Sequence of Events
A banner towing aircraft, registration N7510H, contacted the tower southeast of the airport using the radio frequency designated for the north runway. The flight was cleared to descend through the traffic patterns for Runways 9R and 9L to 500 feet for a banner drop. Simultaneously, N48977, a Cessna, took off on Runway 9R for a touch-and-go landing and was using the radio frequency for the south runway.
Air Traffic Control
The controller provided N7510H with traffic information, noting Cessnas on the downwind leg for Runway 9R. Two other Cessnas were already on downwind; N48977 had not yet turned downwind. The pilot of N7510H acknowledged seeing the traffic. The controller then advised the Cessnas on downwind of banner towers inbound from the south.
The controller was managing a combined position covering two runways and two radio frequencies, with several aircraft in each pattern. She stated that due to workload, she did not have time to give specific traffic instructions to N7510H and N48977.
Witness Observations
The pilot of the Cessna ahead of N48977 reported that as he turned downwind for Runway 9R, sunglare reduced visibility. Shortly after N48977 turned downwind for Runway 9R, N7510H and N48977 collided at a 90-degree angle.