Jihlavan KP 5 ASA N31KP accident near Marana, Arizona

Probable cause

The pilot's failure to maintain an airspeed above stalling speed (Vs) during an emergency landing after takeoff. Contributing to the accident was an inadequate preflight inspection, and the airplane's canopy coming partially open shortly after takeoff.

NTSB analysis

The airplane's canopy partially opened shortly after takeoff, and the pilot elected to return to the airport for landing. When he was about one-half mile from the airport, he inadvertently allowed the airspeed to drop below stall speed (Vs), and the airplane stalled and mushed into the terrain. A postaccident inspection of the latch found it to be fully functional, with no evidence that it would not latch the canopy if the canopy was firmly closed. The latching mechanism is of a spring-loaded self-activating design that automatically slides over the top of a tang attached to the canopy when the canopy is firmly closed by the pilot. The mechanism then remains in the latched position until the pilot moves the release ring into a position that causes the latch to release. The latching mechanism is located about a foot above, and six inches behind, the right shoulder of a pilot sitting in the left seat. In this position the latch is not easily checked visually, thus dictating that the pilot close the canopy firmly, and then push up on the canopy firmly in order to ensure that the latching mechanism has become fully engaged. Discussions with the manufacturer disclosed that since the time that this airplane was manufactured, but prior to this accident, the manufacturer redesigned the airplane canopy latching system. The new design incorporates two latching mechanisms that are located just forward of the pilot on the left and right side fuselage surfaces upon which the canopy rests when closed. The mechanisms are not self-locking, and are instead positive-action latches that must be engaged by the pilot.

Text from the NTSB. Open the NTSB docket for SEA08LA101 for the full record.