On March 12, 1994, an American Champion (acac) 8KCAB (registration N189AC) operated by Michael P. Ilyin was involved in an aviation accident near Marana, AZ. Investigators recorded the probable cause as: The pilot's delayed pullout from a vertical aerobatic maneuver for undetermined reasons. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
Aircraft registered N189AC. Photo: Adam Dubrowa / Public domain, via Wikimedia Commons
Witnessed by aerobatic judges, an aircraft performing a hammerhead turn descended vertically before a late pullout near the ground. The engine remained at near full power throughout. No flight control discrepancies were found.
Accident Overview
Judges from the International Aerobatic Club witnessed the accident while grading the pilot's aerobatic performance. The pilot was executing the 1994 Intermediate Known Sequence, which included a hammerhead turn course reversal. The maneuver called for a 1/4 roll on the up line and a 1/4 roll on the down line.
Sequence of Events
Following the hammerhead turn, the aircraft descended vertically. Witnesses reported that they did not observe any attempt to initiate a pullout until the aircraft was very near the ground, at which point a change in attitude of 10 to 15 degrees was noted. The engine continued to operate at near full power throughout the maneuver until ground impact.
Wreckage and Flight Controls
All components of the aircraft were accounted for along the wreckage path. An examination of the entire flight control system documented no discrepancies. No further details regarding the aircraft type, registration, or operator were provided in the investigation source.
