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Hello I'm new to float planes. I bought a used 90 size tiger moth with a saito 150FS with floats. The floats dont have a rudder. The previous owner said "its not needed for this airplane". Is that correct?

alasdair

Hi,
I rarely use a water rudder on floatplanes.
If there is very little wind they will turn using the air rudder.
Mostly, they will try to weathercock into wind. If the wind is strong the weathercocking tendancy overcomes any water rudder anyway.
Many models will overturn if you try to force them round a turn in a strong wind. It is safer to let them weathercock.
If the wind is onshore then take off straight into wind. Touch down straight into wind, cut the engine and let it drift back to shore.
If the wind is offshore, it is slightly more tricky as you have to put the model in the water and power up to fast taxi out (before it gets a chance to weathercock). Take off towards the shore (but not directly towards other people). Once airborne turn quickly away from the shore. Fast models can stand a little tailwind so if the wind is light you can take off downwind, away from yourself. Then touch down into wind,a safe distance out, and taxi into wind towards the shore.

Flying boats (and somelow wing monoplanes with floats)generally have better water handling and can stand being taxied in a stronger wind.

Turbine powered waterplanes do not have propwash over the air rudder so they need a water rudder.

scale only 4 me

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It comes down to personal preference, I use them when I can, a water rudder comes in handy for most airframes, but no, Not "necessary"

Approach Control

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Thanks for the info Alasdair and Scale only for me! Appreciate it. I will attending my first float fly this weekend.

Chip_Mull

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There are two types of taxying on floats, step taxying and displacement taxying. Displacement taxi is with the water rudder and the floats plowing like a destroyer. Step taxying is with a little power and on the step using the aircraft rudder for direction. Most aircraft will respond just fine using step taxying only. R/C models rarely have to dock or sail like a full scale plane requiring a water rudder. Most of the time we just plow into the beach.

Approach Control

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Thanks ChiP Mull. So At what point do I gradually increase full power or i dont take off on full power ? Or i just do a longer take off run?

Chip_Mull

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On take off there is a "sweetspot" on the floats. Too far forward and the front of the floats drag, too far aft and the heel of the floats drag. The sweetspot is where there is no drag and the aircraft accelerates. On a model, just apply full power until the plane comes up on the step and throttle back. It may take a few times to figure out if it's half throttle or quarter throttle but there is a place where it will taxy without taking off.

Approach Control

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Okay i will try that technique Chip Mull. Thanks again.

scale only 4 me

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A tigermoth has a pretty big rudder, you'll be fine off step too I'd bet

Approach Control

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Thanks agsin Scale only for Me. All u guys shared knowledge gives me more confidence on my first float plane flight.

JimCasey

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Here's some info about taxiing techniques.

Taxiing

Mikecam

I fly a GP cub off water and boy was my life made easier by installing a water rudder.

Otter Guy

i have a golberg cub, and a 6' beaver. life was, and would be impossible without water rudders. also step taxiing is a little risky. when i see most guys doing it they aren't truely on the step like full scale. with full scale, you pretty well never get the aircraft on step just to taxi, typically just to stretch out a landing roll to speed up getting to the dock. models dont have the same problem with overheating engines. but step taxiing is risky sometimes. you never turn around in any significant wind, just asking for trouble.

that link says to taxi downwind with the elevator up, that caused my cub to blow over, and i know a fella that lost a full scale cessna 170b that way. you get a gust under the tail and over she goes. neutral or down is the way to go. if you are plow taxiing to make the turn you need to have the elevator up to keep the nose as high as possible to get the wind acting on the nose as much as possible and give the water rudder some traction. once you pull the power off let go of the elevator. as was brought up earlier, sometimes if the plane wont turn, you shuldn't turn. full scale cubs have one rudder because if you had 2 you would be able to turn in winds that would turn you over more often than not. most of our models, even those reproducing larger heavier airplanes like beavers, behave more like cubs on the water.

real float flying takes lots of patients and a sometimes some creativity. less procedure and more technique than some kind of flying.

give your moth a try, see how it goes, it not hard to toss a rudder on later

Approach Control

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Thanks for th info. A beave is my next float plane.

Otter Guy

Beavers are sweet. ive only seen the unionville 6', and its not the best. very heavy and not very strong. could be modified easily enough. stronger spars and take some beef out of the nose construction and it would be really nice. the norseman was always popular at my old club