RC Slope Soaring
Dave Garwood
Guest writer Joe Chovan's guide to flying formation half-pipe maneuvers
FLYING FROM A HILL above Wilson Lake in Kansas, it warmed the cockles of my heart to hear someone behind me say, "You can tell when the Slope Dogs are here, because the half-pipes start."
A specialized Slope Soaring group activity we like to fly is a double stall-turn formation maneuver, called half-pipes after the skateboarding and snowboarding courses built in that shape. It's also called a Slope Scale Party, after Southern California's extreme fliers who developed the group technique with the legendary heavy, fast, warbird slope gliders.
Joe Chovan and I saw our first Slope Scale Party at Soar Utah 1995 and immediately wanted to join in. Starting in 1995 and in subsequent years I've been fortunate to have instruction and coaching from the best: Brian Laird, Paul Masura, Carl Maas, and Robert Cavazos.
During a Slope Scale Party at Los Banos, California, Inland Slope Rebel Mike Wofford commented, "The thing I like about this kind of flying is you don't know for sure that you will return from a mission—just like the real thing."
I find that half-pipe flying with a longtime wingman is one of the best grooves you can get in on a slope. Since it's exciting to watch, it attracts spectators, and generates questions on what it takes to fly this pattern in a group. We are fortunate to have Joe Chovan explain what is involved in his "Guide to Flying Formation Half-Pipe Maneuvers."
"What do the Blue Angels, Thunderbirds, Red Arrows, Snow Birds, and other air show teams have in common? Formation flying is a good answer. There's just something magical about two or more airplanes in tight formation that sends spirits soaring to the delight of both pilots and spectators.
"One of the signature aerobatic maneuvers seen during the PSS Fest [Power Scale Soaring] is the 'half-pipe,' which is when 10 or more planes fly formation U-shaped stall turns. This technique was developed and perfected by PSS fliers in Southern California well before the PSS Fest came into being.
"PSS Fest coordinator Brian Laird reflects how he and friend Paul Masura would spend hours each day shadowing each other in attempts to get the fastest dives and highest 'pumps' possible while maintaining a tight formation over the sea cliffs of Palos Verdes.
"On the slope, our chosen aerobats enjoy the lack of spinning propellers, which tend to damage powered planes venturing close to each other. While midair collisions are common among slope formation fliers, the relative speed between planes is small compared to the overall airspeed, which can approach 100 mph or more.
"Flying this way is not as dangerous to the planes as it may look to the casual observer because (when all is going well) they are traveling in the same direction and thus don't beat each other up when they do touch. In some instances, the planes will tend to "stick together" but often will separate with enough altitude for safe recovery. The result of these contacts is normally nothing more serious than swapped paint or scratches—which are often preserved as badges of accomplishment for some.
"The double stall-turn formation half-pipe maneuver takes all the planes from zero airspeed to max airspeed and back to zero airspeed repeatedly and when performed by several planes in tight formation, is an excellent way to allow groups of fliers to share the airspace—provided everyone knows how and demonstrates the ability to 'play nicely' together. Here are some tips for getting into and keeping the stall turns organized:
"1) First ask yourself if you're comfortable with the idea of flying in a group. Your skills should be advanced so you no longer have 'tunnel vision' for your own aircraft, and can widen the scope of your gaze to be able to concentrate on others in your field of view, while still maintaining control of your own plane. Another good test is to see if you are able to carry a conversation while flying (an activity common among formation fliers).
"2) Then ask yourself if you want to fly with a particular group of fliers (as might now be currently flying together on a slope). Is the group flying safely and not erratically? Are all pilots able to keep a rhythm and remain 'in sync?' If you're enticed to join, the answer is probably 'yes.'
"3) It helps to have planes of the same size and weight. Although not mandatory, 'syncing up' is much easier if everyone naturally gains and dispels kinetic energy at the same rate—and thus all the stall turns tend to happen at approximately the same time. You might ask participants what they are flying to get an idea which plane you should use to best stay in the rhythm of the group. Knowing exactly what to choose will come with experience.
"4) Before you throw your plane into the fray, wait for all planes to pass you so you won't throw directly into their paths. Have a plan where to fly so you can climb to gain altitude without getting in the way of the main group before you join in the formation. Often it's safe to dive to a side and head out front away from the 'pump zone,' flying side-to-side as you gain altitude, and staying clear of the group until you are close to the altitude the group reaches at the top of the stall turns.
"5) When you're ready to join, time your first dive so you will come very close to leading the pack. This will force everyone to see you and since you will probably have the least amount of energy in the group at this point, everyone should adapt to your pattern for the first few passes to aid your assimilation.
"6) The key to staying in sync is everyone must pump at the same time, no matter where you are, with one caveat: all planes should have passed 'show center.' If you are the leader, fly farther to the left or right and allow others to enter your field of view before you start your pump to fly vertical. When you think the last stragglers have passed center then you can start your rise.
"7) If you are the last to cross center, then look for the others to pump and that will be your signal for you to pump at the same time, even if you're not really close to the others. This will keep you in sync and avoid the dreaded head-on collision, which happens if you pump too late, and meet someone already coming down as you go up. Planes coming down have very little ability to steer out of your way because they have less airspeed, or worse, less time to react because they are going very fast, so it's up to you to pick your slot in which to rise so you won't be in anyone's way. Hopefully you pumped at the same time and you'll be clear.
"8) If you are consistently the last to cross center, you are probably the lightest. Your plane may not be as efficient and/or your technique could use some work. It's your job to fly inside everyone else and pick a clear route for your vertical rise. Unfortunately, if your technique does need work, you may not realize you are making things much harder for everyone else because they are always trying to avoid you on the way down (which is very scary and sometimes maddening if it happens with regularity). Learn to recognize this and plan an exit strategy if you can't seem to stay in sync.
"9) If you are consistently the first to cross center, you are probably the heaviest, and also pump the highest. You are fortunate to have energy to waste and you can make life easier for the others by 'feathering' your elevator so you don't go ballistic all at once, but save some maneuvering speed to steer around others on the way up (so not to crash into their tails as you pass them). With practice, you can match one or more planes consistently and maintain a tight formation.
"10) Performing the stall turn takes a lot of practice to master the art of 'not committing' all your speed at once when you trade your speed (at the bottom) for altitude by bumping your elevator. You want to always try to stop the plane from pointing completely vertical, leaving the nose pointed away from the slope face slightly (into the wind) so you can still steer. If you do not do this, you will be blown backward toward the hill and you will no longer be able to steer as part of the group. That is the first skill to master. Being able to steer within the rise of each vertical segment governs how well you can stay with your fellow fliers.
"11) The slower fliers (lighter planes or less efficient planes) will need to fly smaller U-shapes in the center. Don't try to chase the faster fliers by following their lines exactly. Conversely, the faster fliers fly much larger U-shapes. From the point of view of all standing at show center, it's a pleasing illusion that all planes are packed tightly together as they stay in sync.
"12) At the bottom of each U, everyone should be zooming past center at roughly the same time. The heavier/faster fliers should choose the lowest paths, and lightest fliers choose the highest paths so they will not cross. Whatever you do, take great care to make all corrections in this high speed portion of the pattern very slowly to maintain a smooth flight path. This minimizes the chance you will collide with someone by maintaining some separation with an easy-to-follow yet exciting course.
"13) When the planes do touch, the main thing to remember is not to panic and make wild maneuvers. Let the planes naturally separate, then let the nose drop into a down attitude. After gaining speed, pull out and guide your recovery. You must also check to make sure you have complete control of your aircraft, that no control authority is diminished. Always fly safely.
"If the planes are matched in type and weight, and the skills of all fliers are high, the formation will be very tight, and each set of 'pirouettes' at the top of the stall turns will happen in unison. This makes it much easier and the final effect is amazing—so much so that you may find yourself spending hours upon hours flying this way. If so, congratulations—you're hooked." MA
Sources:
Slope Aerobatics www.slopeaerobatics.com
Slope Scale flybyudan.blogspot.com
Leading Edge Gliders (785) 525-6263 www.LeadingEdgeGliders.com
Midwest Slope Challenge http://midwestslopechallenge.com
Southern California PSS Festival www.inlandsloperebels.com/pssfestival/festival.html
League of Silent Flight www.silentflight.org
Transcribed from original scans by AI. Minor OCR errors may remain.
