The afternoon before our first flight, I requested a NOTAM via Mac Centre. Our intended flight was within a 3nm radius of Spaulding Pond and would be conducted below 400' AGL. Fox Field is about 870 AMSL. The objective of the flight was primarily to discover any unforeseen difficulties in operating the Fox in the Antarctic conditions, but taking advantage of being in the air, we would carry two Sony NEX5-N cameras and map the Spaulding Pond.
The following day, the first major task was to find "pack mules" to help me carry the UAV and GCS cases to Fox Field. This is only about 500m from K020 Base Camp, but the Pelican case holding the UAV is a bit ungainly for one person to carry, and the built-in wheels were no use on the rocky valley floor.
After we reached the site, I set up the GCS and assembled the Fox - two fresh batteries were installed and the cameras had clean 32GB cards fitted. As I was the only trained UAV pilot in the Valley, I began by instructing my colleague, Scotty, on what would be required of my "wingman". At this early stage, he would be holding things, hooking on the catapult and acting as observer.
Our first difficulty became apparent almost immediately: the fixed end of the catapult is attached to a spike driven into the ground. The very loose nature of the valley floor allowed the spike to pull free as soon as any load was put on the bungee. Fortunately, there was a simple solution: drive a long tent peg into the ground on the far side of a large rock and place another rock on top of the peg. We used this arrangement for all future flights with no problem.
Scotty and I went through the pre-takeoff checklist, a printed document, and determined the the aircraft was ready to fly - all control surfaces were moving as expected, the autopilot was making corrections for pitch, bank and yaw, the pitot tube was clear and correct telemetry was being received by the GCS. The final check was to set the emergency landing point, on this occasion approximately 30m from the GCS. If the link with the GCS is permanently lost, the aircraft will attempt to return to this point and land.
The second problem to arise was the result of the extreme interest shown by the remaining team members in the UAV. They had seen me preparing the aircraft back at Scott Base and checking it at K020 Base Camp, so when the time finally came for the first flight, there was quite an audience, requiring a measure of crowd control. This is always an issue for UAV operators, but fortunately, a simple request for them to stay behind the aircraft was heeded by everyone. The last thing the handler wants is for a spar to break on takeoff, with the aircraft diving at full power into the onlookers.
Scotty hooked on the catapult and went back to the GCS computer. I got on the radio on the helicopter frequency. "Taylor Valley Traffic, Fox UAV is about to take off, 3nm radius, Spaulding pond". I took 20 paces backwards to tension the bungee and called for Takeoff Mode. Scotty entered this into the computer and called confirmation that the computer warned that the aircraft would take off and engine start. I saw the elevons rise, which told me the Fox was ready to go. I gently bounced the aircraft against the pull of the catapult and released it in a 15 degree nose-high attitude. To my great relief, the Fox shot out of my hands, the motor started in response to the acceleration, and the aircraft climbed at full power. A few moments later, the motor cut to a lower power setting and the Fox began to circle the launch point while it climbed to its set altitude of 1270ft AMSL.
For the first flight, I had decided to enter waypoints into the GCS manually during the course of the flight, so when the Fox reached operational altitude, I entered the first waypoint as the Eastern end of Spaulding Pond and turned on the cameras. The Fox immediately set off on track and soon reported "On approach" approximately 1000m from the launch point. I turned the cameras off and programmed a left turn and then another transect of the pond, attempting to get a camera footprint overlap with the first transect, so that the images could later be stitched into an orthomosaic. Cameras back on for the transect and off before the next turn. This process continued, back and forth, until we had covered the whole of the lake. Craig, the expedition leader, described this as the "lawnmower pattern".
I recalled the Fox and commanded an automatic landing. The aircraft reduced altitude to about 150' AGL and released the parachute. When the chute inflates, the aircraft bunts inverted, so that the sensor window and cameras are protected from the impact. In this case, I use the word "impact" advisedly, as the valley floor is strewn with rocks of all sizes, even at Fox Field. However, the landing was uneventful, if a little firm, and we recovered the aircraft to the applause of the onlookers. During the short flight, we collected approximately 500 images.
Odd Spot: There were many cameras operating for the first launch, and one video captured the remarks of a bystander as the Fox leapt into the air. The gist of what he said was "Gosh, that was amazing". I wonder if his Mum taught him to speak like that?
The following day, the first major task was to find "pack mules" to help me carry the UAV and GCS cases to Fox Field. This is only about 500m from K020 Base Camp, but the Pelican case holding the UAV is a bit ungainly for one person to carry, and the built-in wheels were no use on the rocky valley floor.
After we reached the site, I set up the GCS and assembled the Fox - two fresh batteries were installed and the cameras had clean 32GB cards fitted. As I was the only trained UAV pilot in the Valley, I began by instructing my colleague, Scotty, on what would be required of my "wingman". At this early stage, he would be holding things, hooking on the catapult and acting as observer.
Our first difficulty became apparent almost immediately: the fixed end of the catapult is attached to a spike driven into the ground. The very loose nature of the valley floor allowed the spike to pull free as soon as any load was put on the bungee. Fortunately, there was a simple solution: drive a long tent peg into the ground on the far side of a large rock and place another rock on top of the peg. We used this arrangement for all future flights with no problem.
Scotty and I went through the pre-takeoff checklist, a printed document, and determined the the aircraft was ready to fly - all control surfaces were moving as expected, the autopilot was making corrections for pitch, bank and yaw, the pitot tube was clear and correct telemetry was being received by the GCS. The final check was to set the emergency landing point, on this occasion approximately 30m from the GCS. If the link with the GCS is permanently lost, the aircraft will attempt to return to this point and land.
The second problem to arise was the result of the extreme interest shown by the remaining team members in the UAV. They had seen me preparing the aircraft back at Scott Base and checking it at K020 Base Camp, so when the time finally came for the first flight, there was quite an audience, requiring a measure of crowd control. This is always an issue for UAV operators, but fortunately, a simple request for them to stay behind the aircraft was heeded by everyone. The last thing the handler wants is for a spar to break on takeoff, with the aircraft diving at full power into the onlookers.
Scotty hooked on the catapult and went back to the GCS computer. I got on the radio on the helicopter frequency. "Taylor Valley Traffic, Fox UAV is about to take off, 3nm radius, Spaulding pond". I took 20 paces backwards to tension the bungee and called for Takeoff Mode. Scotty entered this into the computer and called confirmation that the computer warned that the aircraft would take off and engine start. I saw the elevons rise, which told me the Fox was ready to go. I gently bounced the aircraft against the pull of the catapult and released it in a 15 degree nose-high attitude. To my great relief, the Fox shot out of my hands, the motor started in response to the acceleration, and the aircraft climbed at full power. A few moments later, the motor cut to a lower power setting and the Fox began to circle the launch point while it climbed to its set altitude of 1270ft AMSL.
For the first flight, I had decided to enter waypoints into the GCS manually during the course of the flight, so when the Fox reached operational altitude, I entered the first waypoint as the Eastern end of Spaulding Pond and turned on the cameras. The Fox immediately set off on track and soon reported "On approach" approximately 1000m from the launch point. I turned the cameras off and programmed a left turn and then another transect of the pond, attempting to get a camera footprint overlap with the first transect, so that the images could later be stitched into an orthomosaic. Cameras back on for the transect and off before the next turn. This process continued, back and forth, until we had covered the whole of the lake. Craig, the expedition leader, described this as the "lawnmower pattern".
I recalled the Fox and commanded an automatic landing. The aircraft reduced altitude to about 150' AGL and released the parachute. When the chute inflates, the aircraft bunts inverted, so that the sensor window and cameras are protected from the impact. In this case, I use the word "impact" advisedly, as the valley floor is strewn with rocks of all sizes, even at Fox Field. However, the landing was uneventful, if a little firm, and we recovered the aircraft to the applause of the onlookers. During the short flight, we collected approximately 500 images.
Odd Spot: There were many cameras operating for the first launch, and one video captured the remarks of a bystander as the Fox leapt into the air. The gist of what he said was "Gosh, that was amazing". I wonder if his Mum taught him to speak like that?
Labels: Antarctica, AUT Fox, check list, Fox Field, NOTAM, UAV
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