But the ASM can have a second function, that of air attack. As I understand it, the primary function (but not necessarily the only function), of air attack is to coordinate aircraft over the incident fire. This would include communications with the incident commander on the ground and communication with aircraft working the fire.
I'll let Larry explain the ASM function in a little more detail:
The ASM can function as an Air Attack if there is no other Air Attack available over the fire. When that's the case,the ASM will orbit the fire at 1000 ft or higher between tankers to allow the Air Attack to get a good view of the fire in order to plan and co-ordinate the attack on the fire by all resources. The Air Attack will normally be in radio contact with the Incident Commander (Fire Boss),with Dispatch and the air resources.
It's not unusual for the ASM to go to a fire as an initial attack resource and decide that tankers are not needed and then remain over the fire as Air Attack, even if there are no other air resources (helicopters,for instance) are assigned. In that case, the Air Attack will be talking to the firefighters on the ground and with dispatch.
When a tanker arrives,the ASM functions as a leadplane.It then reverts to Air Attack when the tanker leaves. If there is a full time Air Attack available over the fire, the ASM can still take over and act as Air Attack if the normal Air Attack needs to go in for fuel or relief.