P.A. Amirault
Forest Protection Limited

SERG Project #2003/06
Year of Project: 2003
Report Received: 2007

A series of runs using the AgDRIFT (Version 2.03) model were done to simulate deposit from aerial applications to a small block. Results from a rotary wing aircraft (Bell 206) were compared to results from two fixed wing aircraft (Cessna 188 and Air Tractor 802). Each aircraft was subjected to conditions designed to approximate early morning (low wind speed, low temperature), later morning (higher wind speed and temperature), and a repeat of the early morning condition with a reduced application height.

The Air Tractor 802 produced the highest deposit in two out of three cases, but also produced large variations in deposit across the block. In the early morning scenario the Bell 206 produced the most uniform deposit across the block and the least drift. In the later morning deposit from the Bell 206 continued to be the most uniform and the peak of C-188 deposit occurred downwind of the block boundary. The reduced application height scenario produced the highest on block deposits and lowest drift for all aircraft types.

Results were not subjected to statistical analysis. They indicated the influences of aircraft height and wind speed were more important than differences in aircraft type. Advances in application technology were said to be crucial to properly locate and target small blocks.