CEN20LA364

Shortly after takeoff, the pilot of an agricultural airplane experienced a total loss of engine power. Unable to restore engine power, the pilot made an emergency landing in a cornfield, which resulted in substantial damage to the airplane. The engine was removed from the airframe and an engine examination revealed small bits of metal in the oil filter element and that the engine was seized. The top cylinder was removed, the cylinder’s connecting rod was broken, and metal fragments were noted inside the engine. A bottom cylinder was then removed, and a broken section of the master connecting rod was retrieved. Metallurgical examination determined that the connecting rod separated due to overstress fracture, with no indication of pre-existing cracking.

On August 24, 2020, about 1550 mountain daylight time, a Grumman G164B airplane, N2437D, sustained substantial damage when it was involved in an accident near Ogallala, Nebraska. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 137 agricultural flight. According to the pilot, the airplane had flown earlier in the day, and he departed for another agricultural flight. The pilot stated the engine lost power during the climb shortly after takeoff. He dumped the load, checked the magnetos, and made sure the fuel was on. The pilot then made an emergency landing in a cornfield about 1.85 miles from the airport. Upon landing, the bottom wing impacted corn, which caused the airplane to nose over. The airplane sustained substantial damage to the wings and empennage during the forced landing. A postaccident engine examination revealed small metallic pieces in the oil filter element. The engine could not be rotated by hand. The top cylinder was removed; the cylinder’s connecting rod was broken, and metal fragments were noted inside the engine (see figure). Figure: Top cylinder with broken connecting rod. A bottom cylinder was then removed, and a broken section of the master connecting rod was retrieved and sent to the National Transportation Safety Board (NTSB) Materials Laboratory for a detailed examination. The NTSB lab noted that different areas of the connecting rod fracture surface were consistent with overstress fracture. There were no indications of pre-existing cracking features.