N6781KGrumman Acft Eng Cor-Schweizer G-164B

On July 2, 2016, at 1030 eastern daylight time, a Grumman G-164B, N6781K, was substantially damaged when it nosed over following a forced landing to a farm field in Laurel, Delaware. The commercial pilot was not injured. The airplane was registered to the pilot and operated by Air Enterprises LLC under the provisions of 14 Code of Federal Regulations Part 137 as an aerial application flight. Day, visual meteorological conditions prevailed at the time, and no flight plan was filed for the local flight that originated from Johnsons Airport, Magnolia, Delaware (DE09), about 1000.

The pilot reported that he was making the last application pass about 20 to 60 feet above the ground when he heard a "loud bang" followed by a loss of engine power. He turned about 40 to 60 degrees to the left, into the wind, and set up for a forced landing in a corn field. The airplane landed on the corn and soft soil and nosed over.

The pilot held a commercial pilot certificate with ratings for airplane multiengine land, airplane single-engine land, and instrument airplane. He also held a flight instructor certificate with ratings for airplane single-engine land and instrument airplane. The pilot held a first class medical certificate and reported 6,700 total hours of flying experience, including 5,000 hours in the accident airplane's make and model.

An inspector with the Federal Aviation Administration responded to the accident site and examined the wreckage. Structural damage to the upper wing and vertical stabilizer and rudder was confirmed. Further examination revealed that the spray pump fan assembly was shattered, and pieces of the wooden fan blades penetrated the lower engine cowling. Bird feathers were also found inside the engine compartment, adjacent to the fan blade pieces. There was impact damage to the engine throttle linkage, which resulted in it bending and rotating to the idle/cutoff position.

On August 11, 2010, about 0715 Pacific daylight time, a Grumman Aircraft Engineering Corporation Schweizer G-164B, N6781K, experienced a loss of engine power while maneuvering to spray a field near Tracy, California. Trinkle AG Flying Inc., operated the airplane under the provisions of 14 Code of Federal Regulations Part 137 as an agricultural crop dusting flight. The commercial pilot/owner was not injured; the airplane sustained substantial damage to the wings, fuselage, and tail section. Visual meteorological conditions prevailed for the local area flight and no flight plan had been filed.

The National Transportation Safety Board (NTSB) investigator-in-charge (IIC) interviewed the pilot. According to the pilot, he had started flying about 0630 the morning of the accident. The accident flight was the second flight of the day. He reported that the airplane was loaded with 240 gallons of pesticide and about 35 gallons of fuel. While spraying a cornfield, he heard a loud bang, followed by a loss of engine power. The pilot also reported that the engine began shaking. He was able to land the airplane in an alfalfa field, but the field was slick and as he activated the left brake to intentionally ground loop the airplane, it did not respond. The airplane continued its forward movement until it struck a fence at the end of the field. The airplane came to rest inverted in a nearby ditch adjacent to the alfalfa field.

The engine was examined under the supervision of a Federal Aviation Administration inspector. During the examination, it was discovered that the head to the number five cylinder was cracked. In addition, the connecting links for all but the number 7 cylinder were broken and the master rod had sheared. They were unable to determine if the master rod or the connecting link failed first. No other anomalies were noted with the airframe or the power plant.