The work cycle consists of the following elements: operations at the working airstrip – refuelling with fuel and chemicals, taxiing and take-off to transit altitude, transit to the work zone, working flight over the crop repeated until the chemical tank is emptied or the field is completed. Successive flights are offset by the working width; turns after each working pass are made at an altitude of 50 m.
Their duration is approximately 1 minute, followed by a return to the working airstrip or transit to the next field. The working flight pattern is analogous for fertilising and spraying, differing only in flight altitude. Guidance onto the next working run was until recently accomplished with the help of so-called flagmen, who held a board on the flight line and moved it by the working width for each successive pass.
Nowadays guidance is carried out using GPS. The pilot enters field data, the location of terrain obstacles, wind strength and direction into the onboard computer and flies while observing the recommendations on the indicator screen. From GPS memory, the entire work cycle can be replayed after the flight.
The cycle of each agrotechnical flight is the time counted from the moment of the initial movement of the aircraft (at the point of loading it with chemicals or mineral fertilisers) to the moment of stopping at the same loading point after returning from the working flight. — J. Krężałek*
