Amateur-built CHALLENGER II N824SH accident near Attica, Indiana

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 analysis

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.

Text from the NTSB. Open the NTSB docket for CEN14LA243 for the full record.