<p>An aerial saw (10) suspended from a helicopter (100) comprising: (a) saw blades (30) offset and overlapped with a small running clearance (b) power source (50), a pump (90) and tank (91) provided in a housing (40) at the lower end of the main beam (40) (c) spray nozzles for spraying tree-treating chemicals onto the blade teeth the aerial saw (10) being suspended from the helicopter (100) by a steerable boom (120) to compensate for yaw and drift of the helicopter (100) in windy operating conditions.</p>
