It happened around 4:15 p.m. Thursday just west of the Cross Keys Airport in Williamstown.
Police said the single-engine Cessna 150G plane went down while the 62-year-old male pilot was attempting to lift the banner.
Chopper 6 was overhead as the victim was brought out from the woods, put on a stretcher and taken to a hospital.
There was no immediate word on his condition.
The FAA is assisting with the investigation.