The primary aircraft was somewhat imprecise in flight yesterday. We calibrate the gyro and acceleration sensors during the day. We could only do short (15 minutes) flights as the batteries were too cold. The pressure hoses enter the aircraft at the tip, just in front of the battery. We tight it with extra foam. The heat searation foam behind the autopilot is renewed. We isolate a plastic box with foam for battery storage and put heating pads between the lithium-polymer batteries.
We leave at seven. The two fragile sensors are screwed in at the airport and we head down to the campsite by the fjord. The trunk of a small van is our base. We test new batteries from HK. They cannot proved a high (but adequate) current, but 50% more capacity (at the same weight) than the current favorites from SLS . They seem to work fine even under this conditions. We achieve flight times of about 40 minutes and have a 10% spare. The planes work well and make their rounds over the sea and land reliably.
A lit up fishing trawler moves in the jord in front of us. There is a thin layer of fog above the water surface. The air temperature is -14°C, the ground is -20°C and the fjord is -3°C. This is not incredibly cold, but uncomfortable. Especially if you stand more or less motionless, looking at the sky and actually standing on that ground. It is really nasty when the wind is up. Thermos flasks do not only give you a warm but also non-frozen drink.