Field testing of recoverable sounding systems in South Africa.

01. The shelter at the flying field where the powersonde tests were performed.

02. Filling the powersonde with fuel…unleaded gasoline with 2% oil.

03. Recycling is always a possibility. What goes up must come down, the only uncertainty is how it comes down. Flying fields always have recycle bins…

04. On-off power switches are located along the side of the powersonde…

05. Note the balsa pods for housing the RS-80 radiosonde (left side of photo) and the corresponding counter-pod on the other wing.

06. closer view of the sensors sticking out from the pod on the port wing.

07. getting ready to test start the engine. The engine was new, and performance improved with use.

08. takeoff into the wind… not necessarily along the runway!

09. although the powersonde was flying autonomously at this time (the radio controller that Davis Egle has in his hand is not operating), it was always followed visually (as much as possible) in case a problem developed. Here the powersonde is flying in front of the sun…

10. Telemetry data being displayed on the laptop in the back of the trailer…

11. Close-up of the screen display during one flight. Note that the jumps in the height versus time display in the lower left corner of the screen are due to the change between pressure altitude above ground level and GPS-determined altitude above sea level that occurred at 3000 ft AGL (problem since corrected).

12. Access to various components of the powersonde was through a belly hatch.

13. Closer view of photo 12.

14. Note wing tip pods for the radiosonde (left side) and ballast pod on the right side.

15. Notice how a hard landing makes for easy packing! Actually, on the last flight the powersonde ran out of fuel and made a somewhat hard landing at the edge of the flying field. The landing gear got caught in high grass/animal burrows and flipped over. Despite the neat separation of the fuselage, no essential components were damaged (the wings separate for transportation normally) and this powersonde flew only a few days later! All surfaces have a fiberglass cloth coating and are quite durable.