Phoenix 2400- 2 hour flight with thermals and vario
Interesting highlights from the flight:
Finding a thermal at 30 metres: 14:10
Climbing in a super-strong thermal (watch the altitude increase!): 1:40:52
This video contains the raw full length of HD footage taken from a recent flight I had with my Phoenix 2400 model plane. Skip to 5:02 and onwards for pure soaring. The flight was undertaken from some fields surrounding my home village in South Somerset, England. The flight took place on the 29th of July 2020, where I took off at twenty minutes past one and flew for two hours and twelve minutes, using a single 2700mAh 3s LiPo battery and strong assistance from several thermals.
The HD footage was taken using a RunCam Split 3 Nano camera. During these flights, the plane was flown mostly FPV, and contains a flight controller running ArduPlane firmware.
Overlayed on the footage is some of the flight data telemetry logged by the RC controller. This data is saved as a CSV file. I then used the software 'Dashware' to overlay the data onto the HD footage, with help from a video tutorial and template from SnappyFPV: • Tutorial: OpenTX Logs in Dashware | Teleme...
The audio on this video is the sound that would be produced by a variometer, using verticle speed data from the model aeroplane. A variometer (or vario for short) is a flight instrument that is used to inform the pilot of the rate of descent or climb.
I wrote a program in MATLAB, which takes in the verticle speed CSV data logged by the radio, and generates a series of 1 second WAV files. Each of these WAV files is made up of a chirp wave modulated with a low-frequency square wave. The starting and ending frequency of the chirp and the frequency of the square wave are both varied depending on the previous and current verticle speed. The starting and ending phases of all these waves are aligned to ensure a smooth sound. These WAV files generated by MATLAB are then stitched together using Adobe Audition and synchronised with the footage.
With the good weather we've had recently, I have been enjoying a lot of thermal chasing. Monitoring the verticle speed of the glider, circling in rising columns of air can be used to gain altitude without using the motor and propeller in the nose. Using received telemetry data, the RC controller is used to produce a vario sound in real-time. The barometer onboard the flight controller sends this verticle speed data via telemetry to the radio which enables me to track thermals, reporting if the plane is rising or falling.
I have been able to enjoy several flights of over an hour, using the motor in short bursts to gain altitude once eventually falling too near to the ground. Climbing to heights where the thermals are stronger, I can use them to stay aloft for long periods of time. I have been flying with either 2200, 2700 or 2900 mAh 3 cell LiPo batteries, putting the CofG ~10mm back from the marks on the underside of the wings.
This motor-glider uses a Matek-F765 flight controller running the latest ArduPlane firmware, providing flight assistance and return to home capabilities. Despite containing this very powerful F7 based flight controller, this flight was flown in manual mode and I used the on-screen display (provided by the Matek) for navigation purposes only. The return to home functionality provides a safety net, should I become distracted on the ground or lose radio or video link.
As enjoyable as it is seeing the plane fly itself, I have added the FC more for peace of mind, should a thermal take the glider beyond the range of the RC/video links. I find the real fun is in manually finding and tracking thermals!
Any questions? Please leave a comment!
Also a big thanks to my friend Josh, who 3D printed some parts for me :)
Specs:
Volantex 759-3 Phoenix 2400 EPO RC Glider Airplane
4023 1050KV Brushless Outrunner Motor
10x6 Folding Prop
40A Volantex ESC
3s 2200/2700/2900 mAh LiPo Battery
x6 Volantex 9g Mini Servo
FrSky 900 MHz R9mm Receiver and R9m Radio Module (with SmartPort Telemetry)
Taranis QX7 Radio, running OpenTX 2.2.4, using the Yaapu LUA telemetry script
Matek F765-WING FC (Arduplane firmware- version: Fri Jul 24 15:31:45 2020)
Beitian BN-880 GPS&Compass Unit
Holybro 433 MHz Telemetry Radios
Runcam Split Nano 3 FPV Camera
Aomway 3dBi Four Lobe RHCP antenna
Aomway 14dbi Rear Mount Patch antenna
Eachine TX5258 72CH 5.8 GHz Video Transmitter
Eachine LCD5802D Ground station monitor
Skyzone SKY03c FPV Goggles
*all flights took place over unpopulated fields and flight paths were carefully planned to ensure minimal risk to human life and 3rd party property. The landowner has permitted model flying from this specific field.