Accident Overview
A banner towing aircraft was conducting a checkout flight for a new pilot in banner towing operations. The first flight had been completed and the banner dropped. The aircraft then engaged the second banner. Witnesses saw the aircraft make the steep climb after pickup that is normally associated with banner towing. The aircraft was seen to slow, wobble, and fall off to the right in a spin from about 300 feet. One witness stated that the spin was stopped just prior to impact.
Witness Observations
Multiple witnesses observed the sequence of events. After the steep climb typical of banner towing, the aircraft's speed decreased. It began to wobble and then fell off to the right, entering a spin. The spin continued until just before the aircraft struck the ground, at which point the spin was reportedly stopped.
Post-Accident Examination
An examination of the aircraft and engine revealed no evidence of any pre-impact malfunction or failure. A loose 1-gallon thermos-type container was found on the floor of the rear cockpit. It was not positively determined whether or not the container had any bearing on the accident, creating an interference or distraction.