Accident Overview
On July 2, 2022, at about 0944 eastern daylight time, a Grumman G-164A agricultural aircraft, registration N8923H, sustained substantial damage during an accident in Hopewell Township, New Jersey. The pilot, who was seriously injured, was conducting an aerial application flight under Title 14 Code of Federal Regulations Part 137.
Flight Sequence
The pilot was performing an aerial application over a nursery. As he pulled up at the end of a pass and crossed over an area of trees, he heard a "loud bang." Subsequently, he attempted to maneuver the airplane to land in an open field, but the airplane "ran out of altitude and airspeed" and impacted the ground.
Aircraft Damage
Examination of the airplane revealed that during the impact sequence, the engine and upper wing separated from their respective mounting locations.
Engine Examination
A postaccident examination of the engine was conducted. When rotating the propeller, the drivetrain rotated freely without binding. All engine cylinders were intact. The supercharger impeller was intact, but further examination revealed that it did not rotate when the propeller was moved by hand. The rear accessory/diffuser housing was removed to expose the supercharger impeller; no damage was noted on the external impeller blades. However, the rear splined impeller shaft ball bearing spacer (part number 13814) and supercharger impeller (part number 12788) splines were found to have sheared, allowing the impeller to freewheel.
Maintenance History
A review of the airplane's maintenance logs indicated that the engine had accumulated 7,598 total hours of operation and 1,031 hours since its most recent overhaul.