This is a video of my vintage tailwheel reaction trainer, designed and built by the late Bert Sisler, who was an aircraft designer, mechanical engineer, and airline pilot. As far as I know, it's the only one in the world.

The first half of the video shows an "easy" setting, the second half shows a pilots-eye view at a much more challenging setting. The "fuselage" is mounted on a rearward-angled pivot, so it is statically unstable and always wants to fall to either side. The rudder pedals are connected with bungees to the base, and the sensitivity is adjustable. The input/delay/rebound/need for secondary corrections is very realistic and keeping the fuselage centered requires constant attention, especially at the more sensitive settings.

If the fuselage swings too far either direction, it is not recoverable and you have groundlooped. This trainer works very well to help my new tailwheel students understand what they need to do to keep it rolling straight on the ground.

https://www.youtube.com/watch?v=07I7D2C0CHc

That's really cool!

Genius! I'm totally stealing this concept. As a CFI who used my Citabria to sign off several tail wheel endorsements it occurred to me a long time ago that the actual learning takes place in the flare and roll out. How could I eliminate the useless (to a rated pilot) lap around the pattern and get a student as many repetitions as it takes until the light goes on?

I've apparently been thinking too hard. I was going to make a reverse trike with bicycle wheels using electric hub motors, or make a Penguin Trainer.

aftCG wrote:I was going to make a reverse trike with bicycle wheels using electric hub motors

That would actually be pretty slick. Use a real aircraft tailwheel.

I would make it with tandem seating and heel brakes

Make sure it has some sort of structure partially blocking the view straight ahead (I need to add something to the front of my simulator to block the view so you can't look straight ahead between your feet)

I would have the CG fairly close to the ground to prevent tipover if groundlooped.

That's neat! Wish there were more of those floating around to wake aspiring TW pilots feet up prior to getting in the airplane.

I never understood why more wingless airplanes were not used. The AAF used wingless Stearmans during WWII to improve and speed up before solo training.

In your video, the female pilot did better than the male. Yes, less sensitivity, but she used rapid dynamic proactive rudder movement and he used very gross and late reactive rudder movement. There is nothing wrong with gross, to the stop, rudder movement so long as it is dynamic and proactive. On short final, flair, touchdown, and rollout, we need to stay ahead of the tendency to ground loop by bracketing the centerline between our legs with continuous dynamic proactive rudder movement. Like your lady pilot on your simulator, we are better when we move. Be more positive and call it the Vintage Tailwheel Longitudinal Axis Alignment Simulator. Any Reaction is too late. By causing slightly off alignment left right left right rapidly, dynamically, and proactively, we bracket perfect alignment.

There is a perfect simulator for helicopter: the unicycle. Now dynamic proactive has to take place in every plane. We are better when we move. It cannot be stabilized without movement. Ground loop prevention, much easier than hover, cannot be stabilized without movement. The deceptive problem is that the tw airplane occasionally runs true on its own, but not for long. Deceptively, reaction in time gives the illusion that ground loop is being stabilized. Not so. It is just being reacted to.

Walk the rudder anytime it is necessary to perfectly bracket and thereby maintain a target.

My 16-year-old daughter who had zero hours flying a plane at that time of filming will be flattered by your complements, I told her to keep it centered and figure it out, this was after about maybe ten minutes of practice. She also can ride a unicycle.

I am the guilty party in the second half, it was my first day with it, it was set on a very loose/sloppy slow ground speed setting which is actually very similar to our Cub- we keep the tailwheel chains slightly loose, otherwise the detent will release before the rudder reaches the stop.

Every experienced TW pilot who had tried my simulator has said it was pretty realistic

The simulator is not ever intended to to teach anything about flying, it's for developing an understanding of what it will be like keeping it straight on the ground. I am thinking of a way for the user to adjust sensitivity on the fly, using a throttle-type lever

20 minutes is probably the most anyone would ever need in the simulator to get the push-and-recover reflexes figured out, anything after that is pretty pointless and further training should be in a real airplane.

On the rollout, as you slow down, rudder input frequency decreases, and amplitude increases. Opposite when accelerating on the ground, as rudder inputs become smaller but more frequent

My local airport has this contraption. I haven't had a chance to try it out, but it looks like fun.

TheScaryDoor wrote:My local airport has this contraption. I haven't had a chance to try it out, but it looks like fun.

Conceptually, that is exactly what I had in mind. That even appears to have heel brakes.

The simulator is not ever intended to to teach anything about flying, it's for developing an understanding of what it will be like keeping it straight on the ground. I am thinking of a way for the user to adjust sensitivity on the fly, using a throttle-type lever

20 minutes is probably the most anyone would ever need in the simulator to get the push-and-recover reflexes figured out, anything after that is pretty pointless and further training should be in a real airplane.

And there you go. So, back in the day I taught my kids to ride bikes at a very young age. I had it down to a science and could teach a kid to ride in minutes. My youngest was 2-1/2. There is nothing about center of gravity or counter steering that you can explain to a three year old. But if you can let them get the feel for something in a gradual, non scary way they catch on super quick.
I slammed the seat down as far as it would go, and removed the peddles. The kid duck walks the bike around getting used to it. It helps if there is a gentle slope but flat ground still works. The kid gets the bike going with their feet and picks them up enough to glide. With their feet spread they can catch themselves, but they glide longer every time. You'll see the light go on and then it's time to put the pedals back on and adjust the seat.

These bikes are commonly available now and typically called gliders. I wished I had cashed in on the idea at the time but I don't really think there's much to patent or idea to defend. But your statement about it only taking about 20 minutes on the tail wheel simulator is spot on. After that it becomes no big deal.

That day I taught my youngest to ride, I put the pedals on and was putting my tools on the porch and had my back to the kid while I was telling him what the next step was. I turned around and he was riding down the street.

So what are you adjusting when you change settings? Is it the tension in the bungee chords, the angle of incline, the pivot point or what?

Lastly, before there were wingless Stearmans there were Penguin Trainers. I've got a junk set of Kitfox wings I'm thinking of cutting down and making something like this. Penguin = flightless bird. These don't have enough power to fly but get them up on one wheel and you can sure get a feel for control sensitivity and wind direction with minimal skin in the game.

So much of flying can be that natural, aftCG, when we let it. And teachers teach by making learning experience (stick time) available. Instructors prepare pilots for flight tests. Like learning to ride a bike, learning to fly is not complicated, it doesn't require higher math, and even we disorganized people can do it. Youth and inquisitiveness are big advantages, however.

aftCG wrote:

TheScaryDoor wrote:your statement about it only taking about 20 minutes on the tail wheel simulator is spot on. After that it becomes no big deal.]

Think about how many trips around the pattern it would take to get an honest 20 minutes of takeoff roll/landing rollout time. I might spend 5-7 seconds on takeoff from the time I hit the gas to liftoff, and maybe 20 seconds at most on landing rollout from touchdown to stopped.

aftCG wrote:

TheScaryDoor wrote:So what are you adjusting when you change settings? Is it the tension in the bungee chords, the angle of incline, the pivot point or what?]

All adjustment is in the bungees- you can adjust tension, and you can adjust the strength using a fatter/skinnier cord. I use paired adjustable-length cords on each side- a fat cord that is almost under no tension in the neutral/centered position, and a weaker cord next to it that always has some tension. The stronger cord comes into play as you increase pedal deflection. I don't have it exactly where I want it yet, but it's close.

If the bungees are too tight and strong, you can just freeze the pedals and it will stay centered, so the "easier" settings use tighter bungees. I'm sure something could be designed with a variable cam (like a Nautilus weight machine) that would really amplify the reaction the further you deflect the pedal, but the current setup is simple and works. Anyone in the Minneapolis area is welcome to stop over and give it a try.

Thanks also to FlyingSignPainter for the excellent two diagrams of the energy management turn and the one diagram of the cockpit view of a biplane making an angle across the runway using the apparent brisk walk rate of closure approach or any power pitch approach to the downwind corner of the runway while aligned with the upwind big airplane touchdown zone marking. I have sent those diagrams and that picture out with every attachment of Safe Maneuvering Flight Techniques to BCP and the weekly (Wednesday) PilotWorkshops site when I comment there.

FlyingSignPainter has a graphic/design/artistic feel for maneuvering flight.

I was told to go to a grocery store, load up a cart with canned goods, and push it down an aisle as fast as I could, with the cart backwards. The inherent stability will be quickly apparent (CLEANUP ON AISLE 4!) Do the same with the cart oriented normally.....THAT is the difference between tri gear and a taildragger.

Hello Courierguy, I shot you a PM a month or so ago. Wondering if you got it.

Pete

courierguy wrote: I was told to go to a grocery store, load up a cart with canned goods, and push it down an aisle as fast as I could, with the cart backwards. The inherent stability will be quickly apparent (CLEANUP ON AISLE 4!) .......

Another good example is an old rear-wheel-steering forklift,
driving it backwards vs forward.
Once when I was a kid, I was in danger of getting whistle-bit at quitting time (heaven forbid),
and got in a rush putting the forklift away at the sheet metal shop where I worked.
Ground-looped it and managed to run the forks right through the metal siding on the shop.
No, I didn't get fired, but I got about half my ass chewed off.
I was pretty careful (about driving the forklift anyway) afterwards.

Awesome concept, that's super useful for new tailwheel pilots. For me, once I read about the "balancing a broom" comparison, it all started to click for me.

The advantage of balancing a broom on ones hand or riding a unicycle or any extreme balancing problem is that they demonstrate the absolute necessity of dynamic proactive movement to bracket the balance point. There is no question that we are better when we move. The disadvantage in teaching or learning tailwheel longitudinal axis alignment is that reactive tailwheel movement, rudder movement, or even differential braking can manage to correct misalignment if that reaction takes place very quickly.

So to save tailwheel airplanes from the total destruction caused by ground loop at high speed, dynamic proactive rudder movement needs to be built into tailwheel ground loop prevention simulators. Also, teaching dynamic proactive rudder movement prevention of rather than reaction to ground loop works well. As with anything in aviation quitting flying (dynamic proactive rudder movement) before tied down can be destructive.

Dynamic proactive movement prevents the need for reaction.

CompSciAndFly wrote:Awesome concept, that's super useful for new tailwheel pilots. For me, once I read about the "balancing a broom" comparison, it all started to click for me.

Funny, I do have a broom in my hangar which I use during the first ground discussion of a candidate for tail wheel endorsement. It demonstrates the concept of something which is not inherently stable but does not do anything for the foot/eye coordination needed to even taxi.

I'm actively designing a simple, cheap version of this device shown by the OP. I almost bought some welding equipment but realized that would be a rabbit hole I would never return from. My intent is to design something anyone can assemble like Ikea furniture (so even a pilot could do it).