What happened
On the day of the accident, a Cessna 150, registration N66234, and a de Havilland DHC-2 Beaver, registration N741DL, were involved in an in-flight collision while preparing to enter the downwind leg of the airport traffic pattern for runway 33. The incident took place about one and one-half miles northeast of the airport.
At the time, both aircraft were under the supervision of a developmental air traffic controller being monitored by a certified controller. The pilot of the Cessna 150 contacted the tower and was instructed to enter a right downwind via the forty-five. The controller warned of traffic ahead and to the right, but the pilot did not respond. Shortly after, the pilot of another de Havilland DHC and DHC-2 Beaver, registration N715JR, contacted the tower and was told the Cessna was passing behind him and was not a factor.
When the pilot of the accident N741DL made initial contact, the controller advised of a Cessna at 1,300 feet southbound. After several exchanges regarding traffic visibility and landing intentions—including the pilot's intent to land on the water—the pilot reported having an aircraft in sight ahead on the downwind leg.
As the sequence progressed, the controller instructed the Cessna 150 to proceed direct to the downwind and warned of traffic off the right wing. The Cessna pilot confirmed the traffic was in sight. During the maneuvers, the right wing of the Cessna 150 struck the left front float bow bumper of the N741DL. This was followed by the Beaver's propeller penetrating the upper outboard section of the Cessna's right wing. A final impact with the Cessna's empennage caused the aircraft to become uncontrollable, leading to a steep descent and impact with a vacant school building. The pilot of the N741DL reported the collision and landed the aircraft, which sustained substantial damage.
Findings
The collision resulted in no fatalities for the crew of the Beaver, though the Cessna 150 was destroyed upon impact with a building. The physical sequence of events involved the wing of the Cessna striking the float of the Beaver, followed by propeller strikes and structural damage to the Cessna's tail section.