Section/division ACCIDENT AND INCIDENT INVESTIGATIONS DIVISION Form Number: CA12-13 SHORT REPORT AND EXECUTIVE SUMMARY
Reference: CA18/2/3/9512 Aircraft Date of ZU-CDU 05 January 2016 Time of Accident 1105Z Registration Accident Aero trike Spirit II (Weight shift Type of Type of Aircraft Training Part 141 aircraft) Operation Commercial Pilot Pilot-in-command Licence Type Age Licence Valid Yes licence 56 Pilot-in-command Flying Hours on 2 000 250 Experience Type Last point of departure Groutville airfield: Kwazulu Natal Province
Next point of intended landing Groutville airfield: Kwazulu Natal Province Location of the accident site with reference to easily defined geographical points (GPS readings if possible) On a sugar cane farm at GPS co-ordinates determined to be S29°13'9.18" E31°26'28.47" at an elevation of 220 feet above mean sea level (AMSL). Meteorological Information Wind speed, 10 knots: Temperature, 23°C: Visibility, 10 kilometres. Number of people on 2 + 0 No. of people injured 2 No. of people killed 0 board Synopsis On Tuesday 05 January 2016, the flight instructor accompanied by the student pilot was conducting a training flight from Groutville airfield when the accident occurred. Before departure they both conducted a pre-flight inspection and all was normal. The instructor “pilot not flying (PNF)” occupied the rear seat, and the student “pilot flying (PF)” occupied the front seat. The aircraft climbed through 300 feet above ground level (AGL) and flew in the direction of the Tugela River located in Stanger area, KwaDukuza. Approximately after 35 minutes flight time, the engine started running rough. The instructor took control of the aircraft and reduced the throttle setting with the intent to minimize the roughness. He then placed the aircraft into a glide attitude whilst searching for a suitable site for a forced landing. During the process, the engine stopped completely. With limited options available, the instructor aimed for a gravel road on a sugar cane farm. The instructor reported that at a height of approximately 10 ft AGL, he gently flared the aircraft. However before touchdown, the aircraft pitched forward causing the nose gear to hit the ground heavily. The aircraft gently rolled to the right and slid for about 40 meters before coming to a complete stop. The aircraft was substantially damaged. The instructor and the student sustained minor injuries. The investigation determined that the engine trouble arose from detonation that made the piston so hot that the rings stuck into the cylinder wall contributing to engine loss of power and subsequent stoppage.
Probable Cause
Unsuccessful forced landing following engine failure in-flight due to detonation.
SRP Date 08 August 2017 Release Date 17 August 2017 CA12-13 01 FEBRUARY 2017 Page 1 of 4
Section/division Accident and Incident Investigations Division Form Number: CA 12-23 AIRCRAFT ACCIDENT REPORT
Name of Owner : Daniel S Name of Operator : Comefly pilot centre Manufacturer : Rainbow Aircraft (PTY) LTD
Model : Aero trike Spirit II Nationality : South African Registration Marks : ZU-CDU Place : On a private farm Date : 05 January 2016 Time : 1105Z
All times given in this report are Co-ordinated Universal Time (UTC) and will be denoted by (Z). South African Standard Time is UTC plus 2 hours.
Purpose of the Investigation:
In terms of Regulation 12.03.1 of the Civil Aviation Regulations (2011) this report was compiled in the interest of the promotion of aviation safety and the reduction of the risk of aviation accidents or incidents and not to establish legal liability.
Disclaimer:
This report is produced without prejudice to the rights of the CAA, which are reserved.
1. FACTUAL INFORMATION:
1.1 History of Flight:
1.1.1 On Tuesday 05 January 2016, the flight instructor accompanied by the student pilot was conducting a training flight from Groutville airfield situated in Ballito, Kwazulu Natal province when the accident happened. The airfield is located alongside the N2 northbound freeway next to Mvoti Shell Ultra-City, approximately two kilometres from the coast, ten minutes from Ballito in an uncontrolled airspace. Visual meteorological conditions (VMC) prevailed at the time leading up to the accident. The fuel on-board at the commencement of the accident flight was 50 litres and the pilot’s weight combined was 300 kg.
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1.1.2 Total weight at take-off was calculated as 342 kg, with a maximum take-off weight 450 kg. The instructor and the student in advance conducted a thorough briefing in preparation for the flight. Before departure, they both conducted a pre-flight inspection and all was normal. Minutes later they boarded the aircraft and fastened their safety harnesses. The instructor “pilot not flying (PNF)” occupied the rear seat, and the student “pilot flying (PF)” occupied the front seat. The engine started without difficulty from which the aircraft took off at about 1035Z. The aircraft climbed through 300 feet above ground level (AGL) and flew in the direction of the Tugela River located in Stanger area, KwaDukuza. Approximately after 35 minutes flight time, the engine started running rough followed by an immense decay in power. The instructor instantly took control of the aircraft and reduced the throttle setting with the intention to minimize the roughness and placed the aircraft in a glide attitude at about 42 knots indicated airspeed (IAS). He then searched for a suitable site for a forced landing. The instructor turned left with the intent to land into wind. However during the ordeal the engine stopped running completely. With limited options available, the instructor chose a gravel road in the vicinity of a sugar cane farm. According to the instructor, at a height of approximately 10 ft AGL, he gently flared the aircraft. Just before touchdown, the aircraft pitched forward, causing the nose gear to hit the ground heavily. The aircraft gently rolled to the right and slid for about 40 meters before coming to a complete stop. The instructor and the student pilot suffered minor scratches and bruising.
1.1.3 The accident occurred during day time condition at GPS co-ordinates determined to be S29°13'9.18" E31°26'28.47" at an elevation of 220 feet AMSL. Attached below is the photograph of the aircraft as found at the accident site.
Figure 1: The aircraft as found at the accident site
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1.2 Investigation Revealed The Following:
1.2.1 The aircraft was recovered to Groutville airfield and a comprehensive engine examination was carried out by the approved person (AP) No 062 in the absence of the investigators. According to the technical report provided, the engine, including heat shrouds, cooling fans and the carburettor sustained impact damage. Inspection on the oil lines, crankcase drain plug, oil pan gasket, valve cover gasket, oil pump gasket, fuel pump gasket, timing case cover and the camshaft bearing seal showed nothing abnormal with no signs of oil leakage. The oil reservoir and then the level in the reservoir indicated normal. The rear piston and cylinder showed signs of heat damage and seizure. The front cylinder and piston were in perfect condition. The piston in question indicated that the seizure resulted from detonation. During detonation, the fuel/air charge explodes rather than burning smoothly. Because of this explosion, the charge exerts a much higher force on the piston and cylinder, leading to increased noise, vibration, and cylinder head temperatures. The heat caused by detonation made the piston so hot that the rings stuck and the piston seized into the cylinder wall. The airframe and the engine had each accumulated a total time in service of about 1 311,1 hours. Since overhaul, new crankshaft and piston were fitted and had accumulated 343.3 total flight hours. The last annual inspection was conducted by the approved person No 062 on 14 December 2015 at 1 270 total time.
2. CONCLUSION:
2.1 Probable Cause/s:
2.1.1 Unsuccessful forced landing following engine failure in-flight due to detonation.
3.1 Contributing factor/s:
3.1.1 Combustion malfunction.
4. SAFETY RECOMMENDATIONS:
3.1 None.
4. APPENDICES:
4.1 Nil.
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