing… but at a cost.

Now,Spins in General

Generally, I find pilots who have never done spin training are less comfortable practicing stalls because of fear they may enter a spin and not know how to recover.

So just how do you get into an inadvertent spin at low altitude?

Remember this… Most airplanes need to be forced into a spin. Here’s how you can force a plane into a spin:

To practice this maneuver we’ll do it at a safe altitude where we can demonstrate it and have room to recover. How about 3000 AGL for starters?

Let’s say you are a pilot who skids around the traffic pattern by stepping on the rudder while peeking under the wing. We’ll go through what happens in a left turn from base to final.

You’re stepping on left rudder and holding right aileron to keep the aircraft from banking too much. Either you want to peek under the wing or you are nervous about banking at low altitude. In either case the right aileron is up, the left aileron is down and the left wing has the highest angle of attack.

The skidding increases drag and the aircraft starts to get low. To correct your path you add power and pull back on the stick.

The power and torque want to roll the airplane left so you add more aileron to the right. The left wing now has lots of aileron and a high angle of attack. The aircraft continues to sink with all the drag.

Now, dangerously low, you jam in the power and pull back on the stick. Whoo Boy!!! This is going to be fun.

The prop blast on the elevator causes the nose to pop up. The sudden increase in angle of attack causes the left wing to stall. The stalled left wing now has high drag and the aircraft yaws left. The right wing has up aileron and it continues to fly

The left wing quickly drops. The aircraft is now inverted and spinning with enthusiasm. Attempting to roll the aircraft level you put in full right aileron. The aircraft continues left as it flops to right side up and continues spinning (right side up) until you do something different.

Relax… neutralize the ailerons. Simultaneously reduce power to idle, apply right rudder to stop the rotation, apply forward stick to break the stall. Wow! You’re flying again… albeit a bit nose low, so pull out of the dive. Whew!!!

Hey that’s a hoot!!! Let’s do it again. In fact, do it in both directions with and without power, you’ll see quite different spin rates.

So what’s the answer? Coordinated flight is the best spin prevention. You simply cannot enter a spin without a yawing force and you won’t get that with coordinated flight. Have you practiced stalls in a turn? Can you maintain a 30 degree bank while doing a power off stall and recover while still turning in a 30 degree bank?

If you haven’t done spins, find an instructor and aircraft to do spins with and have a good time. I highly recommend it. The fun meter will be pegged at 100% and you will be a much better pilot at the end of the ride.

If you are building a Kitfox, be sure to include spins in your operating limitations. The Kitfox spins and recovers very nicely. The aircraft does not need to be in aerobatic category to include spins. Normal or utility are acceptable. The DAR will show you how to do the logbook entries while you are still in Stage 1.

Have fun guys and gals.

John Pitkin
Greenville, TX

[Tom Waid]

Coordinated flight is the best spin prevention.

John Pitkin
Greenville, TX

We all need to say that again... and again... and again...