NEWDALE, ID, USA
N9022H
Weatherly 620B
After takeoff, the pilot was unable to climb, and the airplane crashed in a field just beyond the runway about 1 minute after becoming airborne. A post-accident examination of the aircraft's engine revealed no mechanical discrepancies. The FAA inspector assigned to the accident, who talked to the pilot, reported that the pilot took off with full fuel and a full hopper load; a gross weight estimate based on data obtained from the FAA, the pilot, and the aircraft manufacturer indicated that the airplane was approximately 1,830 pounds over its maximum certificated gross weight of 4,000 pounds (per the aircraft's FAA type certificate data sheet), and 330 pounds over the maximum takeoff gross weight for restricted-category operations, at takeoff. Density altitude at Idaho Falls, 40 nautical miles from and about 1,500 feet elevation below the accident area, was computed to be approximately 5,800 feet at the time, based on the hourly observation data being reported at the time.
On July 17, 1997, approximately 0550 mountain daylight time, a Weatherly 620B agricultural aerial application aircraft, N9022H, crashed during an attempted takeoff for a 14 CFR 137 aerial application flight approximately 13 miles east of Newdale, Idaho. The commercial pilot of the sinle-seat aircraft was not injured. Visuaul meteorological conditions were reported at Idaho Falls, Idaho (approximately 40 nautical miles southwest of the accident site), and no flight plan had been filed for the local flight. Accident information from the FAA indicated that the aircraft settled onto a field just off the runway after the pilot was unable to gain altitude during the takeoff. According to the FAA's report, the aircraft crashed into the field, tearing off its landing gear and damaging its wings and engine. The pilot did not furnish a written narrative of the event on his NTSB accident report, but indicated that the airplane was airborne for only 1 minute on the accident flight. The pilot indicated on his NTSB accident report, and also to an FAA inspector assigned to the accident, that he thought he may have experienced a cylinder failure in the aircraft's Pratt & Whitney R-985 radial engine; however, a local mechanic who performed a post-accident examination of the engine for the NTSB and FAA reported that he found no mechanical discrepancies with the engine. The FAA inspector assigned to the accident, who talked to the pilot after the accident, reported on his NTSB accident report that the airplane had 93 gallons (558 pounds) fuel on board at takeoff (the aircraft total fuel capacity is 97.5 gallons, with 7.5 gallons unusable; the unusable fuel weight is included in airplane empty weight.) Additional weights for the accident flight were obtained as follows: pilot weight 236 pounds (from FAA medical certificate); hopper capacity 2,000 pounds (from FAA type certificate data sheet); and aircraft empty weight 3,081 pounds (as delivered, according to records on file at Weatherly Aviation Company of Lincoln, California, the aircraft manufacturer; the aircraft was issued its airworthiness certificate on June 14, 1996.) Based on this data, the estimated gross weight of the aircraft at the time of the accident was 5,830 pounds. The aircraft maximum gross weight, according to the FAA type certificate data sheet, is 4,000 pounds, and according to a commercially published civil aircraft guide, the maximum takeoff gross weight for the model 620 for restricted-category operations is 5,500 pounds. The NTSB requested that the pilot provide weight and balance information on the accident aircraft with his NTSB accident report, but the pilot did not furnish the requested information. In its 0547 hourly surface observation, Idaho Falls, which is 4,741 feet above sea level, reported a temperature of 14 degrees C (57 degrees F) and altimeter setting of 29.92 inches Hg. Based on this data, density altitude at Idaho Falls was computed to be approximately 5,800 feet. On the Salt Lake City sectional aeronautical chart, terrain elevation in the reported accident area is approximately 6,100 to 6,200 feet above sea level.
The pilot's inadequate preflight/planning preparation which resulted in the aircraft exceeding the maximum gross weight, and inability to climb. A factor was high density altitude.
Source: NTSB Aviation Accident Database
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