3. Winds Aloft, Reverse Launch
This is the 3rd article in a series that will review step by step concepts concerning weather and flying pointers. If you're a new subscriber to the magazine you may want to order the previous 2 issues from the USHGA to stay on track with the flow of these articles. Get together with your local instructor and club to discuss these topics in greater detail. Be sure and expand your library of books and videos. This column will recommend certain books and videos, realize that there may be some ideas that are arguable. Practice the weather concepts daily, even when you aren't going flying. Begin to identify the trends that make for the best coastal flying, thermal conditions or exhaust heat sessions. Give your chums a call who flew on days you couldn't and see how close you can get to predicting the conditions. Be thoughtful about going to new areas and how powerful some atmospheric influences may be in contrast to your home sites. There are some sites that become unruly by 9am in August yet others that can be flown all day. Hire the local instructor to guide you when visiting new sites.
Be sure and study the actual soundings of the upper atmosphere prior to flying each day. These soundings are taken by the National Weather Service at 5pm and 5am throughout the U.S..This information can be found through a number of websites as well as through a phone call to Flight Service (1-800-WX-BRIEF). The www.paraglide.com website has a weather section that will lead you to a number of great weather information sources. Select the "Soaring Forecast" and choose the "complete report" for your area through 18,000 feet msl. You will see a few tables and a graph. Take a look a the wind direction and strength. Direction is given in compass headings (i.e. 0 or 360 degrees is North, 180 degrees is South). The wind strength is given in knots, a knot is 15% stronger than a m.p.h.. Your analysis is to determine if it is blowing too hard to fly at your local launch or if it might start blowing too hard at some point during the day. Air can layer itself horizontally throughout the atmosphere due to temperature, and thus be blowing at different intensities and directions at different altitudes. It's possible for there to be a "river" of air just a few 100 feet overhead or below your launch area that's blowing the opposite direction and more than you like.
On clear nights cool air can "puddle" up on the ground for 100's or 1000's of feet in depth. This is called an inversion. As you ascend from the ground through the lower atmosphere you will often find that the air actually gets warmer. This puddle of cool air is sitting underneath slightly warmer air and it's very possible that an uninformed pilot may not know that the winds above this layer are actually very strong. Different temperature layers of air don't mix - similar to oil and water. As the sun warms the ground the ground warms the air and the puddle of cool air warms up and mixes with the upper level "river" of air and within seconds you can find yourself in strong wind.
You will also find temperatures aloft information on the internet or through a call to Flight Service and this information helps us predict stability. We will discuss the thermal and lifted indexes in the next article.
The reverse launch gives a pilot far more control over the glider. When a glider is inflated in a reverse position it can be carefully examined for snags, knots, sticks and be adjusted to a symmetrical inflation very easily. When a glider is brought up in a reverse position the pilot has the ability to abort the launch much easier. Standing in the reverse position while waiting to launch is more sensible as well as you can more easily prevent the glider from getting the best of you in windy or gusty conditions.
The reverse launch is harder than a forward launch because you must rotate to a forward position without losing control of your glider, or your footing. It's the first launch technique you should learn, and take the time to learn it successfully before learning forward launches. The reverse launch can be mastered in no wind conditions as well as high wind conditions. Most people gravitate towards what's easiest and what they learned first, thus the reason for learning this technique first. Once the reverse launch is mastered the forward launch is a cinch to learn. Those pilots that have mastered the reverse launch may find themselves never doing a forward launch. Practice is the mother of skill.
Take your time learning each step of the reverse launch. Be sure and review the previous articles about how to hook-in to your glider in the reverse position. Let's start the exercises by leaving the control toggles, a.k.a. the "brakes", clipped in and out of the way. Become competent at raising the glider so that your right hand is controlling what you see as the right side of the glider and vice-versa with the left hand. Don't cross your hands.
Become completely proficient at bringing the glider up slightly and reaching for the "c/d" or "rear" risers. As your hands let go of the front risers you should swing your hands down and around with the palms up as you bring them up to the rear risers, this way you will find them more easily. Do this exercise 50 times and vary the point at which you let go of the front risers to reach for the rears. You need to develop perfect "body memory" of the riser positions. Begin learning to bring the glider up slightly crooked so you can move the glider laterally. Learn how to bring the glider up slightly and allow it to pull you downwind. This practice will be huge help to you in learning how to inflate your glider smoothly for every launch. This practice will also help you learn how to kite up a slope to your launch.
The next article will expand on the skill of learning the reverse launch. In the meantime, add the David Sollom book "Paragliding from Beginner to Cross Country" to your library. Review inversion topics in Pagen's "Understanding the Sky". Renner's book "Northwest Mountain Weather" is an interesting weather book. The videos "Starting Paragliding" and "Weather to Fly" are also excellent resources.