Accident Details
On 20 November 2003, a Grumman G-164A (registration ZS-JEZ) was involved in an accident while conducting agricultural spraying operations near Hoopstad, South Africa. The pilot, who held a commercial license with 2,155.6 total flying hours (615.3 on type), was the sole occupant and was uninjured. The operator held a valid Aircraft Operating Certificate (Part 135) number G743D, issued on 30 June 2003 with an expiry date of 17 April 2004. The aircraft's last maintenance inspection (MPI) was certified on 14 November 2003 at 7,044.0 flying hours, with an additional 10.6 hours accumulated since.
Sequence of Events
The pilot had commenced spray runs earlier that morning but stopped due to strong winds. At approximately 1700Z, he resumed spraying and completed one load before returning for a second. During the second load, halfway through the field, he detected a smell resembling an electrical short circuit. As he approached the end of the field, the engine began to surge. He applied full power and fine pitch, then climbed gently, intending to land on a nearby road. However, the engine failed at an altitude of about 50 feet above ground level. The pilot leveled the aircraft and attempted to land on the same field, but trees obstructed the path. He stalled the aircraft over the trees and landed behind them. Upon touchdown, the main landing gear sank into soft soil, causing the aircraft to overturn and come to rest inverted.
Damage
No injuries were reported. The aircraft sustained extensive damage.
Probable Cause
The probable cause of the accident was failure of the brass bearing of the impeller of the supercharger, which caused impeller blades to break, resulting in a loss of engine power and a subsequent forced landing.