Flying on Windy Days
One windy day flying my 120SR in the street in front of my house I made the mistake of flying it away from me downwind. It then got caught in a crosswind gust and drifted towards the house across the street. The wind hitting the front and of that house created an updraft and in the blink of an eye the 120SR was 100 feet in the air heading for some tall trees behind the house. Having no viable alternative I just cut the throttle and watched it drop out of sight behind the house. Fortunately it landed in a bush and I got away with just a lost link.

Flying on windy days is a challenge with the Blade fixed pitch models because flybar design limits how far forward the rotor will tilt with full forward stick and it can't keep the rotor angled down against the transitional lift generated by headwind. Once the rotor gets tilted up into the wind the only way to reduce the lift and keep it from soaring skyward is to cut power, but cutting it too much stops the rotors causing the model to fall out of the sky like a rock.

The trick to flying in wind is planning the flight path and learning to use the downwind legs to set-up the upwind ones. First and foremost you need to avoid getting the model downwind from your position, which can make it impossible to fly it back into the wind towards you. So on windy days find a place to fly where you can start off flying directly into the headwind with lots of wide open space ahead and to the sides of you. Flying upwind will show you immediately how effective normal elevator inputs will be at keeping the rotor disk tilted forward and always leave you a downwind bailout path that will bring the model back to where you are standing.

In windspeed up to about 10mph you should be able to make slow headway with full forward cyclic. Watch the attitude of the rotor disk relative to the horizon and keep it tilted down into the wind. Gusts of wind will create more transitional lift and pitch the rotor up and to the right. If forward momentum is stalled the only winning strategy it to turn tail and run.

A rotor disk pitched nose-up by a gust in the headwind despite holding the cyclic/elevator is exactly how you want the rotor oriented for an aggressive flight in the opposite direction. So instead of continuing the flight the headwind see the model pulled higher and higher by the transitional lift, just flip the nose around 180 with the rudder so the nose in now pointed nose down, keeping the cyclic forward. The stalled model will turn tail and and fly off like a scalded cat back towards you at speed up to 30 mph.

Speed is the key to any aggressive maneuver with a rotor craft and the speed of the downwind leg can be used to set up a second up-wind leg that works better than the first one from take-off. With the model heading back towards you full tilt you flare it to a stop by pulling back on the cyclic, setting up any other 180 flip turn. The more aggressively the model is flared to stop the downwind leg, the more it will be tilted forward to plow back into the wind once the tail if flipped. Pull cyclic back to flare, spin the tail, push cyclic forward and plow forward. The stabilizing flybar effect will kick in and start to level out the rotor again but before that happens you will be able to make some headway against the wind.

There will be quite a bit of vertical movement during the execution of the upwind and downwind legs so make sure the model is at least 10 feet in the air before trying this maneuver to avoid smacking into the ground on the downwind legs. Pay careful attention to the angle of the rotor disk. It takes very little forward tilt of the rotor to fly fast on the downwind legs and much more to make headway on the upwind legs.

Once the simple rudder flip turns are mastered try making clock-wise aileron turns at the end of a fast downwind legs. Pulling the cyclic to the right will flare the rotor sideways and start to pull it around like it was negotiating a banked curve instead of flaring straight up as with a cyclic-back elevator induced stall. As with the 180 flip turn it will be necessary to also move the rudder stick to the right to bring the tail around and point the nose in the opposite direction.

Shortening the ends rotor blades by 1/2" (10mm) will also help in wind by reducing the transitional lift. So if you break the tip off a rotor cut down the set and save it for windy days.

RC Helicopters
Flying Up The Learning Curve

This tutorial is copyrighted by © Charles E. Gardner.
It may be reproduced for personal use, and referenced by link, but please to not copy and post it to your site.

You can contact me at: Chuck Gardner

For other tutorials see the Tutorial Table of Contents