L2017-02 Ultralight aircraft accident in Laajasalo, Helsinki on 30.5.2017

On 30 May 2017 the engine of an Ikarus C42 ultralight aircraft failed over the sea off Helsinki. The engine died and, in spite of repeated attempts, the pilot could not restart it. The pilot managed to transmit a distress call to the duty officer at Helsinki-Malmi airfield, but could not report their exact position because the aircraft had also lost all electrical power. Following this, the pilot and the passenger began to look for a suitable spot for a forced landing. The pilot determined that their best option was to land in Tuurholma park in Laajasalo. Ultimately, the pilot selected a narrow gravel path in the park for the landing spot which he believed they could successfully use. Just then he noticed that there were people walking on the path and, therefore, he immediately made a left turn towards a small grassy area. However, during the landing the left wing hit a tree and tore off of the fuselage. Following this impact the aircraft kept on moving forward and crashed into the ground, left side first, approximately 12 m from the tree. The pilot and the passenger suffered serious injuries in the accident. Assisted by the pilot the passenger managed to get out the aircraft but the pilot himself had to be extracted from the aircraft by rescue personnel. The aircraft was destroyed.

People walking in the park witnessed the occurrence and called the emergency number for help. The Emergency Response Centre (ERC) received several calls reporting the forced landing. For some reason the ERC did not dispatch any rescue units to the site immediately; only doing so later. This delay in the alert resulted in first response units operating at the target for approximately two and a half minutes without the support of rescue units. The investigation could not find the reason for this delay.

At first neither the first response nor the rescue units were aware of the rocket-deployed parachute, i.e. a ballistic parachute rescue system, which was fitted on the aircraft. After being informed of the accident an investigator at the Safety Investigation Authority called the rescue commander for more information. At the same time the investigator realised that the units were unaware of the rocket-deployed parachute, even though markings warning of the system were clearly displayed on the fuselage. The investigator warned them of the danger posed by the rocket cartridge. The rescue commander halted the rescue operation momentarily, until all units at the site were informed of the rocket-deployed parachute. The rescue department marked the spot where the parachute pierces the skin of the fuselage with yellow warning signs and rescue crews were told to keep clear of that spot. It was later discovered that the rocket cartridge had come loose from its fittings inside the fuselage and was pointing in a direction which would probably have made the parachute break through the skin of the fuselage at another spot. Later, the police disposed of the rocket’s propelling charge on site.

The investigation revealed that, during their basic or advanced training, rescue crews receive no systematic training regarding the danger created by ballistic parachute rescue systems in accidents. Such training will be increased during 2018.

The pilot of the accident aircraft knew that a rocket-deployed parachute system was installed on the airplane, but he was not sufficiently knowledgeable of its use and characteristics. Neither had the pilot at any stage considered activating the system during the forced landing. The investigation revealed that pilots and rescue personnel alike know too little about the operating principles, instructions for use and safety precautions for rocket-deployed parachutes. It is estimated that rocket deployed parachute systems are installed in nearly two hundred aircraft used in general and sport aviation in Finland, and the number keeps growing. When pilots lose control of aircraft, rocket-deployed parachutes are designed to safely bring them down to earth. The ballistic parachute system is intended to increase safety in emergencies.

The aircraft had been regularly maintained. The owner was responsible for time-based technical monitoring of the aircraft, and periodic maintenance had been carried out at the proper times. Small repairs had been made between scheduled maintenances. Maintenance had been carried out in accordance with the aircraft and engine manufacturers’ maintenance lists and instructions. However, excessive wear on the carburettors’ float needle valve´s float bracket had not been noticed, which resulted in the breaking of the left carburettor’s float bracket. This caused the engine to fail and die in the air. Attempts to restart the engine failed because of the broken carburettor and the worn starter.

The Safety Investigation Authority issued two recommendations. The first one was issued to the Emergency Response Administration pertaining to their instructions on the potential danger posed by rocket-deployed parachute rescue systems.

The second recommendation was issued to the Finnish Transport Safety Agency, emphasising the importance of training on the use of ballistic parachute systems.

L2017-01 report (in Finnish) (pdf, 2.41 Mt)

 
Published 8.3.2018