The use of flight check lists is highly recommended. Commercial operators will need to configure these to their particular requirements. Separate pre-flight check lists may be needed for DataPilot Missions and Manual Camera flights.
On the first flight of the day at any location: If the location is appreciably more East or West of where the last Compass Calibration took place, it may be necessary to re-calibrate it. After the craft is turned on, allow extra time for GPS acquisition. Subsequent flights during the day will go quicker. Also bear in mind that a good GPS fix here is important for the craft to know exactly its "Return to Home" point.
Before any flight: Never take off until after the craft icon (the plane) turns green unless you intend to fly in Manual Mode (no GPS). Tap the craft icon to see info on GPS Satellites, HDOP, and VDOP. A green line filling from left to right also indicates craft initialization. Tap the controller icon to view ST16s status. Because the 520 craft uses its GPS take-off point to key on for Return Home, the ST16s GPS basically is used only to measure horizontal distance to the craft. Ten or more GPS Satellites on the ST16s is needed for this distance to be accurate.
If the camera view is blank or goes blank and the message "Waiting for Video" appears for longer than a minute, turn the craft off, then turn off the ST16s. Wait 15 seconds, then restart the sequence, ST16s first. Allow the ST16s to boot to the craft acquisition screen before turning on the craft. Camera view usually appears in seconds after craft initialization, although EU systems may take a minute or so. See E90 info here: Known-E90-Bugs
Try to keep the ST16s battery above 50% if feasible, unless you have spare charged batteries. The reason for this is that a depleted ST16s battery, at 25% or 30% for instance, takes considerably longer than a flight battery to recharge.