Welcome to the exciting world of Slope VTPR Aerobatics. What does VTPR stand for? In French, 'voltige tres pres du relief' or aerobatics very close to the terrain. How close? Ground '0' close! We are proud since 2009 to be the first Blog dedicated 100% to VTPR style of aerobatics. Enjoy one of the most exciting forms of RC glider aerobatics in the world right here!
Most scenesaresnuffonaslope behindthe Menez-BICHEM (camping Pentrez). The slope isfacing south-west andthe viewis superb(and more is a fieldofcorn!) Weare wellventedthat day. Judge for yourself! Man oh man what FUN!!! AAA+
One of GODS creative designs from which ALL models fall short... A tip dragging Albatross!
The wingspans of the largest great albatrosses (genus Diomedea) are the largest of any bird, exceeding 340 cm (11.2 ft), although the other species' wingspans are considerably smaller (1.75 m (5.7 ft)).The wings are stiff and cambered, with thickened streamlined leading edges. Albatrosses travel huge distances with two techniques used by many long-winged seabirds, dynamic soaring and slope soaring. Dynamic soaring involves repeatedly rising into wind and descending downwind thus gaining energy from the vertical wind gradient. Slope soaring uses the rising air on the windward side of large waves. Albatross have high glide ratios, around 22:1 to 23:1, meaning that for every metre they drop, they can travel forward 22 metres.They are aided in soaring by a shoulder-lock, a sheet of tendon that locks the wing when fully extended, allowing the wing to be kept outstretched without any muscle expenditure, a morphological adaptation they share with the giant petrels. (source wikipedia)
The graphic layouts shown give those new to VTPR Aerobatics a rudimentary idea of the playing field. It tries to focus the plane orientation to the slope and every slope topography is different. The arena would need to be laid out as needed to gain the best advantage of the prevailing wind conditions the day of. Pilot box could also be situated in a way that the pilot prefers to see his plane through the arena. In a competition the pilot box may be more strictly located by the referee. You'll note the four corner poles. These define the minimum height level from the ground which so far seems to be best set at 10 feet. These are used as pilot sights or gauges. The goal in VTPR is to place the model as close to the deck as possible without crashing.
The 10ft maximim height rule and below is the established Vtpr performing "sweet spot". It also allows some headroom to ease into the 0-6 foot "danger zone" within the arena or can be used as a comfort zone height. Typically there would be no penalty for flying outside the fly-box perimeter. Vtpr by nature is very unpredictable in it's windage and lift conditions requiring the pilot to constantly adjust his flight path to maintain proper model momentum throughout the run or heat.
Another really nice VTPR practice session by "Awesome Dawson" Henderson out of Flagstaff AZ. He's sporting his heavy Le Fish getting low, ground "0" low for you sports fans! Add a few more pounds to her D and you'll be able to make some money digging ditches LOL...
Yvain (aka Le.Frog) is a most interesting and a very talented pilot/performer, one of the best I have seen from France. His video Drawings in the Sand is superb and to this author probably the best representation of true artistic VTPR flying that embodies all the elements necessary to take the gold! The music, the lighting and seascape combined with beautiful flowing lines flying his Le Fish in a small fly box is what is simply called a masterpiece, nothing better. Thank you Yvain for your wonderful VTPR interpretation of Drawings in the Sand, we look forward to more of your artistic works of VTPR beauty...
This video is considered the all time standard bearer in French VTPR aerobatics. Contained in this post is a time line of notable sequences worth observing closely. There is a lot to learn watching Rémi Lebesque and Eric Poulain in this 6 year old masterpiece of low glider aerobatics. Enjoy the flight!
0:00 signature French roll on launch - EP
2:30 radical low left roll
3:13 graceful left deck flip
3:33 low deck rolls fast and slow
4:29 low left flip to inverted low pass
4:45 continuous low right rolls going left
5:05 touch & go into low left flip off deck
5:19 another touch & go to right hand flip off deck
5:56 falling knife edge going left into an outside right turn
6:44 low pass into multiple flip rolls
7:01 low outside right turn and more great low passes
7:45 low left pass into multiple hovering flip rolls
9:15 multiple hover rolls
9:40 knife edge going right
10:10 another French roll on launch - Remi
10:46 slow left pass into slow off-camber floating rolls
12:00 low deck rolls
12:38 overland low pass into deck rolls up front
13:13 low left inverted pass into a right flip roll
13:20 beautiful low pass into an off-camber floating left roll
13:30 and my favorite, inverted overland slow pass into the wind to a flip roll out front, all overland!
A periodical overview of the sports path and progress in the US.
·"But more what we call in France VTPR "Voltige très près du reflief" (translation: aerobatics very close to the ground); this is a very spectacular type of aerobatics that requires very good skills and no fear". Pierre’ Rondel, 2005.
·Specifically "any aerobatic maneuver, figure or trick interpreted by the pilot that is performed successfully and in whole directly above the ground at any desired air speed within one half to one wingspan height above the ground”. Eric Johnson, 2011.
2011 marked a banner break out year of VTPR conversation and flying in the United States, specifically Southern/Mid California. This author in conjunction with fellow VTPR enthusiasts organized an all day VTPR fun-fly meeting that resulted in much progress on the slope and new model designs we now see in 2012. The idea was to explore and expose this little known fun style of aerobatic slope flying and to spur new conversation on modeling design for the sport. These two goals have been met and are on a growth path never seen before in many years. Thanks to the dedication of a few core enthusiasts of which I will name for posterity VTPR is experiencing new life and vigor in the states though it is still ever so slow. They are “CptMike” Ball, Paige “FSD” Anderson, Steve “Surfimp” Lange, “Awesome” Dawson Henderson, “Swiss” Peter and yours truly Eric “Oldscooler” Johnson.
Some long term goals now include the continuance of organized VTPR fun-fly events and the possibility of an official VTPR Cup Challenge spectator event with real prizes. And in the grand scheme it is hoped VTPR may be able to offer an official AMA sanctioned event for those inclined to compete. Currently the core group is having conversations exploring ideas to eventually come up with a VTPR event format with regards to pilot classifications, model types, scored compulsory and freestyle heat flights and overall event organization. All of this in a package that promotes FUN for which the sport was originally intended. Through these conversations and web postings we are finding out there is a wide disparity of opinions on the subject of competition. Some welcome the format and some flatly refuse to be a part. This is nothing new as every favorite fun pastime whether its potato sack racing or pitching horseshoes has their supporters and detractors when competition speak enters. In the end if fun is nurtured and remains the prime goal it is believed even a VTPR competition can offer slope soaring enthusiasts a great day on the hill.
There seems to be two classes of thought or styles of VTPR flying within the group and at large. One group which probably consist of larger numbers enjoy the smaller sized and ultra lightweight models. These types of models are usually sized from 48-68” wingspan, fly at slower speeds and offer a very active and crazy style of VTPR aerobatics. This includes flips and flops and all sorts of gyrations that can at times become difficult to follow as a spectator but it looks like the pilots are enjoying themselves immensely. Fun is definitely being promoted in this demographic.
Then there are pilots that prefer larger more majestic flying models that range from 80” wingspan and above. These models perform figures in a much more smooth and precise manner that can fly at lower speeds but can also perform very close to the ground maneuvers at higher speeds making this group a bit more daring and dangerous to the model. These larger models can get expensive with many hours of labor to construct. Needless to say even with all the risk fun is still the core reason this type of flyer can’t wait to get to the slope whenever he can.
With these two classes of flyers in mind it is a known fact that both are excited for either class to see each other perform their style of VTPR. There have been many disagreements and opinions leading up to today that would suggest there is only one way to perform VTPR aerobatics. This according to this writer is nothing further from the truth. As long as the primary definition stated above is met then however a performance is presented is solely up to the individual pilot. If there are compulsory maneuvers required in the event then that is a different story. But freestyle VTPR is open game and should be promoted to its fullest for the betterment of the sport. You’ll know it when you see it. This poses a daunting task in the points awarding department but its believed a simple and acceptable event format will be developed this year.
In VTPR style there aren’t many if any models on the shelf for the consumer to purchase and build as one would normally think. Most require obtaining a set of plans and “scratch building” to suit. This means VTPR modelers are usually above average builders that enjoy tinkering and adjusting for maximum ease of performing figures close to the ground. After all in VTPR the ground is your friend and frequently visited to maintain that friendship. Model survivability is paramount in VTPR.
Light weight low mass EPP (foamy) and Wooden (crunchy) models are being developed in the US to maintain this ground to plane friendship. Such planes as the Swiss Fish, Leviathon, Zeppelin, Big Fish LW, Stiction, Vol-Lent, Whale, Foiler 2.5, Axis 72 and other PSP models to name a few. Also it is hoped a “spec plane” will be developed that will be a dedicated One-Class event competition model of exacting specifications. Who will be the designer/supplier of this unique new design is currently up for grabs. If you’re interested please let it be known.
Every sport even in RC slope soaring have their slope of slopes that people will travel long distances or plan a vacation around just to fly it. One that comes to mind for the led sleders is Point Fermin. Another for the PSS group is Cajon Pass. Then for general slope soaring of all types of models is Torrey Pines. For the DS group, Parker Mountain. All soaring groups have that one slope they adore and dream of flying someday. In California a search is underway to find the “Mecca Slope” to perform the best possible VTPR in the most desirable wind conditions. One so far comes to mind and that is Marshall Peak slope in San Bernardino, CA., up highway 18 towards Crestline. Another one could possibly be Grass Mountain though the drive we hear can be treacherous. The hunt is still on and will be posted as soon as the gem of a slope is located.
All in all a terrific jump start year in VTPR. We hope you climb aboard in 2012!
Profile Slope Planes are beginning to show some promise for the future of slope VTPR aerobatics though it’s a slow pace in the big bad world of “foamy” glidering. Since I introduced the concept in 2011 with the launching of the prototype ZEPPELIN above, there is an interest of getting back to wood construction techniques. I am seeing a few projects across the globe of modelers designing their version of a PSP, and that gives me great delight. Wood is here to stay folks, no doubt about it. Balsa wood is an amazing thing if one can understand just how wide its capabilities are in a glider design. And since I am primarily involved with the rough and tumble world of VTPR aerobatics, this is especially true. There is naturally great apprehension in light of foamy durability to building a woody type “crunchy” model which at first, even I was skeptical. But my love for building crafty things beyond just glider models guided me to move forward and come up with something with greater durability and flying performance that could attempt to re-energize wooden modeling and have fun doing it.
Originally, the primary thoughts in designing a wood based VTPR glider was that it needed to be a tool, a model one could go out and not worry about its beautiful cover getting marred up. Something the pilot could use without limit to hone his skills, have fun and be easy and inexpensive to build. It needed to be a two piece unit sized in a popular wingspan, and it needed to be very lightweight and durable. A daunting task in wood for sure. The span size chosen was 68” (1.7m) and the target weight was 25-28oz equaling a 7.5oz wing loading. Secondly, the idea was to be able to fly slow and low yet have an efficient wing to be able to zoom back to a good manageable kinetic energy state to be able to cleanly set up for the next aerobatic figure with confidence. It is very important that the VTPR pilot once he enters below 72” off the deck in all manner of aerobatics whether it be inverted or slow rolls and such, he or she needs to know his craft is going to perform, and with ease. So I went with a true airfoil 100% of the chord length not using the typical aileron stock we see in generic wing construction. The airfoil of choice by Sarge Barth is his SB96V/VS, but with a modification I chose for a little bit more efficiency at 7.5oz WL.
The fuselage construction had to be very simple for the average modeler. Using 1/4” balsa stock in a 3 layer ply arrangement turned out to be a promising design given the total “low mass” of the model. Granted, balsa wood will never be as durable as EPP foam. But I found that once the design enters sub 30oz in the 1.7m span range we have something much different than the conventional age old wooden box fuselage design. The plywood balsa fuse plank becomes quite formidable yet is very lightweight. Another primary reason for going with a plank fuselage was to save weight and complexity in assembly. I wanted something that if crashed hard, and a broken tail boom was the result, the modeler could repair in the field or on the bench in 30 minutes. He wouldn’t need to reconstruct a box anymore. And as it so happens during deliberate testing this occurred a few times and it’s pretty cool to see the repairs went quite easily and quickly. Ultimately we want to fly unabated of any fear of breakage but as mentioned above, this concept is a leap forward in the wooden RC world when it comes to durability. It takes a lot of abuse having a low mass component. The more I fly the design the confidence level grows exponentially similar to flying a foamy.
Next and I think I’m one of the first in slope VTPR to do this, all the radio and servo gear is mounted externally on the fuselage open to the elements. At first one might think, “that’s not going to last, it’s going to get banged up”. This isn’t the case. After many hours of field testing deliberately crashing the prototype PSP there were no effects to the gear. That is unless you enjoy flying in the rain or plow into a tree or the ground at full speed. It’s quite amazing and that’s good news. The open design has a couple nice features. Ease of maintenance on the gear, and the protruding gear doesn’t increase any noticeable degree of parasitic drag. These PSP’s fly slow and low VTPR and are designed for sub 25 mph air speeds but they accelerate from 0 to 25 very quickly due to their efficiency. The flyer who normally enjoys big and fast aerobatics won’t be thrilled about this PSP design once he experiences the lagging high speed he might normally enjoy. He will be forced to fly in closer proximity to himself or land it and fly something else. These are purpose built machines that will deliver maximum performance for which they are designed, nothing more.
Lastly, my PSP’s being a two piece design are easily transportable and incorporate the tried and true rubber band wing mounting system. This feature is very effective in saving the wing and fuselage. I have deliberately crashed the model with no breakages in the wing saddle area of the model. It simply twists on the center axis of the wing or pops off on a hard ground hit. I usually install 4 rubber bands. They are rugged performers and are not intended to look totally awesome unless you really enjoy the more mechanical looks of a machine over sleek and beautiful lines. They won’t win a beauty contest but they get a lot of looks on the slope. It is true some most slope pilots generally have to like what their bird of choice looks like to help him fly better and prouder. My thought about this though pales to the performance beauty these little wood models can produce. I find that experiencing flying an economical, a little unique looking and aerobatically efficient model in VTPR mode is quite an exciting thing to experience. Performance beauty IMO trumps external beauty any day. I hope some of you reading this will try wood building again in a new light of understanding that I have shared here over the old fashioned way of box building. You could be positively surprised and encouraged of the results.
If you need any assistance feel free to contact me.
Good Lift… Eric
PS: As of this writing the second in the PSP line called STICTIONis now in the air flying beautifully below ;)
Francois Cahour developed this original 2.5m VTPR planform. This premier model is not a production unit, it is probably the single model that later inspired the great Excalibur and Sonic models over 25 years ago! The model was ahead of its time and continues to perform on the cutting edge of VTPR. Thank you Francois for leading the way and your contribution.
Francois review of the model can be read herebut you will need to translate.
When I first viewed this video of Cody Remington maneuvering his Espada-R moldie it took my breath away. Then the more I looked at it I realized maybe this is an American version of VTPR with its daring in your face flying style and he makes it look so easy. This is pure skill and he's such a young man. Oh and by the way he's a member of the US F3J Soaring team who has already amassed many awards and competition wins in his quiver!
Another fantastic display of VTPR beauty performed by William the Great! Thanks to Pierre Rondel of Planet Soaring this was filmed. Another early influence on this writer that has driven me to build the rare Breton Sonic and I'm glad I did. Through many conversations with the elder Michel Leroyer Guillaumes father we were successful building the ships. I owe a great debt of gratitude to the Leroyer family for their assistance. I hope you enjoy this incredible talent as he shows us how it should be done. The Standard...
Some new VTPR action with two very rare SONIC 2.5m models last weekend. Weather finally turned around this new SoCal season to greet us with the first real aerobatic outing on these majestic ships. I found the Sonic to be very friendly and just a joy to fly in full confidence. Stay tuned for more outings Sonic style.
This model is an evolution of the famous Quartz of François Cahour. The design of the airframe is more modern and presents a lesser trail. Sonic has existed since 1997 and revolutionized the world of stunt flying in the same capacity as Excalibur in thefts VTPR. In effect, it allows a definite and academical piloting for those who want it but he also excels when it is a question of producing completely removed and deranged faces. David has said himself, "The plane was not an idea but an evolution". Since they found nothing valid in epoch in trade and that the style of "Breton" theft was really a bit special, the idea was simply to have a glider adapted in the lead and in all craziness which they could imagine!
Sonic is considered to be the glider of stunt flying par excellence. Its qualities of theft and its low weight allow it to be agile in all weather conditions. It enters extreme performance in no time after launch and enters very well in strong weather conditions. This model will enrapture all keen pilots of modern stunt flying or not.
By permission, Michel Leroyer, Guillaume Leroyer, 2010
The video was put together on a sunny afternoon over at CptMike’s place once the pair of birds were completed. It was a very exciting day to be able after months of planning and building these ships to see the culmination of a fabulous project between longtime friends come to fruition. I don’t know about you but I enjoy the process of a build project as much and sometimes more than actually flying them. This especially holds true when it’s a difficult build to make all the pieces of information and parts come together from across the globe when there are no free sources. Dedication and commitment and the desire to own one of the best aerobatic models ever produced were the driving forces on this one. And of equal importance was the continued strengthening of our friendship through the process. Sure we had disagreements and many questions needed attention but through it all Mike and I both have one great ship in our quivers. To sum up, this plane is gonna be a lot of fun flying now. Can’t wait to explore more VTPR action with my new friend…
In case your curious what a Sonic looks like bare naked check this out. Lightweight FG Breton fuselage, veneer balsa white foam core wing panels, carbon fiber canopy. A recipe for many doses of VTPR fun!
Your going to be hearing a lot about the 2.5 Sonic here. Guillaume (William) Leroyer is one of the worlds best VTPR pilots from France. It was he and his trusty blue flame Sonic that inspired me to get into the sport. In this ocean front video we can see just how incredible a pilot Guillaume is handling very low lift conditions like the pro he is... Fabulous!