What is this you might say... You are hearing it here first on VTPR Aerobatics:
November 13, 2018

Inspired by French RC glider pilots, VTPR type of aerobatic flying is primarily performed at flying sites having a gradual to semi-steep rounded slope. Ocean front sand dunes to cliff topography are popular sites as well as inland slopes that have a wind direction perpendicular to the slope face. Wind carries up and over the slope face creating a lift zone in front of and above the slope lip or edge at top. This lift zone is where the glider pilot fly's the glider in all manner of aerobatics and style he chooses while managing kinetic energy appropriate to his model.

Traditional slope and French VTPR aerobatics has been around since the 1960's with many forms and styles. We have come to realize in 2018 there is another little known and seldom performed VTPR type of aerobatics. And even that only in part at the moment. We are coining it "PARK-VTPR". This exciting type of VTPR flying will be performed on flatland sites such as beaches, parks and fields where there is no slope in sight! And the same French style rules apply meaning, the glider performs aerobatics within two wingspans from the ground to touching the ground! So the obvious question is, "How does the glider stay aloft without lift?"

Enter the purpose designed and built motorized VTPR glider (MVG). Here is an example video that expresses the MVG glider dedicated to 2.5 meter glider planform. Its a modified Excalibur with an electric motor. Traditional slope aerobatic model builders and pilots may balk at the idea of mounting a motor onto their prized machine, but nothing ventured is nothing gained in RC glider modeling. We have great respect for all slope aerobatic modelers whatever their preference around the globe. We believe its a good thing to add new dimensions to the already very popular sport of glider aerobatics.

video courtesy laploz

As you can see, this opens up many more possibilities in VTPR type of aerobatics. What are some of the perks of flying PARK-VTPR?

1) Drive time to the flying site is within minutes of home.
2) Climbing steep and sometimes dangerous mountain trails to fly goes away. Great news for elderly pilots.
3) You can load up many planes and gear in the car and leave it until needed. Just walk back a few steps to the car and get it.
4) Wind is no longer necessary to fly. Timing or waiting for good slope wind direction is eliminated allowing the pilot to fly nearly everyday.
5) Flying can be performed in glass-like air, something slope flyers crave in late afternoon hours as the sun sets.
6) Night flying is also possible in glass-like air.
7) Searching for your downed glider in the bush down the slope and having to climb back up goes away.
8) Flying on beaches before noon or late afternoons adds a natural dimension to the experience having background wave water ambiance.
9)  To experience the ultimate in RC glider aerobatics mixed with danger and beauty up close.
10) And finally, you can bring family, the kids and friends and have a picnic atmosphere while flying. Nothing like a cheer leading group edging you on to daring and fun VTPR. The French do this on a regular basis on camp outs.

Video courtesy JBs Flying Page

This video of Julian Benz and his Xplorer 3 in certain sections demonstrates the concept of low and slow PARK-VTPR flying with motor assist. With the design of a very light air frame and on-demand electric propulsion, one can only imagine the many low & slow possibilities. Granted it will be more dangerous because the slope pilot can no longer rely on upward slope lift as he is accustomed to. 3D pilots will easily catch on. The left stick now becomes the main input that determines just how low and slow one can safely execute and maintain a controllable aloft state!

In this video, JB is demonstrating a small fly box of air very close to the ground as we like with PARK-VTPR. Note the slow circle and a tip touch exactly at 3:02 of the video. Its absolutely beautiful skill on the sticks and with that, we can see the possibilities are wide open in the park. Particularly everything you see done here, but in the inverted flight mode which even the great Julian Benz hasn't yet ventured!

Now we just need a purpose built glider designed for ease of aerobatics both right side up, inverted and all points between. We call these new types of machines MVG's (motorized VTPR glider). More details on a model being designed called VeLectro in the near future.

As of this writing the MVG is based on a 2.8 meter planform. The AUW (all up weight) is designed to be between 1300 to 1400 grams. That is 7.0 to 8.0 ounce wing loading range depending on aspect ratio chosen. Airfoils can be the traditional SB96V/VS, the TP42/TP29/TP66/SC17 and or a symmetrical home-brew airfoil. Due to the extra lightweight in calm air, there is no need for a four servo wing. Snap-flaps are still an important mix on 2/3 span ailerons but this simplifies the build and minimizes critical weight. Target weight of wing half panels should be in the range of 255 - 340 grams flight ready. This requires great attention to light building techniques and materials.

Fuselage and feathers group need to be in the range of 500-540 grams fully loaded. What this means is we no longer need the typical tall aerobatic fuselage at the wing leading edge and forward. Again, there is no slope lift nor high speeds necessitating the fish-like fuse profile. We can now utilize extra light F3J style fuselage and feathers greatly reducing weight.

This is the concept of PARK-VTPR, and it appears to be a viable and very exciting flying type for those so inclined to the ultimate adrenaline rush even more than traditional VTPR. Both types are amazing to fly, PVTPR just adds a whole new dimension in the sport of glider aerobatics.... E

VeLectro 2.8 mvg build thread here

Stay tuned for announcements of new PVTPR flights as they are 
flown and recorded...

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