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Monday, February 23, 2009

E-Tsotsi sets new unofficial SA electric glider XC distance record

Some time ago Evan asked me if I would like to go to Volksrust in Feb as the MGA calendar showed only RES and Postal club competitions. Anyone who has done any slope flying before will think twice before declining an invitation like this. At work, Philip Otto also wanted to go and his intention was to take his whole family with.
In the above photo you can see the northern side of Tamatieberg in the background..

I had recently just finished my E-Tsotsi and knowing the conditions on Volksrust can be light, it was a sure selection to go with.
Lately there had been a lot of discussion on the MGA Chat group about South African Records. More research showed that there was no official XC electric glider record. So I decided to give it a go and try and establish a new SA Electric Cross Country glider record. I informed the MGA of my decision and they gave me the go ahead.

I had more than one course in mind and the one that I would use would depend on the wind on the day.
We arrived later than normal at Vloksrust at around 12PM, to find a nice NW wind blowing up the slope. Philip, Izak and Norbert were already having great fun.
I had one flight with my 2M CMP Omie and then did a test flight with my E-Tsotsi to confirm trim settings, CG and range. Everything work okay and I landed to recharge the lipo battery for the intended distance attempt.
Shortly before 4 PM the wind dropped and swung from NW to West. At this stage I realised that the conditions below the mountain on the flat field would be perfect for the XC attempt with plenty of daylight left to do the run.

We packed all our slope gliders first and left the E-Tsotsi to pack in last.
We descended the mountain to the start point.
Evan assembled the E-Tsotsi and at 5.51PM James Shaw my Spotter, Timer, Helper launched the electric E-Tsotsi on it way.

There was hardly any wind but while flying the course I could feel a slight crosswind from a westerly direction. This I countered with the rudder when needed. At this stage of the day I did not expect any major thermal activity and on my first glide down James informed me of birds circling straight ahead on my glide path. I opened the throttle for a brief run. The end result was that the E-Tsotsi shot up and must have gained 100 meter or more with only a 5 sec run without any circling. This gave me at least a 7 km of distance gain.

Meanwhile, Evan settled down to a steady 45 kph with the Garmen GPS displaying the actual and average speed as well as distance traveled. Behind me Robyn, James girlfriend, was taking pictures as we moved along. Above us slightly to the left the E-Tsotsi was flying like it was on rails. I can only attribute this to the fact that the air was very stable and smooth (Charl describes it as “Campaign air”)

Every time, after a motor run, the E-Tsotsi would decent to a certain height and then, as if was floating on a cushion of air, would maintain height refusing to come down.
It was this conditions, plus the lack of sink that made the kilos go by and never did I once circle to try and find lift.

Evan Assembles the E-Tsotsi

James about to launch the E-Tsotsi

Above and slightly to the left.

James scanning ahead for any lift or obstacles.
Just after a motor run. Nice and high.

Amersfoort - Straight ahead

Evan driving - Nice paved tar surface all the way.

Me, craning my neck out the side of the Kombi.

Plenty of landing along the way.

It was not long before we passed our intended landing point of 25 kilometers.

James checking the GPS

With the conditions being very good, I decided to carry on and 6 km later flew past the town of Amersfoort. Unfortunately, 4km after Amersfoort we were forced to came to grinding halt, with a Stop/Go traffic control not in our favor. I got out of the Kombi and circled overhead while waiting for the light to go green. After a while I had to make the decision to end the flight as I had no telemetry equipment on board and could only tell from the last motor run that the battery pack was nearing the end of it's charge. (Never mind the fact that any cars approaching from behind would not appreciate the fact that we would be crawling along at 45 kph on the narrows single lane)
Circling overhead
The landing presented no problems and just under a hour after take off, much to the delight of all the occupants of the cars that lined up behind us, I landed the Tsotsi in a field next to the road.

Nice big landing field
On approach

The whole team shook hands and while Evan and I recorded the GPS information, James and Robyn dismantled the E-Tostsi. All the relevant information will now be forwarded to The MGA for ratification and acceptance of the attempt.
GPS data

As we returned to Oom Louis place I saw a typical sun set scene that just put the cherry on top of the cake of a really flawless flight and just a great team effort.

Only, on the way back did I realise how far this little 2 meter plane has gone.

To Evan, James, Robyn (for all the lovely photos) and Kayleigh (for refreshments) a big thank you for assisting me with this flight. You all are definitely on my list for the next attempt.

For the Record

Distance flown in a Straight Line: 35.1 km
Distance traveled by road: 36.3 km
Time: 53 min 59 sec
Moving average by road 43,1 kph
6 Motor runs
Total accumulative Motor Run Time: 5min 59sec
GPS data
Start point: S 27,17.117 E 29,53,786
End Point: S 26,58,16,7 E 29,51,502
Equipment used
Battery: Lipo 2100 maH 3 cell(11Volts)
Scorpion brushless motor 550 watts
Scorpion Speed Control 35A
Prop: Graupner thin electric folding prop 13X7
2xGWS servos 1.3 kg
Rx: JR 770RS
TX: 9x2

Tostsi Airframe Data

Wing span: 2meter

44.16 sq dm

Total weight 1080 grams
Wing loading 24 gms/sq dm
Aspect Ratio 9.24
Designed by Evan Shaw 2003.


Izak Theron said...

Knap gedaan Piet!

Tigger said...

Pragtig Piet!

Evan Shaw said...

"Skote Petors. Did kind se naam is al weer Wit Willem" Or something like that?
Well done Piet.

Anonymous said...

Pieta, check hierdie ou! hy het 164km gevlieg met 'n F5 model:,,

Piet Rheeders said...

Hi Gert,
Ek het dit gelees to ek gesoek het vir meer informasie. Dink jy ons kan die werld record aanpak. Ek soek nou vir meer kapasityd batterye. Het jy enige idees?