An aircraft separation incident between an unmanned aerial vehicle and crop duster highlights the challenges with having a diverse mix of aircraft operating in the same airspace.
On 12 September 2013 the pilot of an Ayres S2R commenced aerial agricultural spraying operations on a property near Horsham, Victoria. At about the same time, the operator of a UAV, Sensefly eBee 178, arrived at ‘Iluka Echo’ (Echo) mine site to conduct an aerial photography survey of the site. After completing his pre-flight preparation and risk assessment of the operation, the operator heard an aircraft operating about 1 – 1.5 km away on a neighbouring property.
Pilots of UAVs are required to operate at or below 400 ft but approval can be granted to operate higher...
The UAV operator broadcast on the area frequency advising his intention to conduct unmanned aerial photography operations over the Echo mine site but did not receive a response. He then asked the mine manager to contact the farmer, who was loading fertiliser into the hopper of the Ayres aircraft to advise him of the UAV operating in the area and advise the pilot.
The UAV then commenced operations. After completing the first load of fertiliser the pilot of the Ayres aircraft reported that the farmer informed him that there would be an ‘aircraft’ conducting aerial photography over the mine site, near one of the areas he would be operating on. The pilot assumed that this would be a fixed-wing aircraft operating at or above 500 ft AGL. Accordingly, he intended to remain at or below 350 ft to ensure separation.
During their operations the two aircraft came within 100 m of each other. The pilot of the Ayres reported that he did not see the UAV at any time, although he was aware of a white vehicle parked on the road. He was not aware of the procedures for UAV operations. The UAV operator advised that in future, even if unable to contact the pilot via radio, he would ensure he spoke directly to the pilot of any aircraft operating in the same area as the UAV. This would assist in increasing awareness and understanding of UAV operations.
Pilots of UAVs are required to operate at or below 400 ft but approval can be granted to operate higher—in this case a NOTAM would be issued (A NOTAM is a notice filed with Airservices to alert other pilots of potential hazards.) All UAV operators are also required to broadcast on the appropriate frequency. Pilots and operators need to remain vigilant and employ ‘see and avoid’ principles and they need to recognise that small UAVs may be difficult to see.