Czech Aircraft Works Sportcruiser N524SC accident near Suffolk, Virginia

Probable cause

The pilot's inadequate recovery from a stall and inadvertent spin. Contributing to the accident was the improperly marked airspeed indicator and the airplane manufacturer's improper airspeed information. Also contributing was the instructor's inadequate supervision of the pilot.

NTSB analysis

The recently certificated pilot was receiving a check-out in the light sport airplane. He was performing slow-flight maneuvers, and because the airplane was already configured, the instructor suggested he perform a power-off stall. The pilot reduced power to idle, and as the airspeed decreased, he increased the pitch attitude to induce a stall. At the onset of the stall, the pilot added power, the airplane yawed left, and “snapped" into a tight spin to the left. The instructor announced that she had the flight controls, and the pilot released them. The instructor verbalized her spin recovery control inputs as she performed them, but the airplane continued to spin and lose altitude. The airplane eventually stopped spinning, and during the post-spin dive recovery, the airplane struck trees and terrain, and came to rest inverted.

A postaccident examination of the airplane revealed the airplane's airspeed indicator's color code range markings were inaccurate and did not agree with the information published in the supplied airplane manufacturer's Pilot Operating Handbook (POH). Depending on the configuration of the airplane, the difference between the published indicated airspeed and the published calibrated airspeeds was as much as 20 knots. The indicated airspeed is an important value for the pilot as it directly indicates stall speed and various airframe structurally limited speeds, regardless of density altitude. If the pilot is receiving inaccurate information from the airspeed indicator, the airplane may stall at a higher airspeed than the pilot is anticipating.

The airplane also experienced a previous accident in which the improperly marked airspeed indicator contributed to the accident. While the airplane manufacturer agreed to make changes to the POH after that accident, those changes were not complete and the accident report was not published prior to this accident.

Text from the NTSB. Open the NTSB docket for ERA10LA098 for the full record.