A reminder has been supplied by mountain rescuers on the wisdom of using Ordnance Survey maps
and compasses when venturing onto the hills.
RAF mountain rescuers flew by helicopeter this week in support of the Killin Mountain Resue team after a call-out by a trio lost on local Munro Beinn a' Chroin, near Crianlarich.
The group had been trying to navigate using only a smartphone and were unable to find their way after clouds descended on the peak.
Duty aircrewman Petty Officer Mike Henson revealed that due to the difficulty of rying to find peoepl in such poor visibility, he had landed the chopper on the montainside and continued on foot to find the party, which he was able to do as they had a whistle they could blow.
He noted it was "positive" that the hikers had a whistle and were wearing highly visible walking jackets
However, he added: "It is not a good idea to venture into the mountains, no matter how clear the day, without having a proper map and compass with you - and knowing how to use them.
"It doesn't take much for the weather to close in around you and mobile phone reception can be notoriously fickle."
Petty Officer Henderson noted the group was cold and had been lost for two hours when they were found, with the prospect of a two-hour descent in fading light even if they had known where they were going.
Beinn a' Chroin is one of a number of rocky Munros that lie just south of the village of Crainlarich, with the West Highland Way passing below.
It can be climbed from the glen on its own, or paired with the higher An Caisteal.
Others peaks over 3,000 ft in the area include Beinn Tulaichean, Cruach Ardrain, Beinn Chabhair, Ben More and Stob Binnein.