Those that have, those that will...

[Nark]

[Beefitarian]

So who has had a ground loop?

[nacho]

I thought it was about cutting a power line...

[North Shore]

Is that Clark Gable narrating?

[Nark]

So who has had a ground loop?

The good Lord know's I've come close.

I haven't flown a real airplane in over a year, I miss it.

[Shiny Side Up]

Very interesting video to watch. You can see the point where shit's went wrong often. There's a few (the couple where the camera is facing back towards the tail) where it looks like three was a problem with the tailwheel or the linkage to it. Those shots its interesting to watch how busy that rudder is too.

[Hedley]

who has had a ground loop?

Zero in 38 years so far, but Lord knows I've had more than a few students who were determined to do so. Teaching tailwheel is like working on a leaky nuclear reactor. Regardless of how much you're paid, it's never enough, because of the years taken off your life.

[nacho]

At 5:00 that is an Air Tractor....Wonder if he has been through a power line yet or the ground loop came first ...

[Rowdy]

Love the one at the end..

"are you shitting me?!?!?"

[beaverbob]

Very interesting video to watch. You can see the point where shit's went wrong often. There's a few (the couple where the camera is facing back towards the tail) where it looks like three was a problem with the tailwheel or the linkage to it. Those shots its interesting to watch how busy that rudder is too.

That is a common problem with a lot of light aircraft tail wheels. Happens when needs to be tightened and lubricated, or when is worn. It is not the linkage though. It is inside the swivel. It can vibrate bad enough to shake your back teeth loose.

Bob
PS, I had one ground loop in a crosswind from the right when I needed a bit of left brake and it chose to fail at exactly that time. If you plan for no brakes it can be done but not if it is unexpected, and yes, Hedly, I did a brake check on final.

[Hedley]

Tailwheel shimmy can drive you nuts. Yes, replacing the entire tailwheel assembly (including the two steering horn springs) can help, but you also need to check for the leaf springs aging and losing their arch, which results in trailing castor geometry, which can be a root cause of shimmy.

It can vibrate bad enough to shake your back teeth loose

Correct - tailwheel shimmy - which sounds harmless enough, like a 1950's dance - is bad news. It can scrub the tread right off your tailwheel tire. It can break your tailpost. I've seen both happen.

How you get rid of tailwheel shimmy, btw, when it happens to you, is to reduce the weight on the tailwheel. It has been my experience on many different types that weight on the tailwheel generally makes the shimmy worse - see above castor geometry.

Does anyone here ride motorcycles? On sport bikes there is a phenomenon known as a head shake or tank slapper, when the front tire bounce back and forth violently enough to really smash up your thumbs. It is really not pleasant. On my RC51 I got rid of it by installing a Scotts damper.



All of the new sportbikes now have fancy speed-variable dampers now, installed by the manufacturers, which I think is a great safety move.

I'm hoping I don't have to stuff too much butter up anyone's @ss to pass this info along in a sensitive, new age kind of way.

[beaverbob]

Nope, no butter up my butt. I might have to stuff a bit of butter though after my lesson.

[Hedley]

ground loop in a crosswind from the right when I needed a bit of left brake

First of all, you did the right thing by choosing the crosswind from the right. 99% of pilots will make the wrong decision when faced with a direct crosswind - they will choose it from the left, which is a very poor choice.

Anyways, I presume that you weathervaned to the right as you rolled out. Why didn't you simply apply a burst of power to torque the aircraft to the left, and straighten it out? I have had to do this repeatedly in the past, to the point where I ran out of runway and had to overshoot and go around. This was around 20 years ago, when I was intentionally playing with a 25G40 knot direct crosswind in my Maule M4-210C.

FWIW when I teach tailwheel to people, I start them off with no brakes. All too often, pilots panic, lock up the brakes, and flat spot the tires and shear the tube valve stems off, by abusing the brakes. Once they demonstrate that they can take off and land without brakes, then they get brakes. Gotta teach it right, the first time.

Frankly, I don't understand what all the fuss is about tailwheel flying. I will start using more product in my hair, and go get a manicure and pedicure, and see if that changes my perspective.

I know this is old-fashioned of me, but I fly closed-loop, not open loop. Very simply, do not fly by rote. We are not baking a cake here. Instead, do whatever it takes with the flight controls, to make the airplane do what you want. Look outside. The same is true, when you are flying a hammerhead. Look outside. Use whatever flight control inputs are required, to make the airplane do precisely what you want it to do.

Interestingly, people struggle with hammerhead, too, because closed-loop control is required, instead of a white shirt, gold bars checklist method.

Ok, all you delicate types, I'm in a good mood this evening. Line up and bend over and we'll use up a few bars of butter to make you feel good, which after all is the most important thing in aviation.

[TG]

The one at 7:53 is a bit unfair.
This P-51 suffer an engine or partial engine failure bang on short final. Giving no option but to "land" before the threshold.

[Beefitarian]

At 5:00 that is an Air Tractor....Wonder if he has been through a power line yet or the ground loop came first ...

Ok, just yikes. This makes me wonder if someone has done both in one really bad day?

[Slats]

How you get rid of tailwheel shimmy, btw, when it happens to you, is to reduce the weight on the tailwheel.

I fly a 185 that has an awful shimmy. I try to keep the tail up as long as possible given the conditions of the day, then when it wants to come down, try to slow to taxi speed as quickly as safely possible. Seems to work well for me, but I'm no guru.

[beaverbob]

How you get rid of tailwheel shimmy, btw, when it happens to you, is to reduce the weight on the tailwheel.

I fly a 185 that has an awful shimmy. I try to keep the tail up as long as possible given the conditions of the day, then when it wants to come down, try to slow to taxi speed as quickly as safely possible. Seems to work well for me, but I'm no guru.

Just take it to the maintenance. It can cause a lot of trouble if left. There is a lock inside the tail wheel (not the wheel itself) and it could be worn. Hedly probably would be the one to answer how it is built.
Bob

tailwheel_geometry_small.jpg (51.55 KiB) Viewed 2091 times

[iflyforpie]

The tail wheel lock is typically just a metal tang shaped like this: \__/ that goes inside a circular housing with two sharp recesses where each of the tangs lock. If there is enough force, the tang on the outside of the turn deforms an pops out (the opposing one merely sliding out), allowing the tailwheel which is attached to that housing to free castor.

If the tang has worn or lost its spring, or the recesses have become rounded, your tailwheel will not lock as well. This doesn't usually contribute to shimmy, as there usually is enough play in there for that to happen anyways given the right circumstances, but will make your plane more sensitive to crosswinds when taxiing (akin to not keeping the tail planted).

[Hedley]

IFP is right - in my experience, popping in and out of the detent isn't often the root cause of shimmy.

And yes, learning to wheel land sure helps with a misbehaving tailwheel!

[Cat Driver]

When reading these posts one must treat the forum like mining for gold, you have to dig through a lot of dirt to find gold.

This nugget by Hedley is priceless and should be stickied so people can keep reading it.

I know this is old-fashioned of me, but I fly closed-loop, not open loop. Very simply, do not fly by rote. We are not baking a cake here. Instead, do whatever it takes with the flight controls, to make the airplane do what you want. Look outside. The same is true, when you are flying a hammerhead. Look outside. Use whatever flight control inputs are required, to make the airplane do precisely what you want it to do.

[Cat Driver]

And yes, learning to wheel land sure helps with a misbehaving tailwheel!

The wheel landing is the first type of landing I teach when doing tail wheel conversion training, right after the high speed runway training.

[cgzro]

Ouch .. interesting video. That last P51 'incident' must have cost a fortune.

I've never had problems in my own aircraft but did manage to test Hedley's reaction times once .. his reflexes are still good .. in my own plane I spend a lot of time making sure my seating arrangment etc. pedal throws are perfect but sometimes in training you go with good enough .. unfortunately in a tail dragger you need excellent pedal feel/control and you should not fly even in instruction if you don't have things feeling just right. Proper shoes etc. are also critical.

[iflyforpie]

I remember doing my first taildragger landing in a T-Craft and feeling the owner's sudden jabs of the pedals reminding me that I wasn't dancing enough.

He must have trusted me enough because there are no brakes on the right side. Mind you, the brakes on the left side are pretty much useless anyways...

[Hedley]

test Hedley's reaction times

Geez, I'd forgotten about that. All I vaguely remember is me dozing away - you're an old pro in the Pitts - and suddenly I had to wake up during a landing.

What is it that someone said, about the most dangerous thing in an airplane is two experienced pilots

"I thought you removed the external flight control locks"
"I thought you removed the chocks"
"I thought you undid the tiedowns"

[Rowdy]

What is it that someone said, about the most dangerous thing in an airplane is two experienced pilots

I thought it was two instructors