History of Flight
On June 18, 2014, at approximately 1930 eastern daylight time, a Grumman Aircraft G-164B, registration N891JC, impacted the ground during a forced landing shortly after takeoff near Chorman Airport (D74) in Farmington, Delaware. The aircraft was operated by Chorman Spraying, LLC as an aerial application flight. The commercial pilot received minor injuries, and the aircraft sustained substantial damage to the fuselage and empennage. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight, which was conducted under 14 CFR Part 137. The flight was originating at the time of the accident.
According to the pilot, he had flown the aircraft in the morning and returned to the airport around 1900 to load the hopper tank with insecticide and water for a flight to a nearby watermelon farm. After loading and fueling, he taxied out, performed pre-takeoff checks, and departed to the north. Following departure, he maneuvered to climb to the right of the runway's extended centerline to avoid overflying a residence. He reported reducing manifold pressure to 32 inches and propeller speed to about 2,000 rpm. At approximately 150 feet above ground level, he commanded a slight left bank toward the west, and the airplane immediately began to "settle." The pilot leveled the wings, but the airplane initiated an uncommanded right bank "similar to entering a stall." He attempted to pull the product dump handle but inadvertently activated the spray handle. A second attempt to dump was unsuccessful due to close proximity to the ground. The airplane subsequently impacted a field, nosed over, and came to rest inverted.
Pilot Information
The pilot held a commercial pilot certificate with single-engine land, multiengine land, and instrument airplane ratings, as well as a flight instructor certificate for single- and multiengine land and instrument airplane. His most recent second-class medical certificate was issued on October 24, 2013. He reported 2,306 total flight hours, including 573 hours in the accident make and model.
Aircraft Information
The single-engine, tailwheel-equipped biplane was manufactured in 1977 and powered by a Pratt and Whitney radial engine with 10,125 hours total time and 553.53 hours since major overhaul. The most recent annual inspection was completed on May 8, 2014.
Meteorological Information
A weather observation at 1854 from Sussex County Airport (GED), 15 miles southeast of the accident location, recorded wind from 210° at 8 knots, visibility 10 miles, clear skies, temperature 33°C, dew point 20°C, and barometric pressure 29.96 inches of mercury. Density altitude was approximately 2,100 feet.
Airport Information
Chorman Airport was a privately owned, uncontrolled field with a single runway (16/34) measuring 3,588 feet long and 37 feet wide. The runway surface was in poor condition; airport elevation was 66 feet above mean sea level.
Wreckage and Impact Information
Post-recovery examination by an FAA inspector revealed substantial damage to the fuselage, vertical stabilizer, and rudder. Hand rotation of the engine via the propeller hub showed continuity through the engine and thumb compression on some cylinders, but the supercharger impeller did not rotate.
Test and Research
An NTSB-supervised engine examination noted minimal external damage. Hand rotation with a turning bar revealed internal binding and a non-rotating impeller. Thumb compression was observed on all cylinders. Disassembly found an intermediate gear with three impact-sheared teeth and no other damage, and no evidence of preimpact anomalies that would have precluded normal operation.
Additional Information
The pilot and operator reported that the aircraft was fueled with 80 gallons of fuel and had 250 gallons of product in the forward hopper tank before departure. The actual weight at the time of the accident was about 6,934 pounds; maximum gross weight was 7,564 pounds. Density altitude calculations, based on FAA materials, indicated that at 91°F and approximately sea level pressure altitude, climb rate would have been reduced by about 20%.