A teenage scout was out of the sight of group leaders when he slipped and fell from a coastal cliff in north Wales, an inquest has heard.

Ben Leonard, 16, from Stockport in Greater Manchester, was in Llandudno on an organised trip with the Reddish explorer scouts when he suffered a serious head injury in the fall.

His mother, Jackie Leonard, broke down in tears as she told the coroner’s court in Ruthin: “We just miss him.”

She said the teenager, who had achieved the chief scout’s gold award, received his GCSE results three days before his death and had enrolled to study film studies at a college in Salford. In a statement, she said: “He was a wonderful boy and a fantastic son and brother.”

Ben Leonard. Photograph: North Wales police/PA

David Pojur, an assistant coroner for north Wales, told the jury a group of nine boys, aged between 14 and 18, had camped near Betws-y-Coed on 25 August with the scout leader Sean Glaister and assistant leaders Mary Carr and Gareth Williams.

The group was due to climb Snowdon but Glaister made the decision to go to Llandudno instead because of bad weather, the court heard.

Pojur said that at the seaside resort Carr and Williams walked with eight of the boys through Happy Valley to the Great Orme on the coast.

The court heard Ben and two friends walked more slowly than the rest of the group and took a different path. Pojur said: “The group of three continued on to the Great Orme and we will hear how they were out of sight.”

The court heard Ben and his friends explored the top of the Orme and Ben, who attempted to find a path down to the road below, was seen by witness Philip Taylor.

The coroner said: “He saw Ben standing, edging along a narrow ledge before climbing down to another short step. He saw Ben take another short step, moments later slipping and falling.

“He wasn’t able to regain his footing nor hold on to anything and he fell on to a steep grass bank below.”

An air ambulance attended but Ben died from a serious head injury, Pojur said.

He told jurors they would have to consider how the trip on 26 August 2018 was organised, the training of the scout leaders and their knowledge of the Great Orme, communication and instructions to the boys and between the leaders, and whether risk assessments were done.

The inquest is expected to last four to five days.