What happened
On August 9, 2015, an Aviat Husky A-1, registration N6090U, crashed at Compton/Woodley Airport in Compton, California, during a local banner tow flight. The flight was being conducted under visual meteorological conditions with 10 miles of visibility and light winds.
Ground personnel observed the pilot attempt to pick up a tow banner five times without success. On the sixth attempt, the pilot successfully attached the banner, and the engine appeared to be operating normally. However, the pilot subsequently radioed ground staff to report that the aircraft was unable to climb. Witnesses then saw the banner detach from the tail hook and fall to the ground. The aircraft began wallowing side to side before entering a left-hand spin. The airplane impacted the ground south of runway 25L and was destroyed by the impact and a post-crash fire. The pilot sustained 1 fatal injury.
The investigation
Investigators examined the wreckage in Phoenix, Arizona. The engine, a Lycoming O-360-A1P, was found to be intact with no mechanical anomalies that would have prevented normal operation. Cylinder compression was established, and the oil screen was clear of metallic debris. The flight controls were found to be continuous and all surfaces were properly attached. The tow hook was found in the released position and showed no abnormalities. The banner and tow rope showed no damage.
Training records indicated that while the pilot had completed banner tow training in 2013, his instructor had previously noted several safety issues during 2014, including low approaches, nonstandard patterns, and improper power application. Toxicological testing performed on the pilot was negative for drugs and carbon monoxide.