Cat. 2 investigation report: simplified-format report, adapted to the circumstances of the occurrence and the investigation stakes.
After checking in for flight LY326 with Alysia (EL AL subcontractor), the passenger kept his own electrical wheelchair in order to go to the boarding zone. Shortly before boarding the aeroplane, a Samsic agent (ADP subcontractor) installed him in a transfer wheelchair. The passenger folded his wheelchair himself and handed it to an EL AL security agent.
Following a lack of understanding and despite the instructions given by the Alysia agents during the check-in and in the departure lounge, the passenger supposed that one of the agents with whom he was dealing was going to remove the battery and that he did not have to do it. The wheelchair was then subject to checks which are not designed to identify the battery. The loading supervisor then took charge of the wheelchair but did not identify that the battery was still in place: he supposed that the red canvas pouch attached to the wheelchair contained the battery without being able to confirm this. He did not identify or did not know that the passenger should have carried the battery in the cabin.
After the wheelchair had been secured in the aft hold of the aeroplane, a short circuit occurred in the wheelchair’s electrical system for unknown reasons. The battery, still connected, sustained this short circuit which resulted in incipient combustion. The battery was in immediate contact with the combustion zone which could have created thermal runaway inside the battery.
Following the incipient combustion, a warning was activated in the cockpit. The crew then complied with the procedures, declared an emergency situation and constantly analysed the situation to adapt their actions until all the passengers and crew members had safely evacuated the plane.