Accident Overview
On June 6, 2015, about 1258 central daylight time, a Flight Design CTSW light-sport airplane, registration N535CT, conducted a forced landing shortly after departing Haskell Airport (2K9) in Haskell, Oklahoma. The pilot and a passenger sustained minor injuries, and the airplane sustained substantial damage during the off-airport landing.
Flight Details
The airplane was registered to KT Aviation LLC of Wagoner, Oklahoma, and operated by a private individual under 14 Code of Federal Regulations Part 91 as a personal flight. Day visual meteorological conditions prevailed; no flight plan was filed. The flight originated from 2K9 and was destined for Hefner-Easley Airport (H68) in Wagoner, Oklahoma.
Pilot Actions and Engine Events
Earlier that day, the pilot flew from H68 to 2K9, performing a normal preflight inspection with no discrepancies noted and approximately 28 gallons of automotive fuel aboard. After starting the engine at 2K9, the pilot observed normal engine gauges but inadequate charging system output, prompting him to shut down the engine. Following consultation with a mechanic, the engine was restarted around 1245 with normal engine and charging indications.
During the initial climb from 2K9 at an altitude of 500 to 600 feet above ground level, the engine began sputtering. It continued to run but could not sustain altitude. The pilot selected a field for a forced landing. Various throttle settings failed to restore engine power, and the choke was off. The airplane touched down in a muddy field and came to rest inverted.
Examination Findings
An on-scene wreckage examination revealed substantial damage to the fuselage and damage to the landing gear. Fuel quality checks of the onboard fuel and the fuel facility were satisfactory. The wreckage was moved for a post-accident engine examination. No water or debris was found in the gascolator; both carburetor float bowls contained clean fuel. Spark plugs appeared normal, and ignition spark was verified. A test run of the engine showed no problems at idle or during power runs.
The airplane's Electronic Flight Information System (EFIS) and Engine Monitoring System (EMS) were removed for data extraction. The EFIS memory was corrupted and provided no useful data. The EMS contained an eight-minute recording of engine parameters for the accident flight, which showed engine acceleration to high power followed by fluctuations and a reduction in engine RPM.
Weather Conditions
The closest weather reporting station, located at Okmulgee Regional Airport (about 17 miles southwest of the accident site), reported at 1255: wind from 150 degrees at 3 knots, visibility 10 miles, scattered clouds at 4,700 feet agl, temperature 88°F, dew point 70°F, and altimeter setting 30.00 inches of mercury. The carburetor icing probability chart from FAA Special Airworthiness Information Bulletin No. CE-09-35 indicated that the airplane was operating in an area associated with a serious risk of carburetor ice formation at glide power settings.
Additional Information
A full factual report from the NTSB's Vehicle Recorder Division is located in the public docket for this case.