THE REPUBLIC OF CROATIA Air, Maritime and Railway Traffic Accident Investigation Agency Air Traffic Accident Investigation Department CLASS: 343-08/17-03/03 No: 699-04/1-18-15 Zagreb, 8 th June 2018 F I N A L R E P O R T ON SERIOUS INCIDENT OF THE AIRCRAFT SR-20, REGISTRATION D-ELLT, WHICH OCCURED ON MAY 20 2017, AT ZADAR AIRPORT AIN04-FR-03
PUBLICATION OF REPORT AND COPYRIGHT This report has been made and published by the Air, Maritime and Railway Traffic Accident Investigation Agency (hereinafter: AIA) pursuant to Article 6 section 1 and 2 of the Act on Establishment of the Air, Maritime and Railway Traffic Accident Investigation Agency (Official Gazette no 54/13), Article 7 Section 1 and 2 of the Statute of the Air, Maritime and Railway Traffic Accident Investigation Agency, Article 16 of the Regulation (EU) No 996/2010 of the European Parliament and of the Council on the Investigation and Prevention of Accidents and Incidents in Civil Aviation, provisions of the Air Traffic Act (Official Gazette no 69/09, 84/11, 54/13, 127/13 and 92/14), and pursuant Chapter 6 of the Annex 13 ICAO. This report or any part thereof shall not be produced, reproduced or transmitted in any form or in any manner, without the express written consent of AIA. This report may be freely used for educational purposes only. For all further information contact AIA. The aim of the investigation relating to safety is in no case determination of guilt or liability. Investigations are independent and separate from court or administrative proceedings and should not prejudice determination of guilt or liability of individuals. The final report cannot be used as evidence in court proceedings whose aim is determining civil or criminal liability of individuals. AIN04-FR-03 Page: 2/17
CONTENT SUMMARY...4 1. FACTS AND INFORMATION...4 1.1. FLIGHT INFORMATION... 4 1.2. INJURIES... 5 1.3. DAMAGE TO THE AIRCRAFT... 5 1.4 OTHER DAMAGE... 8 1.5 PERSONAL INFORMATION... 8 1.6 AIRCRAFT INFORMATION... 8 1.6.1 Aircraft general information... 8 1.6.2 Description of the aircraft... 8 1.6.3 Aircraft Characteristics... 9 1.6.4 Other information... 9 1.7 METEOROLOGICAL INFORMATION... 9 1.8 AIRPORT INFORMATION... 10 1.8.1 Zadar Airport (LDZD)... 10 1.9 FLIGHT DATA RECORDERS... 10 1.10 IMPACT AND WRECKAGE INFORMATION... 10 1.11 MEDICAL INFORMATION... 11 1.12 TESTING AND INVESTIGATION... 11 1.13 ADDITIONAL INFORMATION... 12 2. ANALYSIS... 12 3. CONCLUSION... 12 3.1 FINDINGS... 12 3.2. CAUSES... 13 3.2.1. DIRECT CAUSE:... 13 3.2.2. CONTRIBUTING FACTORS:... 13 4. SAFETY RECOMMENDATION... 13 5. APPENDICES... 14 5.1 Appendix 1...15 5.2 Appendix 2 17 AIN04-FR-03 Page: 3/17
OCCURRENCE INFORMATION Type of the occurrence: Serious incident Date: 20 May 2017 Time: 13:12 LT Place: Zadar Airport Type of the aircraft: Aeroplane Registration: D-ELLT Manufacturer / model: Cirrus Aircraft / SR-20 Operator: Private Number of persons aboard: 2 (pilot and 1 passenger) Damage to the aircraft: Minor INVESTIGATION The Air, Maritime and Railway Traffic Accident Investigation Agency (AIA) received information on the serious incident the same day from Zadar Airport and the owner of the aircraft through the Aviation Safety Report. Upon completion of the investigation, the Air, Maritime and Railway Traffic Accident Investigation Agency issued this. SUMMARY On 20 May 2017 around 13:12 LT at Zadar Airport (LDZD), during taxiing towards the runway, the aircraft Cirrus SR-20, registration D-ELLT, turned from the taxiway and struck the edge light with the propeller. There were two persons aboard pilot and 1 passenger. There were no injured persons in this serious incident. Minor material damage of the aircraft and airport signalization occurred. The direct cause of this incident was aircraft turning from the taxiway due to the malfunction of the right wheel brake. The investigation concluded that the malfunction occurred due to omissions during aircraft maintenance. AIA issued no safety recommendation. 1. FACTS AND INFORMATION 1.1. FLIGHT INFORMATION The flight of the D-ELLT aircraft on 20 May 2017 started with taxiing from the general aviation apron of Zadar Airport (LDZD). The aircraft started from the parking space, taxiing through taxiway L towards the holding point position for runway 22. In an effort to keep the correct direction of movement, the pilot pressed the right brake, however the aircraft did not react and continued moving to the left. After the pilot pressed both brakes, the aircraft stopped approximately 6 meters away from the taxiway (Picture 1) on the grassy part of the apron. AIN04-FR-03 Page: 4/17
Picture 1. The aircraft stop position after turning from the taxiway marked L The pilot states that after the initial moving of the aircraft and starting to taxi from the general aviation apron, problem appeared with directing the aircraft in the desired direction. At that moment, the right brake of the aircraft did not react to the pressure of the pilot. 1.2. INJURIES Injuries Crew Passengers Others fatal 0 0 0 serious 0 0 0 minor/none 1 1 0 1.3. DAMAGE TO THE AIRCRAFT During this serious incident propeller strike to the runway edge light occurred, minor damage was caused to the aircraft. AIN04-FR-03 Page: 5/17
- Two propeller blades were damaged (Picture 2). - The nose wheel cover was damaged (Picture 3). Picture 2. Damaged propeller blade AIN04-FR-03 Page: 6/17
Picture 3. -Damage of the nose wheel cover AIN04-FR-03 Page: 7/17
1.4 OTHER DAMAGE At the site of the serious incident the runway edge light was damaged. 1.5 PERSONAL INFORMATION Two persons were aboard the aircraft. Pilot: Male person, German citizen, born in 1959, holds a valid PPL licence. Passenger: Female person, German citizen, born in 1964. 1.6 AIRCRAFT INFORMATION 1.6.1 Aircraft general information Registration: D-ELLT Manufacturer: Cirrus Aircraft Type: SR-20 Serial number: 1011 Year of manufacture: 1999 Total flight hours: 1512.62 1.6.2 Description of the aircraft Cirrus SR-20 aircraft is a low-wing single engine aircraft of composite construction, (Picture 4). The fuselage of the aircraft is not pressurized. The landing gear in non retractable, type tricycle with a differential aircraft control system for taxiing on the ground. The aircraft controls include the possibility of electrical adjustment (trimmer) with the corresponding indication. Tail surfaces consist of classic horizontal and vertical stabilizer, elevator and rudder. The powerplant consists of a Continental IO-360 ES engine of 200 hp. The fuel tanks are located in the wings of the aircraft. Since during initial production the aircraft did not meet the standards associated with the spin manouvre, there is a parachute in the fuselage for the entire aircraft that can be activated in the event of an emergency. This sports aircraft is characterized by a specific wing profile, and so called glass cockpit system for indicating all parameters. Furthermore, what makes this aircraft attractive is the side stick design of control command. Given the above technical details, there is a clear link between the designs of Cirrus SR-20 aircraft and commercial aircrafts. For that reason, some pilot schools use this aircraft for pilot training. AIN04-FR-03 Page: 8/17
Picture 4. Aircraft Cirrus SR-20 1.6.3 Aircraft Characteristics Number of seats: Length: Range: Height: Weight of empty aircraft: Maximum take-off weight: Stall Speed: Maximum flight altitude: Maximum cruise speed: 4 or 5 (depending on aircraft configuration) 7.92 m 11.68 m 2.72 m 964 kg 1361 kg 104 km/h (flaps out) 5300 m 287 km/h 1.6.4 Other information The owner and operator of the D-ELLT aircraft is a private German citizen. The aircraft is registered in Germany. 1.7 METEOROLOGICAL INFORMATION Meteorological conditions did not affect the serious incident that is the subject of this report. AIN04-FR-03 Page: 9/17
1.8 AIRPORT INFORMATION 1.8.1 Zadar Airport (LDZD) Zadar Airport (ICAO code: LDZD, IATA code: ZAD) is located in the middle of the Dalmatian coast in Zemunik Donji. At the airport, civilian and military air traffic takes place. The airport operator is the company Zadar Airport d.o.o. During the tourist season, the commercial passenger traffic of Ryanair Ltd, and other charter operators represents a significant percentage of the traffic. The airport infrastructure consists of two runways, several taxiways and apron for parking of the aircraft. Considering the equipment of the runways, the airport is characterized by a high percentage of openness throughout the year regardless of meteorological conditions. 1.9 FLIGHT DATA RECORDERS The aircraft was not equipped with the flight data recorder or the cockpit voice recorder. 1.10 IMPACT AND WRECKAGE INFORMATION The site of the serious incident is located at the civil part of the Zadar airport on the taxiway marked L (Picture 5). The aircraft turning point from the driving lane marked L Picture 5. Serious incident location marked with red colour AIN04-FR-03 Page: 10/17
1.11 MEDICAL INFORMATION There were no injuries in the serious incident in question therefore the medical assistance was not required. 1.12 TESTING AND INVESTIGATION The Cirrus SR-20 aircraft is equipped with so-called differential aircraft control system for taxiing on the ground. Namely, the aircraft is directed using differential braking for ground steering and there is no built-in nose wheel control system. Improper operation of the braking system can partially or completely disable aircraft control during taxiing on the ground. Due to the nature of the incident, inspection of the brake system of the aircraft was performed. The aforementioned inspection was carried out by the company 'Aero standard d.o.o.' for the purposes of investigation of and ordered by AIA. The following was established: - there was a loss of hydraulic fluid from the brake system - a seal which did not comply with the manufacturer's specifications was installed in the brake system of the right-hand wheel Found incorrect seal that was installed Seal of the correct catalogue number M83461/1-224 or MS28775-224 Picture 6. Components of the brake of the right main landing gear after disassembly and comparison of the seals AIN04-FR-03 Page: 11/17
Picture 6 shows the components of the right wheel brakes and the seals which, according to the manufacturer's document Cirrus IPC 12138-00, edition E2, should have be installed in the brake system. It is obvious that the seal that was installed (left seal), was much smaller than the seal specified by the manufacturer (right seal). 1.13 ADDITIONAL INFORMATION Considering the propeller strike on a fixed obstacle it is important to state the following: Documentation of the engine manufacturer Continental, no. M-0, Amendment No.3, Revision Jan. 2017, Chapter 6-5, Section 6-5.1, strictly defines engine maintenance in the event of a propeller strike on the fixed obstacle, in the manner that the engine is completely disassembled into the parts (described in section 1-1.1 of the said manual) for internal parts inspection, and all separate parts, such as bearings, connecting rod nuts and bolts, should be replaced regardless of condition. The above procedure must be performed prior to further flight of the aircraft as the propeller strike on a fixed obstacle may cause damage to the internal parts of the engine which are not immediately visible but further use of the engine may cause engine failure. 2. ANALYSIS By analysing the case, it was established that in the process of maintenance of the aircraft, the incorrect seal of the cylinder brake of the right main landing wheel was installed, which caused the brake to fail. Considering the design of the aircraft, the failure of the brakes caused the aircraft to turn from the taxiway where the aircraft propeller struck the edge light. Given the described course of events and the above-mentioned engine maintenance procedures, it is important to point out that the engine inspection of the subject aircraft was not carried out in the manner described in Chapter 1.13 prior to the further flight of the aircraft. 3. CONCLUSION 3.1 FINDINGS - Meteorological conditions had no influence on this serious incident, - The pilot holds a valid PPL licence, - The maintenance documentation, as well as other documentation of the aircraft, was in order; - The investigation established an omission in maintenance of the subject aircraft installing the incorrect seal in the brake system of the right wheel; - Due to the incomplete sealing of the cylinder brake of the right wheel there was a loss of hydraulic fluid; - After loss of hydraulic fluid in the brake system of the right wheel, the brake on that wheel was no longer in function and the aircraft became uncontrollable when taxiing, - The aircraft uncontrollably turned from the taxiway and struck the signal mark along the edge of the lane, - Damage to the two propeller blades, - Damage to the nose wheel cover, - Damage to the signal light along the edge of the taxiway, - No injuries, AIN04-FR-03 Page: 12/17
- The aircraft left Zadar Airport without engine inspection. 3.2. CAUSES 3.2.1. Direct cause: Loss of aircraft manoeuvrability due to technical malfunction. 3.2.2. Contributing factors: The omission in maintenance of the aircraft, on which occasion the incorrect seal was installed in the brake system of the right wheel. 4. SAFETY RECOMMENDATION In this case, AIA has no safety recommendation. Investigator in charge Dejan Ćurik AIN04-FR-03 Page: 13/17
5. APPENDICES 5.1 APPENDIX 1 COPY OF THE SPARE PARTS CATALOGUE FOR CIRRUS IPC 12138-00, E2 - Copy of certain pages of the spare parts catalogue for Cirrus IPC 12138-00, edition E2, page 1 AIN04-FR-03 Page: 14/17
- Copy of certain pages of the spare parts catalogue for Cirrus IPC 12138-00, edition E2, page 2 AIN04-FR-03 Page: 15/17
5.2 APPENDIX 2 SPARE PARTS CATALOGUE FOR CIRRUS IPC 12138-00, E2 - copy of certain pages of the maintenance manual for engine Continental, no. M-0, Amendment No.3, Revision Jan. 2017 page 1 AIN04-FR-03 Page: 16/17
- copy of certain pages of the maintenance manual for engine Continental, no. M-0, Amendment No.3, Revision Jan. 2017 page 2 AIN04-FR-03 Page: 17/17