Touch and goes in a small taildragger

[kevmusic]

...or in a Turbulent, to be precise. Last week I flew this little beastie for the third time and decided, at the end of the flight, to treat myself to a touch and go. Now I've done this in a Cub before (benign), a Jodel D150 (also benign) and a Tiger (less benign) so I'd no reason to suspect that this would be anything other than a doddle; particularly with the wind, which was about eight knots down the runway.

The trouble started when I opened up after landing and lifted the tail. Then she had a life of her own. I explored both sides of the runway like a dog let off the lead, and by the time I gratefully reached the sanctuary of flight I was so far off to the right I had to do a gentle left-hand clinbing turn to get back over the runway.

That was when phrases like 'gyroscopic precession', 'torque' and 'propwash on rudder' started hitting my brain. It would have been good if they'd hit it about a minute or two earlier, but better late than never. :}

So, what happened? The VW engine rotates anti-clockwise as the pilot sees it, but that's about all I know. Does anyone know precisely how these forces affect a small aeroplane like the Turb?

[Genghis the Engineer]

I've not flown the type, but quite a few other taildraggers both smaller and larger. Looking at a picture of the turbulent, my instinct is that this isn't entirely down to the size of the aircraft.

The back end of the turbulent is very high and slab slided, which implies quite high directional stability. At the same time, it's a very light aeroplane: I'm guessing that you were flying at a weight of around 270kg? That very low inertia gives it a very rapid response to perturbations.

So, I'm guessing that that combination of very high directional stability (causing the aeroplane to follow every little variation in the wind) with very low inertia is that you were experiencing - particularly the latter: this is probably under half the weight of anything else that you've listed flying.

The solution is probably only practice - but you could look around and see if any microlight schools are training on a Thruster T600N sprint, which is a 2-seater likely to be reasonably representative.

G

[peter272]

When I flew the Turb we used to laugh at early attempts. They are light and twitchy at all stages of flight. You need to look well ahead to watch for any swings developing and correct early.

It's not for no reason that we placarded the aircraft to say it is not aerobatic - it certainly feels that way!!

[blueandwhite]

All the forces work in the same way on a small aircraft as a bigger one - but in the opposite direction if the engine goes the other way. Maybe as the engine is going the other way it caught you out as you need the opposite reaction. (Put it down to getting ready to fly a Spit. :p)

I don't remember the Turb as being particularly sensitive to rudder more than the other controls. PIO was a feature of new members first flights.

[Them thar hills]

Kev
"to be precise" - Your own words.
But you weren't precise enough !
One major difference. Small aeroplanes like the Turb, Taylor Mono, have far less inertia that the Cub, Jodel, Tiger, so things happen much quicker, including any swing, as you describe..
Next time, don't let it wander off heading before you do something about it !. :)

[rotorfossil]

Also discovered touch & go's in monowheel Europa's can be exciting. Best not to get on the power too soon or you just reach full power as the tail lifts and the yaw and roll all happen at once. Let it slow right down, get on the power, then lift the tail.

[sycamore]

Kev, look in the local paper and see if there are any `oldie tea-dances`,go and enrol,and learn how to `pedal your feet. Buy a pair of ballet shoes,and go fly !!
You should practice overshoots/go-arounds at a safe altitude,and then try a roller,but don`t be in a hurry to open the throttle quickly unless the feet are working to the same rhythm,and don`t be too keen on lifting the tail too early...but then..I guess you know that now...It does`nt have to be a big Merlin ,or Pratt up front( unless it`s the one in the cockpit !) to spoil the day....
It can be a bit of a `skateboard on ice` if you are`nt ready; make sure the runway is long enough as well,otherwise one can rush it,if the hedge is looming....

[Flyin'Dutch']

That was when phrases like 'gyroscopic precession', 'torque' and 'propwash on rudder' started hitting my brain. It would have been good if they'd hit it about a minute or two earlier, but better late than never.


Suspect the twitchiness has more to do with the general configuration of the aeroplane than that powerful engine prop combination!

:}

[Speedbird48]

Kevin,

It could also just be the rate at which the throttle is shoved open?? Softly, soflty catchee monkey if you get my drift.

I have done some intersting check rides with pilots that seem to think that the throttle must go forward at the speed of light!! And that is in anything from small GA to large jets.

Not saying that you do this, but always worth a thought.

Speedbird 48.

[Lister Noble]

Kev,I never do touch and goes, I'm either down or up,so you're one up on me!:););)
Lister
And how's the music?

[barit1]

May I second sycamore's advice:

You should practice overshoots/go-arounds at a safe altitude,and then try a roller,but don`t be in a hurry to open the throttle quickly unless the feet are working to the same rhythm:eek:...

My father insisted on students demonstrating this to themselves. In the ancient BT-13, often the student would discover the landscape from a new perspective! :eek:

[John Farley]

The trouble started when I opened up after landing and lifted the tail.

May I suggest that the trick is to do both these actions as if you are using the throttle and stick as flying controls (gradually and watching for the response) not as simple bang bang 'selectors' of a new configuration (full power - selected) and attitude (tail up - selected)

[alanmt]

Mr Farley you are so right my Turbulent was only a handfull if you did not engage brain before any control was moved. Open the throttle slowly use feet to keep straight and let the tail come up when its ready and be prepared for a little more foot work. Enjoy the Turb just never go too slow over the hedge.
Alant

[angels one five]

When flying my Turbulent I always make sure that I start the T/O with the stick held firmly back in the navel base.
The same applies on a rolling start.
Stick back, throttle lever gently and smoothly forward, and as the speed builds allow the tail to come up by relaxing the back pressure. Try not raise the tail by pushing the stick forward of central.
The rudder is sensitive, so prompt and small corrections are the answer to unwanted changes of direction.

[kevmusic]

Thanks chaps - gently, gently does it seems to be the watchword. I'm always aware of the need to apply full throttle slowly, but I'll be more conscious of it next time. I'm up again on Thursday so I'll use the time in practise. I'll read through all these comments again before I go!

[OpenCirrus619]

Kev,

I always remember Glynn's favourite answer when the subject of "Which way does the nose of a Tiger Moth / Turb / Super Cub / .... swing when you ...." is raised.

The answer is "It doesn't - the pilot will have prevented it" :E

OC619