It appears to be the pilot of a cropduster aircraft that has been killed. Westside Aerial Services are the primary operator in that region.
Westside lost a pilot of an Air Tractor 502 (VH-ODP) when he hit a tree whilst cropdusting just over 4 yrs ago, about 140 kms WSW of this current crash site.
Plane crashes in Hyden - The West Australian
http://www.atsb.gov.au/media/3147585/ao2009060.pdf