Low-Altitude Maneuvering · NTSB CEN14LA243

HOFFIUS STOWE CHALLENGER II — Attica, IN

1 fatal Low-time pilotLow altitude
DateMay 10, 2014
LocationAttica, IN
AircraftHOFFIUS STOWE CHALLENGER II (amateur-built)
Purpose of flightPersonal
ConditionsDay · Visual Meteorological Cond
Phase / occurrenceManeuvering Collision with terr/obj (non-CFIT)
Pilot age72
Pilot total time235 hrs · Low time
Time in typeUnknown
Fatalities1

Probable cause

The pilot’s failure to maintain adequate airspeed and his exceedance of the airplane’s critical angle-of-attack while maneuvering at low altitude, which led to an aerodynamic stall and loss of control. Contributing to the accident was the installation of an inappropriate airspeed indicator that did not provide airspeed indications near the airplane’s stall speed.

NTSB findings

  • Aircraft-Aircraft oper/perf/capability-Performance/control parameters-Airspeed-Not attained/maintained - C
  • Aircraft-Aircraft oper/perf/capability-Performance/control parameters-Angle of attack-Not attained/maintained - C
  • Personnel issues-Task performance-Use of equip/info-Aircraft control-Pilot - C
  • Aircraft-Aircraft systems-Indicating/recording systems-Indep instrument (clock, etc)-Incorrect use/operation - F

What happened

The private pilot was conducting a personal flight in the amateur-built light sport airplane. The airplane was maneuvering at low altitude before it descended and then impacted the ground. Examination of the airplane revealed no preimpact mechanical failures or malfunctions.

The forward fuselage and right wing were crushed, consistent with a nose-low, right-wing-low impact. The airplane's attitude at impact was consistent with a steep descending right turn that would occur after a stall. Based on the available information, it is likely that the pilot did not maintain adequate airspeed while maneuvering at a low altitude and exceeded the airplane's critical angle-of-attack, which resulted in an aerodynamic stall.

The airspeed indicator was marked for airspeeds from 40 to 340 mph, but the airplane's stall speed was 32 mph, and its maximum speed was 105 mph. The large discrepancy between the airplane's performance capability and the airspeed indicator markings made the airspeed indicator inappropriate for installation in the accident airplane and would not have provided the pilot airspeed information as he neared the stall speed. The lack of appropriate airspeed information due to the inappropriate airspeed indicator likely contributed to the pilot's failure to maintain adequate airspeed and prevent the stall.

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 →