On July 23, 2006, at 0645 eastern daylight time, a Grumman G-164A, N6620Q, operated by Downstown Aero Crop Service Inc. was substantially damaged during a forced landing following a loss of engine power during the initial climb from Vineland-Downstown Airport (28N), Vineland, New Jersey. The certificated airline transport pilot received minor injuries. Visual meteorological conditions prevailed, and no flight plan was filed for the local aerial application flight, conducted under 14 CFR Part 137. According to the pilot, he had made approximately 400 flights in the accident airplane during the season with no indications of any malfunctions. The preflight inspection, which included "sumping" the fuel system, was routine, and no problems were discovered. At approximately 0630 he started the airplane's engine. The "warm-up run" was normal, and no anomalies were noted during the magneto and propeller checks. After loading the airplane with a 150-gallon spray load, he taxied from the "spray ramp" and departed. During a climbing right turn for noise abatement, at approximately100 feet above ground level, he heard a loud "bang," quickly followed by a total loss of engine power. The pilot jettisoned the 150-gallon spray load and landed straight ahead, touching down approximately 300 feet from the departure end of the runway in a plowed field. After touching down firmly, the airplane rolled out approximately 50 feet, and nosed over. The pilot was unable to exit the airplane as the doors were jammed closed in the soft earth of the plowed field, and had to be assisted in order to egress. According to Federal Aviation Administration (FAA) records, the pilot held an airline transport pilot certificate with multiple ratings including airplane single-engine-land, airplane multiengine-land, and instrument airplane. He reported a total flight time of 17,500 flight hours, with 2,000 hours in single-engine airplanes and 1,000 hours in the Grumman G-164A. His last FAA first-class medical certificate was issued on September 9, 2005. A postaccident examination of the engine by an FAA inspector revealed that the supercharger impeller had incurred "severe impingement damage" to the leading edges on the face of the impeller. There was, however, no evidence of any contact between the impeller and the accessory case. Closer examination revealed that the throat that lead to the impeller also exhibited "severe impingement damage" or "peening." Examination of the carburetor revealed that it also received impingement damage to the bottom of the throttle valves, and the center partition of the base of the carburetor. An external examination of the carburetor venturis and air path did not reveal any evidence of breakage or missing components, and the intake screen, which was upstream of the discovered damage, was still in-place and was not compromised. According to FAA and maintenance records, the airplane was manufactured in 1976. The airplane's most recent annual inspection was completed on March 10, 2006. At the time of the inspection, the airplane had accrued 3,504.6 total hours of operation. At the time of the accident the engine had accrued 899 hours of operation since its most recent overhaul. In addition, the last maintenance performed on the engine occurred 10.9 hours prior to the accident. A weather observation taken about 9 minutes after the accident at Millville Municipal Airport (MIV), Millville, New Jersey, located 12 nautical miles southwest of the accident site, recorded the winds as 290 degrees at 6 knots, visibility 9 miles, a few clouds at 3,200 feet, temperature 71 degrees Fahrenheit, dew point 68 degrees Fahrenheit, and an altimeter setting of 29.82 inches of mercury.