GPS navigational flying

An explanation of this competition class for gliders is best told by the person who brought it to the UK a couple of years ago and in his first world Championships came 2nd, and that is John Greenfield. An extract about this exciting form of model gliding together with a report of the World Championship competition can be found on John’s Team website at and more information can be found at

John has kindly made the telemetry kit needed to fly the course available so that others can try this form of flying and I will keep this page updated on how I and others get on having a go. I will also try and incorporate as many links to information and equipment for this up and coming sport as I can.
The below explanation of GPS triangle flying was taking from a more in depth article done by John for the
Scale Soaring Forum

John Greenfield


I suppose with a title like that I should first explain a bit about what GPS Triangle racing is all about.Simply put it is about flying large scale gliders around a triangular course where the turn points are not marked by pylons or flag men but by pre programmed GPS co ordinates. Each model is fitted with a GPS unit linked to a vario and transmits back to the ground via either the return channel of standard model radio telemetry or a stand alone system. The data is collected by specialist software running on a PDA or other device and displays the course, the models position on the course and as a bonus (and essential for racing) up to 40 parameters about the model, its glide angle, speed wind drift and a host of other data.

2 classes exist, the 1/3rd scale class where the model has to be a 1/3rd scale replica of an existing full size glider and the open class which as the name suggests can be any scale model up to a max weight of 25 kg. A sub category is an open model with a self launch capability.

The goal is to fly as many laps around the course as possible in 30 mins. Models are aerotowed to height and have to pass across a line at less than 500m altitude and at less than 120 kmh as verified by the GPS data. From that point the pilot is free to fly where he or she likes to find lift to complete as many laps as possible. The best current glider will only fly less than 4 laps in still air and will be on the ground in less than 15 mins so finding lift is essential for a good score. Tactics play a big part in reading the sky and deciding when to stop to look for lift and when to push on around the course.

e triangular course measures at 2.41km per lap with the first turn point 500m away from the start line. The second point is 500m at 90 deg to the start line and the third point 500m in the opposite direction to turn one. The course is always flown left hand and the turns have to be rounded in order. Rounded is not strictly correct as extending out from each turn point is 2 radiating lines each set at 45 deg forming a sector. A turn is considered to be taken if the model passes into this sector.

If at the end of the 30 min time period 2 or more models have the same number of laps then the model with the highest average speed is deemed to have won.

The class we can now entre because of changes in the rules starts from 2015

Glider Race Sport Class

The new Class starting 2015!

A non scale class for electric gliders will be introduced.
Following rules will be applied:

5.000 mm max. wing span
7.000 gr. max weight
75 g/dm2 max. wing load
Electric gear with a logger in between controller and motor in order to ensure a onetime motor run
Max. entrance hight 400 m
Distance 350 m (equivalent 1,7 km range)
Max. entrance speed 120 km/h

The link below will give all the information and more.

There are a few companies that supply equipment I will add as and when I find them.

The equipmentused by us this weekend was by Soaring Gadets

Because of the change it allows 4 and 5mtr sport gliders to entre so it encourages more people to get involved, you may ask how and why I have got involved with this next stage of rc gliding.
Me and Tony was given the chance to try the sports class with the
RC T3000 GPS triangle equipment, So on a nice carm Sunday on 18th of January we met John Greenfield over at our clubs site at the N.L.M.F.C .

20150118_102344 (FILEminimizer)

This is 9.30 in the morning and the few that come over are setting up, our glider's I am using for GPS Triangle Racing, the gliders me and Tony are using are the Simprop Prollution 4004 Electric.

20150118_102355 (FILEminimizer)

Once the equipment was fitted in to a spare channel in the reciever we were ready to give it a go, the ground unit was fitted with 2 ear pieces, so me and Tony could hear what the ground unit was saying, then Tony was telling me what I was ment to do and my next moves while John was explaining to my what the bleeps and other sounds and instructions ment.
After a while when doing the laps you start to see a triangle in the sky, you start to save lenght of flight per lap by turning as close to the triangle points in the sky, this will then also save lost of hight,on the first flight I did 11 laps in the 30 minutes allowed, but please remember when doing the race for real you must only use the power to get to hight, and must not use any more power afterwards until you have finished that race.
Because of the starting hight only being 1oomtrs the power was used to gain hight a few times in the flight so I we could get use to the equipment and practice .

One the second flight the cloud lifted a bit more and now I understood what I was hearing this flight was more relaxed but more competitive and you start tring to shave of distance to each of the 3 points in the sky and start looking for any lift and tryiing to stay up, on the last lap you try to do it in the fastest time possible so a dive to the finishing line ir required to finish in the quickest time with in the 30 minutes
This is because if the amount of laps are the same as the other flyers then the quickest time overall of the amount of laps done is used, if that is the same as others then its the fastest lap with in the laps done.
I must say the heart started to beat on the second flight on the final lap, and then you are hooked this time I did 13 laps.

Tony then had a go once again we both had the ear pieces in so I could understand the information I was hearing now I can see what its doing and showning on the ground unit, what the second person can do is give advice when to turn , this can make the differnce between winning and lossing I have been told
On this flight of Tony's he do 14 laps in the same time I did, but of course none of these laps count for real because motor was being used to keep up between flights.

This shows overall speed over the course there is a lot more that I haven't shown like going in to a thremal turn to gain lift it will tell you the amount of lift you gained and where the centre of the lift is and much much more, that I still don't know yet.
Thursday I sent a email to
to discuss the equipment with Bernie the owner who is a very nice and helpful person and goes that extra bit to help, I will be purchasing my equipment tomorrow and let you know more when i get it.

The equipment came in a couple of days, and after installing the in flight equipment in to the Prollution 4004 Electric I was ready to go, the first day out was Sunday 08/Feb , where I met John Greenfield bright and early at 9.30am cold and fresh but quite nice Sunday morning, The first thing we had to do was update the ground control with John's pre programed circuits from sites we might fly at, this is done by copying the micro sd card that is supplied with the ground equipment from Bernie of   From Johns equipment to my equipment, now all we have to do is set a switch up on the tranny to be able to arm the system to start the race, this would be the start and the finish line. The first flight was to see if making the new battery box for easy changing of the motors battery,
and to make sure the arming of the system works correctly
which it did, so I continued to do the 30 minute race but only training as I was getting use to the equipment and all the information that it gives you. So I would power up to 300mtrs as the sky was blue and could make it very hard to see plus the first turning point was right in to the sun, so max hight of 400mtrs was not yet met until later, this ment that once I came down to 50mtrs I would just power back up again to the same hight of 300mtrs until the 30minutes were up. and ready for a cup of tea and to understand more technical stragegy when in the air, on how the best entry to the start line and angles of flight to the turning points, After a cup of tea and choclate biscuits I started of real the racing, most of the races I was getting only 2 laps each time, with no lift at all to be found. John started to give me more tips to help allow more laps to be made while in the race to be able to save time and loss of hight, and to see the help I was being given work in front of my eyes, I could not believe how much there is to learn, this just made it even more interesting. I then started to get 3 laps in a race and catching thremals and when to best use them,
In total I did 10 races a couple had penalty points against me because the entry hight was just over 400mtrs, you can still fly the race but it wont be counted and can not be used in the competition, now I know this I will re arm the system and start again. After the days flying the race laps are entered on to a league website for the GPS Triangle racing sports class, more to this will follow shortly.

  After Last weeks flying the sun gave a little problem facing in to the sun with trying to see the ground unit
RC T3000, so a hood was required, that was this weeks little project.


Made from a plastic sheet from a folder at Tesco's for £1 and a Credit card size magnifier from Ebay for £2 ,the card was scored and folded in one piece and glued with evo stik, then a shoulder was made for the magnifier to sit against 20mm inside from the front edge and sealed with black silicone. but on my latest Futaba 14sg I have bought a clamping system.

Another good weekend at NLMFC Baldock with friends, John, Tony and Darren for some GPS Triangle racing, I did 13 races on Sunday over 6.5 hours with the best race was 4 laps, but was beaten by John that did 5 laps. I was very happy because all day I was getting 1,2 and 3 laps, but on the last race some thermals were found, that allowed me to get that extra lap, this made it even more fun because once you get use to the idea of the race and all the signals and sounds from the ear piece thats connected to the ground control unit the RC T3000, you can start to relax and start to look for thermals and start to use the wind and angles of the best way to get to the next turninv point with out lossing much hight, with all that you then start to play with the trims on the controls to aid the flight. All together 27 miles was covered in the 13 races that I did.
The new snoop worked great and made it easier look have quick glances of the ground unit, and help when facing the sun on the first leg of the Triangle course.

22nd March

Had a very good day this sunday a few races with 2 and 3 laps, but what happened next I was not exspecting after the last 3 races.
I was on the 4 race of the day started the race at 385mtrs after crossing the start line I started to feel lift and warm air started to come in, on the first 3 laps I was able to gain a little of some of what I lost each time during th first 3 laps.
So after 3 laps I was still at 330mtrs with only 50mtrs lost in height, then going a round turn point one for the fourth lap I turn of the triangle course to try and find some of the warm air that was passing through.
And this is what happend, after going up to 400mtrs I set of again gave some time for the thermal before setting of back on to the race, on lap 5 between turning point 2 and 3 I was back in to the thermal and gained more height up to 530mtrs I could have gone higher, but I tried to pull out of the thermal, what I didn't know untill afterwards that what I should have done was to put my nose down and speed around the course.
Because there will always be a cold front to follow a warm front so then I continued to complete the race and finished a total of 8 laps with 7 minutes left out of the 30 minutes given for the race.

This was the best racing day so far this year and hope there will be more to follow.