Covering form of preliminary or final report
| Date of event : | 2023-09-12 |
| Incident number : | CZ-23-1075 |
| Report : | Final report |
| Place of event : | SLZ field LKMIST |
| Registration mark : | Accident |
| Weight category MTOM: : | <2250 kg |
| Type of operation : | Recreational and sport aviation |
| Plane / SFM : | Sports flying machines |
| Type of plane / SFM : | Powered paraglider PAV 2 |
| Health effects of event : | The fatal injuries |
| PDF document : | 
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Description:
SUMMARY
Synopsis
On 12 September 2023, the AAII was notified of an air accident of the PAV 2 powered paraglider (PPG) at the SLZ field MÍSTEK (LKMIST). The pilot planned to carry out a recreational flight to the area at the foot of Lysá mountain. He used about half of RWY 16 at LKMIST for take-off and after lift-off, he was climbing in the direction of the runway to the altitude of about 25 m AGL. After an overflight of the southern edge of the SLZ field, the PPG went into a right steep spiral dive. The powered tricycle hit the ground with its front wheel and the paraglider canopy fell on shrub tops. The pilot succumbed to his multiple injuries despite timely professional resuscitation at the accident site. The PPG was damaged heavily.
Factual Information
It is clear from the analysis of the 25-second video (of low quality) that after a 13-second run-up, the PPG lifted off with a subsequent 8-second climb in the direction of RWY 16 at LKMIST. At the altitude of 25 m AGL, the PPG entered a sharp right spiral dive. The PPG changed direction by about 180° and after 4 seconds, hit the ground.
The position of pilot’s arms captured on the video suggests improper handling of the PG control levers during the take-off phase.
Analyses
Aircraft
The powered paraglider was not airworthy and was operated without any statutory insurance coverage. The last technical inspection of the PPG was performed by an authorised entity in January 2017. The PPG was operated for four years without a technical inspection. During this time, the operator replaced the power unit and made minor modifications to the landing gear. The overall condition of the PPG corresponded to operation without adequate technical maintenance and regular technical inspections. It was ascertained on the basis of calculation that the MTOW of the powered paraglider was exceeded by 42.5 kg, i.e. by 28.9%. Due to that, its flight characteristics were changed in terms of increased responsiveness to external factors and control inputs. With exceeded MTOW, the PG concerned can be more easily pulled over and brought to a crash by control inputs.
The technical inspection, performance of essential expert examinations and analyses, including the assessment of the technical condition of the critical parts of the powered paraglider discovered a proof of the technical defect that caused the loss of PPG manoeuvrability.
It is very likely that an unsecured element of the exhaust system (middle silencer) was released during the flight, fell into the propeller and was subsequently thrown away in the direction of flight. The middle silencer flew through the left upper part of the propeller protective frame, where it left an abrasion mark. Furthermore, it came into contact with the canopy cords near their left free ends. In the process, the left steering line, the left outer suspension line “D” and the middle suspension line “A” were severed. As a result, about 12 canopy chambers were deformed and the canopy geometry was fundamentally changed. PG has thus become uncontrollable.
The specific damage to the ends of all the blades of the three-blade propeller confirms the fact that the power unit was functional and operative before the accident.
During an on-site inspection of the accident site and subsequent technical examination of the PPG wreckage, it was determined that a technical failure related to neglected maintenance was the contributing cause of the air accident. The exhaust middle silencer was not secured against release in accordance with the applicable technical regulation. The releasing of the middle silencer clamping must have been gradual. With adequate pre-flight checks, the fault would have been detected in time.
The powered paraglider was damaged heavily by forces exerted when it crashed against the ground at a big angle with a minimal forward movement.
Meteorological Conditions
The meteorological conditions were suitable for the flight. The flight was carried out under optimal weather conditions. Weak surface wind and good visibility did not impair the PPG piloting.
The pilot and the event flight.
The pilot had held a PL pilot licence for about 8 years, but was not qualified to fly with PPG. He flew his own Sport flying device, but the Commission was unable to trace his total hours flown. During the event flight, the PG was overloaded, which resulted in its altered flight characteristics. PG was fully trimmed (slowed down). The pilot was applying disproportionate braking to the PPG throughout the take-off until the accident. The pilot did not react to the apparent canopy deformation, which is confirmed by the fact that he had both control levers retracted until an impact with the ground. This is indicative of the lack of basic piloting skills that are acquired in instructor-led PPG pilot training.
Critical Situation Origin
The pilot took off from the SLZ field in optimal weather conditions. Shortly after take-off, at an altitude of about 25 m, the pilot lost control and the PPG crashed into the ground in a sharp right spiral. The Commission’s investigation determined that the middle silencer had come loose from the exhaust silencer, causing damage to the propeller and severing some of the cords on the left half of the canopy. As a result, the left half of the canopy was deformed and its flight characteristics changed. The PPG went into a right sharp spiral spontaneously and having turned about 180°, hit the ground. The pilot aggravated the critical situation by not reacting properly and leaving the right control lever heavily retracted.
Conclusions/Causes
The cause of the air accident was the loss of control of the PPG shortly after take-off due to the breakage of the steering and suspension lines by a loose component of the power unit.
Given the cause of the incident, the AAII issues no safety recommendation.
Attached final report in PDF file is in original Czech language.