Officials are using the smaller craft more frequently and sooner to fill the gap.
Steve Fletcher, a pilot fighting what has been Arizona's largest blaze of the year so far - the Willow fire near Payson - said firefighters are becoming more aggressive in attacking fires while they are still small.
``They're not going to wait to get a big, huge (plume of) smoke on the horizon,'' Fletcher said. ``They're going to go after them when they're little.''
Fletcher's aircraft, which can haul up to 800 gallons, has been stationed at the Payson airport since mid-May.
As many as 16 similar aircraft also have been placed across the state to ensure they are readily available for initial attacks, when smoke is first spotted. Aircraft are used to drop water and retardant on and around wildfires to help firefighters on the ground.
Bob Simpson, the U.S. Forest Service's manager of single-engine air tankers, said the smaller aircraft are just as efficient in the initial stages of a fire.
``Once the fires get large, they may not be as effective,'' he said. ``If it gets real windy, it may not be enough.''
The aircraft that have fought the Willow fire have included two C-130 military cargo planes, which can carry about 3,000 gallons of retardant, two ``sky cranes,'' which carry up to 2,000 gallons, and Fletcher's single-engine air tanker.
When the 33 large air tankers were taken out of service in May, officials had warned that it would be devastating to firefighters.
Yet, those air tankers dropped only 20 percent of the retardant on wildfires over the past 10 years, said Danny Kellogg, the U.S. Forest Service's Southern Regional Aviation Operations specialist.
For now, the smaller planes appear to be filling the void, even though they can't fly as far or as fast as larger planes, and they carry lighter loads of retardant.
To their advantage, the smaller planes fly as low as 60 feet above the ground and can hit their targets more precisely.
``They can be more maneuverable in the rugged terrain and hit some hot spots directly that some of the larger aircraft can't get to,'' Simpson said.
Even when the largest aircraft were available, ``we had large fires burn out of control,'' he said.
``We'll probably have large fires whether we have large air tankers or not,'' Simpson said. ``To say missing large air tankers from our tool box will equate to more large fires, I don't think so.''