Covering form of preliminary or final report

Date of event:	2022.10.24
Incident number:	CZ-22-1204
Report:	Final report
Place of event:	Field near Vlčkovice v Podkrkonoší
Registration mark:	Air accident
Weight category MTOM::	<2250 kg
Type of operation:	Recreational and sport aviation
Plane / SFM:	Sports flying machine
Type of plane / SFM:	TL2000 STING
Health effects of event:	The fatal injuries
PDF document:

Description:

SUMMARY

Synopsis

On 24 October 2022, AAII received a notification of a UL TL2000 Sting aircraft accident in a field near the village of Vlčkovice in Podkrkonoší. During a check flight, the UL aeroplane went into a spin, which the pilot failed to escape. The UL aircraft crashed on the field and caught fire. The pilot and another person on board died.

About the flight

Take-off was from LKHK and the flight continued in the direction N to NE. The UL aircraft climbed to an altitude of 3 400 ft MSL and the airspeed was around 100 kt GS. At 12:11, the flight began a gradual deceleration to a speed of 62 kt GS at 12:12:16. The UL aircraft was at this speed for 23 seconds. During this time, the stall warning system with which the UL aircraft was equipped was probably being tested. At the same time, the UL aircraft was descending from an altitude of 3,400 ft to 2,675 ft. After this time there was a brief increase in speed to 85 kt GS. This speed increase occurred within 3 to 4 seconds. This change in GS cannot be explained by a sudden gust, change in wind direction and wind speed, but must have been deliberately caused by the pilot controlling the aircraft by increasing power to the powerplant. This increase in speed was accompanied by a stop of the descent. During the subsequent phase, when the aircraft was not losing altitude, the airspeed slowed again within 10 seconds to 50 kt GS at 12:12:52. Subsequently, there was a rapid decrease in airspeed and the UL aircraft began to lose altitude. At the same time, the direction of flight changed dramatically by about 80° to the right. From the flight direction plot (Figure 5 in Chapter 1.1 in the final report) it is clear that the UL aircraft then rotated, thus being in a spin which could not be escaped. From the finding of evidence on the ground, it is clear that only a stop of rotation was achieved.

Critical phase of flight

The critical phase of the flight occurred at 12:12:52 when there was an apparent loss of control of the UL aircraft, which was manifested by a loss of altitude and airspeed. This phase of flight was preceded by a flight at minimum speed. The meteorological conditions at the scene probably made piloting difficult due to the possible hiding of the natural horizon by clouds and strong gusty winds.

Pilot

The pilot's documentation records show that the UL pilot had a total of 609 hours of flight time on various types of Sports flying devices, 180 of which were on type. Therefore, according to the manufacturer's representative, he had sufficient experience in flying the type, which corresponded to his position in the company - test pilot. Despite his relatively large experience in piloting many types of SFD´s and correctly resolving several emergency situations during power unit malfunction, he had no practical experience in performing spins. Although the UL airplane crashed into a spin at approximately 500 m AGL, the pilot did not attempt to resolve the critical situation by activating a fully functional and operational ballistic parachute rescue system. The broken control stick indicates that the pilot was controlling the UL aircraft until the moment of impact.

UL Aircraft

Examination of the wreckage of the UL aircraft showed that it had arrived at the site intact. Inspection did not confirm a technical failure; all controls were operational at the time of impact. The damage to the steering components was caused only by the destruction on impact and subsequently by the high temperature of the fire that resulted from the impact of the UL aircraft. According to the witness's testimony, the UL airplane's propulsion unit was functioning at the time of the crash and nothing fell off the UL airplane, nor was there any smoke coming from the UL airplane. The functioning of the propulsion unit is also confirmed by the breakage of individual propeller blades and their position around the wreckage at impact site.

Conclusions/Causes

The cause of the accident was the loss of control of the UL aircraft at low speed, followed by a spin.

 

Attached final report in PDF file is in original Czech language.