Undetermined · NTSB WPR21FA025

LANCAIR 235 — Cordes Lakes, AZ

2 fatal High-time pilotLow altitude
DateOctober 24, 2020
LocationCordes Lakes, AZ
AircraftLANCAIR 235 (amateur-built)
Purpose of flightPersonal
ConditionsDay · Visual Meteorological Cond
Phase / occurrenceEnroute-cruise Abrupt maneuver
Pilot age34
Pilot total time7,090 hrs · High time
Time in typeUnknown
Fatalities2

Probable cause

The pilot’s exceedance of the airplane’s critical angle of attack during an aerobatic maneuver, which resulted in an aerodynamic stall and spin and a loss of control. Contributing to the accident was the pilot’s lack of aerobatic experience in the accident airplane make and model.

NTSB findings

  • Personnel issues-Task performance-Use of equip/info-Aircraft control-Pilot
  • Aircraft-Aircraft oper/perf/capability-Performance/control parameters-Angle of attack-Not attained/maintained
  • Personnel issues-Task performance-Use of equip/info-Use of equip/system-Pilot
  • Aircraft-Aircraft oper/perf/capability-Performance/control parameters-Pitch control-Not attained/maintained
  • Aircraft-Aircraft oper/perf/capability-Performance/control parameters-Yaw control-Attain/maintain not possible
  • Aircraft-Aircraft oper/perf/capability-Performance/control parameters-Lateral/bank control-Not attained/maintained
  • Personnel issues-Experience/knowledge-Experience/qualifications-(general)-Pilot

What happened

The pilot was conducting a visual flight rules cross-country flight. Data downloaded from the airplane’s avionics showed that, during cruise flight about 17 minutes after takeoff, the pilot executed a left 360° roll. During the maneuver, the airplane descended more than 1,000 ft, and its vertical acceleration increased from -0.7 to 2.9 G. A few seconds after the completion of the roll maneuver, the engine rpm and oil pressure decreased to zero, and the airplane’s attitude, accelerations, and airspeed parameters became unreliable. A friend of the pilot reported that the pilot had recently learned how to perform rolls in a different make and model of airplane, but no further details were available.

Wreckage and impact signatures were consistent with the airplane impacting terrain in an inverted spin. Postaccident examination of the airplane confirmed continuity to all flight control surfaces, and no engine or airframe anomalies were found that would have precluded normal operation. It is likely that the pilot intentionally attempted an aerobatic maneuver, lost airplane control, and exceeded the airplane’s critical angle of attack, which resulted in a stall, a subsequent spin, and an impact with terrain.

The ethanol identified in the pilot’s cavity blood was most likely the result of postmortem production. Therefore, effects from ethanol did not play a role in this accident.

An editorial "what led to it / how to avoid it" analysis for this accident is generated separately and will appear here.

View the official NTSB docket →