Weather (Other) · NTSB WPR12FA378
AIRCRAFT MFG & DEVELOPMENT CO CH 2000 — Nephi, UT
| Date | August 30, 2012 |
| Location | Nephi, UT |
| Aircraft | AIRCRAFT MFG & DEVELOPMENT CO CH 2000 |
| Purpose of flight | Instructional |
| Conditions | Day · Visual Meteorological Cond |
| Phase / occurrence | Approach-VFR pattern downwind Windshear or thunderstorm |
| Pilot age | 59 |
| Pilot total time | 94 hrs · Student / very low time |
| Time in type | Unknown |
| Fatalities | 2 |
Probable cause
NTSB findings
- Aircraft-Aircraft oper/perf/capability-Aircraft capability-Climb capability-Capability exceeded - C
- Personnel issues-Task performance-Use of equip/info-Aircraft control-Pilot - C
- Environmental issues-Conditions/weather/phenomena-Convective weather-Thunderstorm-Contributed to outcome
- Environmental issues-Conditions/weather/phenomena-Wind-Microburst-Effect on operation
What happened
Witnesses observed the airplane operating in the airport traffic pattern. As the airplane turned from a crosswind to a downwind leg, witnesses estimated that the airplane was about 150 feet above ground level at a slow speed when it suddenly pitched downward and descended into the ground. Witnesses further stated that at the time of the accident, thunderstorms with strong wind, heavy rain, and lightning were arriving in the area.
A regional radar mosaic for about the time of the accident depicted several scattered weather echoes with one defined cell of moderate-to-strong intensity just over the accident site. Archived lightning data for the time revealed seven in-cloud and cloud-to-ground lightning flashes within a 50-mile radius of the accident site; however, no cloud-to-ground lightning strikes were detected within 15 miles. The detection of lightning confirmed the presence of a cumulonimbus cloud in the area.
Wreckage and impact signatures were consistent with a right-wing-low and nose-low impact. Postaccident examination of the airframe, flight control system, and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. Based on the witness observations and recorded weather data, it is likely that, as a result of the approaching thunderstorm, the airplane encountered a microburst or downdraft that exceeded the airplane's climb performance and resulted in a loss of airplane control.