 Understanding Your Wing By Jim Slaton
A basic aerodynamic every pilot should understand is LIFT. Canopy pilots often relate lift only to the flare, because when we flare a canopy some air is deflected downward resulting in an upward motion of the wing. It’s important to understand that the wing itself produces lift. 
Wings are shaped so that air flows faster over the top of the wing than the bottom, creating lower pressure over the top of the wing, which lifts it. Hence, airspeed is crucial to performance. Larger wings with a bigger aerofoil cross-section create lift at much slower speeds, whereas smaller wings fly faster and need to maintain higher airspeeds to produce the necessary lift. All square parachutes require a certain amount of airspeed to generate the lift needed to fly and land. Larger wings with thicker aerofoil sections (accuracy & student type) land efficiently at slower speeds. Smaller, high performance canopies are inherently faster but require more airspeed to maintain their flight characteristics. So under some small, highly loaded canopies, pilots need to build and maintain a great deal of additional airspeed to land their wings efficiently. Canopies capable of flying at high wing loadings are not designed to be flown slowly. They can be landed with a straight-in approach but it is not always pretty and not always safe. Although smaller wings and higher wing loadings make canopies fly faster, they have less lifting ability at slower speeds and are very stall sensitive. Understanding this information you can see why skydivers who downsize too quickly are put in a dangerous situation. Skydivers who transition to some small, highly loaded, high performance canopies could be required to generate a great deal of additional airspeed on every jump to get productive landings. Added to this high-speed approach is the reality that not all landing areas – small DZs, off landings, demos, crowded areas – will be able to provide enough landing space. Most canopy pilots who downsize too quickly are not equipped to execute the approach required for an efficient landing. Consequently they get it wrong. Skydivers in this situation have two logical choices. If the canopy pilot is experienced enough to operate under the landing speeds required by the wing, they could be a good candidate for canopy coaching school. With proper instruction they can learn safe, airspeed-building approaches. But if the pilot does not have enough experience to perform more than a full flight approach or is uncomfortable with flying at higher airspeeds there is only one option, switch to a larger wing. Contrary to popular belief, hook turns are not required to land a high performance canopy. I strongly discourage sharp, snappy final turns to anyone considering this type of landing. Slow, carving, front riser approaches have proven to be not only the safest, but also the fastest and most efficient turns in high performance flight. The biggest misconception in high performance flight is that smaller, highly loaded canopies are faster so they swoop further. There is a point with semi-rigid wings where the performance starts to drop off. Each different wing type will have its own optimal wing loading. Operating at a parachute’s optimal wing loading gives the pilot the opportunity to get the most performance from their wing. Pilots who increase their wing loading above the canopy’s optimal loading will sacrifice a more efficient control range for speed. Experienced canopy pilots searching for better swoops should consider these important steps. First, operate as close to your canopy’s optimal wing loading as possible. Second, choose the type of canopy you think performs best at optimal. Last, don’t feel you have to downsize to get more performance from your canopy. The optimal wing loading for most of today’s high performance canopies is far too great for the average skydiver. Take the time to learn as much as you can about basic aerodynamics and the canopy in which you fly. Knowledge is power and power is performance. |
