Let’s see a show of hands here. How many of you have become amateur meteorologists since you learned to fly model airplanes? Yeah; me too. It seems as if I always have my eye on the treetops looking for calm conditions that will allow me a quick flight here or there. I’ve gone as far as programming several weather websites into my cell phone for a quicker reference! It’s amazing just how much even light breezes affect the smaller and lighter models we commonly use for RC flight training. This month, I focus on understanding the effects of wind on our models, and I suggest techniques to handle breezes.
ESTIMATING WIND SPEED
Weâ€™ve all heard the local RC expert claiming he flew his stock Slow Stick in 20mph wind that gusted to 30. Well, unless he checked it with an anemometer, donâ€™t believe him. ? Well, itâ€™s strong enough to raise all our eyebrows on the flight line, even when Iâ€™m flying my 130, 000- pound Boeing jet. I think that most modelers dramatically overestimate wind speed, not so much in an attempt to impress, but more because they lack perspective.
This lack of perspective isnâ€™t surprising because U.S. weather observations give wind speed in knots and miles per hour, and it isnâ€™t easy to wrap our heads around those numbers. A wind of 39 to 54mph is a â€œgale, â€ 12.65 to 18.4mph is a â€œmoderate breeze, â€ and 8 to 11.5mph is a â€œgentle breeze.â€ The upper limit of a â€œbreezeâ€ is 31mph. Any higher, and weâ€™re flying in wind!
To help us estimate wind speed, letâ€™s use simple math to convert miles per hour (mph) into feet per second (fps)â€”a unit we can more easily â€œseeâ€ and estimate.
The numbers in this simple table will make it a lot easier for you to estimate wind speed. You can decide for yourself whether the degree of error caused by rounding off the actual fps number to the nearest 1/2 (.5) is important to you.