Incident Overview
Two Stearman aircraft were assigned to pick up banners laid out on the ground. An extra banner was present among the designated pickup banners. The two aircraft approached the pickup point as a flight of two.
Sequence of Events
As the first aircraft lifted its banner, the extra banner became entangled with the intended banner, resulting in both banners being carried into the air. When the second aircraft approached the pickup point, the extra banner separated and began falling. The pilot of the second aircraft did not see the free-falling banner because forward visibility was reduced by the upper wing.
While the second aircraft was making its own banner pickup and beginning its initial climb, the descending banner made contact with both the upper and lower left wings. According to the pilot, the left wing then stalled, causing the entire aircraft to stall onto the runway.
Damage and Injuries
The aircraft sustained substantial damage. The upper wing fuel tank ruptured and was leaking fuel, but there was no fire. The pilot received serious injuries.
Conclusion
No official probable cause has been stated in the source material.