How to fly in Windy Weather.....
Thursday, March 20, 2003
WINDY WEATHER PLANES
All too often, on an otherwise nice, but windy day, folks just don't fly. Obviously, for a beginner, that's just common sense - but for someone who has some experience, the wind should just be another challenge to add some spice to their flying.
While its easy to see that experience level has a lot to do with how much wind is too much, it may not be quite as apparent that the type of plane you're flying also can have a great effect on your ability to handle winds. Let's go through a bunch of airplane design features and see which ones give us the best flying characteristics to handle winds and the resulting turbulence.
Size: In general, the larger the plane, everything else being equal, the better it will handle winds of all kinds; they just don't "flop around" as much!
Dihedral: The more dihedral in a planes wing, the more it is going to be affected by crosswind gusts; it is hard to keep the wings reasonably level, and therefore lineup to the runway is difficult in a crosswind situation.
Wing Loading: The higher the wing loading, the less a plane will be affected when hit with a gust.
Aspect Ratio: Lower aspect ratio (stubby) wings will be less bothered by gusts; there is less leverage for side forces to upset the plane, and the lower aspect ratio wing has a greater tolerance to changes in angle of attack caused by gusts.
Power: Pretty obvious - having the power to overcome the forces provided by the wind is a must. The same goes when you get into a sticky situation.
Lateral Control: Ailerons are very beneficial in a crosswind, in landing and takeoff phases. The ability to dip a wing into a crosswind without changing heading is essential, as is the ability to rudder the plane parallel to the runway heading while keeping wings level with aileron while landing.
Landing Gear: tri gear planes are easier to land and take off in a crosswind than taildraggers. And the wider the spread on the main gear, the better.
Manuverability: This ones a bit harder to quantify. You want a plane with stability, yet you do need good manuverability to cope with gusts. So you want a plane that is stable, yet responsive.
Wing Mounting: Generally, a low wing plane will handle crosswinds better. This is because the CG of the plane is nearer, in a vertical sense, to the aerodynamic center of the wing. So the low wing plane is not as easily rolled by a side gust. And by mounting the main landing gear on that low wing, we can spread them out wider.
It's unfortunate that almost every item above is in direct opposition to the characteristics found in a lot of popular trainers, the main exception being the requirement for tricycle landing gear. But even with trainers, there are differences; compare a Seniorita with the Cadet Mk2. While the Seniorita may be a bit slower and a bit easier to fly, the Cadet, with its ailerons, higher wing loading, lower aspect ratio, and lower dihedral, is a far better plane flying in windy conditions.
Going a step further with the same kit manufacturer, their Cougar(.40)/Cobra(.60 size) kits embody ALL the right characteristics for windy flying.
And in closing, I offer Confucious' only known saying about R/C flying - "To learn to fly in wind, one must fly in wind!".