Pre & Post Flight Procedures
A methodical set of procedures will help ensure that no disasters occur due to a silly oversight.
Before each flight you should check the following:
- i) Flight battery condition – use a cell-checker (or built-in indicators)
- ii) Props on tight, the right way up, on the correct motors.
iii) Failsafe armed. Are you certain that on this equipment the failsafe has been set up and the RTH function is available to you?
- iv) Security. Here you are checking that nothing is loose. Vibration is always present at some level on quads, and this can result in nuts and setscrews shaking loose over time. Also batteries are removed for charging, so you need to check that they have been securely reattached. Finally, if you are carrying a camera or any other type of load, make sure that it is still firmly attached.
- v) Transmitter.
(1) No battery warning showing
(2) All switches up
(3) Antenna correctly positioned
(4) Throttle at zero. (For DJI transmitter the throttle is sprung loaded at middle setting – but the Combined Stick Command (CSC) ensures that the motors are not live. With other transmitter or Flight Controller types you must ensure that the throttle is set to zero before powering up the quad as it could leap up straight at you.)
vi) Weather still suitable?
- i) Eventualities: Now is the time to think through your options if things do not go to plan.
(1) Let go. Almost certainly it is a command that you are giving erroneously that is causing the problem.
(2) Switch to GPS mode. The quad will hold position whilst you collect your wits. (Don’t cut the throttle just because you get a little confused – the quad will fall to the ground and sustain damage if you cut the throttle.)
(3) If definitely crashing, cut the throttle. This will save the props and motors – and save whatever you are crashing into from prop strike damage.
Turn on the transmitter first, then power up the aircraft. (Remember this as First On, Last Off (FOLO))
Allow the initialisation process to complete. If using a DJI quadcopter wait until a full satellite lock has been obtained and the burst of green lights has shown. Check that you have the expected light signals showing (flashing green in GPS mode, flashing amber in Atti mode).
Check that all switches are up then input the Combined Stick Command (CSC) and power up to launch.
In Flight Checks
During the flight you will need to stay alert to:
- i) Battery status: this might be a low battery warning lights on the quad, or through the use of a timer function on your transmitter or some other system.
- ii) Visual Line of Sight: you need to avoid flying the machine too far away from yourself.
iii) De-confliction / separation from manned aircraft.
- i) Post-flight actions. The first action should be to power-down or disconnect the flight battery, followed by the transmitter battery.
- ii) Post-flight maintenance. You should give the quad a once over, just like the pre-flight inspection, to see if there are any issues that will require attention before your next flying session.
iii) If the quad has been involved in a crash, you will almost certainly need to carry out an IMU recalibration. With the DJI equipment this involves using a computer and the Software Assistant – but is entirely straightforward.
It is a good idea to hand test for correct pitch, roll, yaw control functions and axis movements whenever any maintenance has been carried out – including changing propellers (as on most types it is easy to fit a clockwise prop onto an anti-clockwise motor). But you must have a really firm grip on the quad, with no loose clothing, and hold it in such a way that the spinning propellers are well clear of all parts of your anatomy. Having a suitably skilled helper operate the transmitter is a good idea.
See next section here: Drone Flight Exercises