Limitations

Flight Control

For all flight modes except Manual, at altitudes below 2 meters, tilt angle is reduced to 12 degrees and vertical speed is reduced to 0.7 m/s.
The purpose is to prevent tipovers on landing, but has the side effect of reducing speed if flying below the takeoff point (e.g. surveying from a high vantage point). We are working to correct this behavior.

Environment

Temperature

Astro can operate between -20 and 50 C. Position mode and survey flying are normal throughout the range. However, care is needed to operate at low and high temperatures.
Yellow region: Hovering and aggressive flights may give overtemp warnings. Follow the warning instructions.
Blue region: If batteries become too cold, state of charge will decline quickly and aircraft will enter Return or Land mode. Keep batteries warm, above 10 °C at takeoff, then self-heating will keep them warm.

Tips for operating in hot environments

At high temperatures, the limiting factors are motor and battery temperatures. AMC will display a warning if the motors or batteries become too hot. Heed the warnings! Astro operates normally in forward flight up to 15 m/s with full payload of 1500 grams.
Cooling air is your friend. The motors get much more cooling air in forward flight than at a hover. Overheat errors may occur when hovering because there is less airflow, or when flying aggressively because heating increases with current.
Batteries may require cooling before charging. Bring an extra set of batteries and chargers to enable continuous flying. If you connect batteries to the charger while cooling, they will automatically begin charging as soon as they have cooled sufficiently.
Keep equipment out of direct sun, Herelink especially. Herelink will shut down if it overheats, and it does not give a warning.

Tips for operating in cold environments

At low temperatures, battery cell temperature is the limiting factor. When the cells themselves are below 10 °C (ambient air can be down to -20 °C), the built-in battery management system's (BMS) state of charge (SoC) algorithm has reduced accuracy. The SoC may decrease to zero suddenly. If this happens, low battery failsafes (RTL and Land) will be triggered, causing the aircraft to climb or descend suddenly.
These failsafes can be over-ridden by selecting another flight mode (over-ride by moving the sticks is not available during failsafe). The battery will not cut off power output in the air, however low temperatures generally reduce capacity which will reduce flight time.
If the batteries are 10 °C or warmer at the start of a flight, heating from discharge will keep them warm enough to fly.
To keep batteries warm, charge them in a heated environment and store them in an insulated container (a cooler works well).

Wind

In high wind, Astro will give a warning.
Flying Astro is high wind is not advised. If the wind speed is a significant fraction of Astro's top speed, control authority will be diminished in all flight modes.
When Astro is not flying, fold the props and install proptectors. If the wind blows through open props, it can cause them to spin up dangerously.

Rain and Dust

Astro can operate in moderate rain (approximately 3 mm per hour). USGS has a guide (scroll to bottom) to help translate between forecasts like "shower" or "drizzle" to accumulation amount.
Battery connectors cannot be mated while wet or containing debris. We recommend compressed air to clean the connectors.

Tips for operating in Rainy and Dusty environments.

Rain in particular increases the risk of electrical malfunction because it can lead to short circuits
Dust carries a risk of mechanical malfunction because it can enter the motors and obstruct rotation.
Both of these conditions carry increased risk of malfunction and danger. It is difficult to judge the exact amount of precipitation, and the amount can vary without warning during the course of a flight. Therefore, we recommend avoiding situations that endanger people.

Radio Interference

Operating with a weak signal, whether due to interference or long range, can cause loss of link with the aircraft, which will engage failsafes. If you anticipate a weak signal situation, double check that failsafes are set appropriately.

Range

Range is approximately 2 km in ideal conditions, no interference and the Herelink patch antenna pointed toward Astro.
Range can be reduced by radio frequency interference from other Astros or sources like wifi networks. Obstacles like trees and buildings dramatically reduce range.

Multiple Aircraft

The Herelink controller as configured for Astro permits 4 aircraft to fly simultaneously in close proximity. If more aircraft are present, interference can cause loss of radio link and control.
Last modified 3mo ago