Covering form of preliminary or final report
Back| Date of event: | 2020.07.07 |
|---|---|
| Incident number: | CZ-20-0348 |
| Report: | Final report |
| Place of event: | Hodkovice Airport |
| Registration mark: | Accident |
| Weight category MTOM:: | <2250 kg |
| Type of operation: | Recreational and sport aviation |
| Plane / SFM: | Gliders |
| Type of plane / SFM: | ASW-19 B |
| Health effects of event: | Without injury |
| PDF document: |
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Description:
On 7 July 2020, the AAII CZ was notified of an air accident of the ASW-19 B glider at LKHD. According to the initial information, the pilot was landing at high speed. Upon the first contact with the runway, the glider bounced several times. While the glider was bouncing, the canopy got shattered. The glider tail part broke upon the last contact with the ground. The glider stopped about 150 m before the end of the runway. The pilot was not hurt. The glider was damaged to a large extent.
On the same day, the AAII CZ inspectors arrived at the location of the air accident and collected data principal for investigating the air accident causes.
The pilot took off in aerotow from RWY 01 at 12:21 for her third flight on the given type. The towline was released approximately 2 km south of THR RWY 01 where she was trying to find a thermal climb usable for further flight. She failed to find a thermal climb, so at the altitude of 300 m AGL, she decided to return to the departure airport. She reported to the Hodkovice RADIO frequency and started performing a landing manoeuvre on RWY 01.
According to data obtained from the glider recording device and witnesses’ testimonies, the glider first touched the ground on RWY 01 approx. 170 m behind its THR.
The glider roughly touched the runway for the second time approx. 450 m behind RWY 01 THR and bounced 295 m. When examining the runway, the Commission found a 3 m long groove. Small pieces of the glider laminate skin were also found near the groove.
At the place of the third contact with the runway, the Commission also found two grooves approximately 2 m long. This contact with the runway was so strong that the canopy got shattered and the tail part broke after having turned 90 degrees to the left. The tail shoe was found near one of the two grooves. Starting from this contact with the ground, the glider was sliding on RWY 01 for some 90 m until full stop. There were pieces of laminate from the glider front part and tail part and pieces of organic glass from the canopy along all this route.
The fuselage front part, the canopy, was damaged and the fuselage tail part was twisted and broken.
Glider Pilot
- Female, 53 years, foreign national.
The ASW-19 B glider is a high-performance self-supporting midwinged laminate single-seater with 15 m wingspan and T-shaped tailplanes. The one-piece cockpit canopy is pressed from organic glass.
Location of the aerodynamic brakes and undercarriage control levers in the glider cabin
Both the control levers, the aerodynamic brakes control lever and the undercarriage control lever, are located on the left-hand side of the pilot cabin.
The location of the undercarriage control lever (“POP” in the figures below) in the fore position – the undercarriage is extended and locked. The lever in the rear position – the undercarriage is retracted and locked.
The location of the aerodynamic brakes control lever (“POA” in the figures below) in the fore position – brakes are retracted. The lever in the rear position – brakes are extended.
POP and POA control and location are identical for the ASW-19 B and ASW-20 types.
In addition, the ASW-20 type is equipped with flaps while the flaps control lever is located on the cabin frame above POP and POA.
The weather at the time of air accident – scattered clouds to cloudy with sporadic rain showers. Daily temperatures from 18 to 22°C. Night temperatures from 10 to 6°C. North-westwind at a speed of 2–6 m/s.
Wreckage and Impact Information
The air accident site was located on RWY 01 approximately 750 m north of the airport reference point. The surface was covered with grass and there were no big bumps.
- She had a SPL private pilot licence issued by Niedersächsische landesbehörde für Straßenbau und Verkehr (Lower Saxony State Authority for Road Construction and Transport) with radiocommunication licence only for VFR and only in German language.
- She held valid LAPL medical certificate.
- She has been flying since 1986, but the number of her total hours flown – 309 hrs 45 min – on various glider types was relatively low. Most frequently, she flew on the ASW-20, on which she had flown about 150 hours.
- On 6 July 2020, she carried out theoretical and practical transition training with an instructor on a new type of glider with two subsequent flights lasting 27 minutes, and 1 hour and 51 minutes, respectively.
- The pilot was performing her third flight on the ASW-19 B type. She was unable to find a thermal climb, and therefore decided to return to the airport at an altitude of about 300 m.
- She announced her intention to land on RWY 01 and began a landing manoeuvre on the said runway. According to witnesses’ statements and the findings in the cabin at the scene of the accident, the glider did not have either the aerodynamic brakes or the undercarriage extended when landing.
- The pilot stated in her statement that she had extended and locked the undercarriage and extended the aerodynamic brakes.
- Since the control levers of the undercarriage and the aerodynamic brakes, respectively, are operated “in the direction against each other”, it is likely that they were confused by the pilot. The pilot therefore retracted the undercarriage instead of releasing the aerodynamic brakes.
- According to the analysis of data obtained from the recording device, the glider was slowing down and descending in a standard manner until 12:34:18.
- At 12:34:20, there was a gradual increase in speed, caused probably by retracting the undercarriage instead of extending the aerodynamic brakes.
- The increase in speed continued until RWY 01 THR was overflown at a speed of 170 kmh-1, that is by 80 km·h-1 faster than the landing speed recommended by the manufacturer: 90 km·h -1.
- The pilot continued the landing manoeuvre. The glider bounced twice during landing, at a distance of about 170 m and about 450 m from RWY 01 THR.
- The impact upon the third contact with the runway shattered the canopy and broke the tail, which was twisted by 90 degrees to the left.
- From the moment of the third contact, the glider was sliding along the runway for about 90 m until its complete stop, at a distance of about 150 m from the end of RWY 01. There was no breakage of the tail part from the glider.
- There were pieces of laminate from the glider front part and tail part and pieces of organic glass from the canopy along all this route.
Technical condition of the glider had no impact on emergence of the air accident. The glider underwent regular annual maintenance, including an airworthiness review on 3 July 2020 with no findings. There had been no defects during the flights preceding the critical event flight.
The weather conditions had no effect on the emergence and development of the air accident.
- She held a SPL private pilot licence with radio licence only for VFR communication and only in German language.
- She held valid LAPL medical certificate.
- She had a relatively small number of overall hours flown on various types of gliders. Most frequently, she flew on the ASW-20 on which she flew about half of her total flight hours.
- The day before the critical flight, she conducted theoretical and practical transition training on ASW-19 B with an instructor, plus performed two separate thermal flights.
- The critical flight was her third flight on ASW-19 B, the first one on the given day.
- She performed approach and landing at speeds higher (see Chart No. 1) than specified in the flight manual.
- The glider bounced twice. The first contact with the ground was only momentary and no parts of the glider were found in its area. A groove and the first small laminate parts were found in the area of the second contact with the ground.
- Two grooves, tail shoe and other laminate parts were found in the area of the third contact with the ground. It was at this point where the canopy was shattered, and the tail part was broken and twisted.
- From the location of the third contact, the glider was sliding down RWY 01 for about 90 m until it came to a complete stop.
- Technical condition of the glider had no impact on emergence of the air accident.
- The weather conditions had no effect on the emergence and development of the air accident.
The cause of the accident was most likely the pilot mistaking the aerodynamic brakes control lever for the undercarriage control lever. As a result, the approach and landing took place at high speed. The pilot did not solve this situation successfully.
Attached final report in PDF file is in original Czech language.