http://www.wingsmagazine.com/content/view/490/38/
The term “bird-dog” originated with the US Army. In the late 1940s, it started using the single-engine Cessna 305 for liaison duties, and created the name “bird-dog” for the rugged, little airplane. The C305 was also used by the US Forest Service for wild land fire patrols and other operations. “Bird-dog” has been applied to fixed-wing aircraft involved in the coordination of aerial firefighting ever since.
The initial attack on a forest fire begins with the forest service coordination centre notifying a tanker group to launch. The first aircraft from the group to take off is the bird-dog; onboard is the pilot and a forest service Air Attack Officer (AAO). As the birddog approaches the fire, the AAO conducts an initial assessment. The pilot then flies orbits at 1,500 to 2,000 feet AGL, allowing the AAO to better assess the fire, develop an attack strategy, look for structures and hazards and select the first target and bombing run direction. The bird-dog then descends to about 150 feet above the trees to conduct an inspection of the tankers run. The bird-dog team checks for hydro lines, rises in terrain,d. and other hazards, and notes the turbulence and visibility on the approach to the fire and over it. This information is then communicated to the tanker pilots.
http://randomramblingsfromnj.blogspot.com/search/label/"bird dog" planes
I wrote the other day about Conair (from Canada) leasing five tankers and a "bird dog" plane, a 690 Turbo Air Commander to Victoria, Australia for their summer season. What is a bird dog plane? A bird dog plane in Canada is similar to a lead plane in the U.S. One of the functions of a bird dog or lead plane is to sniff out the route that the tankers will take to drop retardant on a fire. Simply, the lead or bird dog plane leads the tanker to the site of the retardant drop.