Last week, 140 km of power lines in the northern Stockholm archipelago got inspected in just three days. “It is fantastic to see the latest version of our software, Airpelago Power, perform this well”, says Airpelago CTO Tobias Fridén. With automated flights, the efficiency, as well as image quality increases, but it also makes the days in-field relaxed and joyful for the drone pilots. "I am extra pleased with how well it all works in the archipelago", Tobias continues.

It is 7:00 AM this April morning when two of our pilots cast off from a small dock north of Stockholm. Despite the early hour, the sun is already high in the sky this calm morning. Sparrows and blackbirds sing loudly and drown out the noise of the outboard engine as the boat leaves the harbor channel and sets course for the outer archipelago.

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Today’s mission is to inspect power lines on islands not accessible by car. After a 30 minute cruise, we reach the first island. The water is completely calm and the surface is flat as a mirror. The only ripple is caused by our boat slowly entering the shallow bay.

We unbox the drone from its hard-case and start to go through the day-of-operation- and pre-flight checklists. After its completion, the drone takes off quietly and is airborne a few minutes after we arrived at the bay. The drones automatically raises straight up to 35 meters and then sets course towards the power line. The first part of the flight, from the take-off to the first part of the power line is usually referred to as a "ferry flight".

As the drone flies toward the power line we lose sight of it less than 30 seconds after take-off as it disappears behind the first treetops. We continue to monitor the drone via the remote controller through which we retain a live video feed and telemetry data throughout the flight.

The flight is estimated to take about 4 minutes in total, and in this time the drone inspects just a little more than a kilometer of the power line. The flight goes well and after about three minutes into the operation, the drone returns to its take-off position and becomes visible to us again.

All safety settings are set by the Airpelago Power app, and if the connection to the drone would be lost, the drone automatically initiates a return-to-home procedure, which starts with the drone rising a few meters in altitude, most often resulting in the connection being restored within a few seconds. If the connection isn't restored, the drone will safely return to its start position.

As soon as the drone is safely back on the ground, we put the battery on charge and prepare for relocating to the next optimal take-off position. This procedure is repeated several times throughout the day until we have covered the whole mission of the day.

We cruise for a few minutes to the next place and have the drone airborne again. A sea breeze of about 2-4 m/s has now kicked in as the sun warms the land. We don't worry about the flights as the drone platform we deploy today, the Mavic 2 Pro, has a wind resistance of up to 10,5 m/s. 

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As we got up early this morning we decide to pause and have a cup of coffee and a sandwich before relocating to the next take-off site. Cheers!

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The procedures are repeated throughout the day; we are off to the next jetty, next flight, and next power line to be automatically inspected by our drone.

It became a long day and in total, we sailed 87 nm (161 km) before we finally docked the boat at around 7 PM.

Back at the hotel, and before safely uploading the images to the client's service, we have a  delicious dinner. We feel grateful for a fantastic day at sea!