Accident Sequence
On Saturday, 12 August 1972, at 0915 MEZ, a Piper PA-22-150 Tri Pacer, registration HB-OTM, departed Altenrhein airfield for a sightseeing flight with three passengers towards the Rhine valley. Upon return, the aircraft entered the landing circuit from the east at approximately 1200 ft/G (365 m/G), with the altimeter set to QFE. At the start of an extended final approach at about 1000 ft/G, the pilot reduced engine power to idle, fully extended the flaps, and initially maintained an approach speed of 80 mph. Approximately 300 m before the runway threshold, the pilot reported moderate gusts that pushed the aircraft slightly right of the approach axis. He attempted to correct and overfly a cornfield preceding the runway. While crossing the cornfield, the aircraft lost height, prompting the pilot to apply power and adjust the elevator to stretch the flight path. Immediately before landing, the aircraft stalled and settled, coming to a stop after a short distance at 0955 MEZ.
Investigation Findings
The pilot held a valid private pilot license with a flap endorsement. The aircraft was airworthy with no pre-existing technical defects; a comparative measurement of the airspeed indicator remained within tolerance. Weight and center of gravity were within prescribed limits. Weather conditions included light haze, remnants of dissolving stratocumulus clouds on the western slopes, horizontal visibility up to 10 km, wind from the northeast at 5 kt (bise tendency), and a ground temperature of 22°C.
The aircraft sustained substantial damage to the landing gear, propeller, and engine. No third-party damage occurred.
Assessment
The pilot misjudged the height and distance to the runway during the landing approach and did not adequately manage approach speed. While attempting to lengthen the final approach at a relatively low speed, he raised the nose too much, decreasing airspeed below the minimum flying speed, which caused the Tri Pacer to stall and impact the ground hard.
The accident is attributable to the pilot approaching the landing runway too low and subsequently falling below minimum flying speed, causing the aircraft to stall.