Incident Overview
On 12 June 2020, a Reims Aviation S.A. F152 airplane, registered as HB-CXV, was involved in an accident during takeoff from Beromünster airfield (LSZO). The flight was an introductory training flight with a flight instructor and a student pilot. The aircraft sustained heavy damage, and one occupant suffered minor injuries. No third-party damage occurred.
Pre-Flight Preparation
The flight instructor and student met at 15:00 local time and conducted a pre-flight inspection. The aircraft initially had 23 liters of fuel, and an additional 12 liters were added. Due to strong southerly foehn winds, the tailwind component on runway 33 was deemed excessive. The instructor considered using a more powerful aircraft (a Reims Cessna F172), but the student preferred the F152, and they decided to wait for better wind conditions. During the wait, the instructor explained pre-flight procedures, including takeoff distance calculations and the decision points ("gates") for continuing or aborting the takeoff. By evening, the outside temperature had dropped, and wind decreased to about 5 km/h from the southeast, as assessed by the instructor. At around 19:00, a second pre-flight inspection was performed, and no technical defects were noted.
Takeoff and Accident Sequence
Shortly before 19:00, the engine was started, and the aircraft taxied to the holding point of runway 33 for run-up checks. At 19:05, the instructor taxied into takeoff position on runway 33 and checked the windsock, observing a tailwind of about 5 km/h with a slight crosswind from the right. A short-field takeoff was performed, requiring full throttle with brakes set and flaps set to 10°. After releasing the brakes, the instructor slightly raised the nose to aid acceleration. Passing the runway midpoint marker, the indicated airspeed was 35 knots. As the aircraft passed the taxiway near the fuel station, a noticeable nosewheel lightening was felt. Shortly thereafter, the aircraft became airborne but immediately struck its tail on the ground and became airborne again. The instructor attempted to accelerate in ground effect to transition to climb, but acceleration was insufficient and altitude gain minimal. The instructor then executed a forced landing straight ahead in a field. The aircraft first touched down with the main landing gear, then the nose gear, and nosed over. After coming to rest, the instructor opened the student's door first, then exited through the left door. No fire or fluid leaks occurred.
Aircraft and Operational Details
The HB-CXV was a Reims Cessna F152, owned and operated by Flug Betriebs-AG Beromünster. The flight instructor held an EASA ATPL(A) license with 6,793 total flight hours (47:48 on type). The student had no pilot license and no flight hours. The takeoff was conducted on runway 33, a grass surface with a total length of 510 meters, but only the first 400 meters were available for use that day. At takeoff, the aircraft weighed 742 kg, within the maximum takeoff mass of 758 kg, and the center of gravity was within limits. For a short-field takeoff, the aircraft flight manual specified a rotation speed of 50 knots indicated.