The group realised one of the party was missing when it reached Ffynnon Llugwy. Photo: Philip Halling CC-BY-SA-2.0

Mountain rescuers were called out to find a missing schoolboy who made the descent of a Snowdonia mountain by the seat of his pants.

Ogwen Valley Mountain Rescue Organisation was called out on Wednesday evening after a party from a religious school in London realised they had left one of the pupils behind.

The boy was part of a large school group who were spending a week in north Wales.

The 10 teenage boys were led up Pen yr Ole Wen by one of their religious leaders before tackling Carnedd Dafydd and Carnedd Llewelyn in good weather.

Chris Lloyd of the OVMRO said the group made its way down to Ffynnon Llugwy before realising there were only nine plus the leader.

He said: “Eight of the boys continued down the tarmac road to the A5 to meet up with others from the school group who had been on Y Garn.” The leader and another boy made their way back up to Cwm Llugwy.

“Despite best efforts, they could not locate the straggler, so mountain rescue was requested at about 8.30pm. The North Wales Police helicopter overflew the area but without success,” Mr Lloyd said.

He said four team members in a hasty party made their way up the cwm, passing two rucksacks abandoned by the leader and schoolboy.

Mr Lloyd said: “A couple of hearty shouts by the hasty team alerted the straggler, who was able to attract attention.

“His white school shirt stood out clearly against the crags and screes which he had descended.

“Three members made their way across to the young man who was unharmed though daunted by his descent route.

“Most of his steep decent must have been on his backside, as the seat of his pants was AWOL.”

He said the fourth team member went to join up with the leader and schoolboy.

“All were safely reunited at the team Land Rover and then brought to Oggie Base for a debrief and refreshments,” he added.

Earlier that day, the Ogwen Valley team was called out to rescue three sheep stuck on a crag near the Braich Ty Du ridge on the lower slopes of Pen yr Ole Wen.

Mr Lloyd said: “Overnight, two had vacated the ledge leaving only one live sheep requiring the resources and expertise of the team members.

“The four-man rescue party and one spotter from the A5 road were successful in ‘bagging’ the sheep and lowering it to new pastures.”

On Friday, the team was called out after a walker fell and injured his head.

The 40-year-old from Oxford was attempting the 14 Welsh 3,000-footers and was coming down the scree path next to Bristly Ridge on Glyder Fach when he tumbled 15m (50ft).

Mr Lloyd said: “His four colleagues who were slightly behind were shocked to see the deep lacerations on the head of the casualty and called for mountain rescue.

“With the history of the incident, the team leader requested the assistance of 22 Squadron, RAF Valley. They were able to fly straight to the incident site, as team members gathered at Oggie Base.

“After a very thorough examination of the casualty, he was winched aboard and was met by the trauma team at Bangor hospital.

“Fortunately, his injuries are not as serious as the potential after a fall on that path.”