VFR into IMC · NTSB WPR15FA166
CESSNA 210F — Pleasanton, CA
| Date | May 21, 2015 |
| Location | Pleasanton, CA |
| Aircraft | CESSNA 210F |
| Purpose of flight | Personal |
| Conditions | Day · Instrument Meteorological Cond |
| Phase / occurrence | Enroute-cruise VFR encounter with IMC |
| Pilot age | 66 |
| Pilot total time | 1,232 hrs · Experienced |
| Time in type | Unknown |
| Fatalities | 1 |
Probable cause
NTSB findings
- Personnel issues-Action/decision-Info processing/decision-Decision making/judgment-Pilot - C
- Aircraft-Aircraft oper/perf/capability-Performance/control parameters-Altitude-Not attained/maintained - C
- Environmental issues-Conditions/weather/phenomena-Ceiling/visibility/precip-Below VFR minima-Effect on operation
- Environmental issues-Physical environment-Terrain-Mountainous/hilly terrain-Not specified
What happened
Before beginning the cross-county flight under visual flight rules (VFR), the pilot received a weather briefing that reported VFR conditions at the departure and destination airports but included an airmen's meteorological information notice for instrument flight rules (IFR) conditions along the route of flight. About 8 minutes after departure, recorded radar data showed the airplane's altitude varying between 321 and 635 ft above ground level (agl) for about 1.5 minutes before the impact. Until about 30 seconds before impact, the airplane was tracking south on course along a valley, but it then began to deviate west toward rising terrain. The airplane then began a slow, descending right turn. The last recorded radar target showed the airplane about 0.2 miles from the accident site, at an altitude of about 410 ft agl.
A postaccident examination of the airframe and engine revealed no evidence of preimpact mechanical malfunctions or failures that would have precluded normal operation. A review of weather observations and satellite imagery indicated that IFR conditions prevailed in the vicinity of the accident site due to low clouds and restricted visibility. It is likely that the pilot was varying his altitude to remain clear of the clouds and subsequently entered an area where continued flight on course was not possible and initiated a right turn. During the turn, the airplane collided with rising terrain.