In a blog post published in September, Allen also warned that he would not have an obvious means of returning to the outside world — which he said was “somewhat worrying, especially at my advanced age.”
He explained that the aim of his trip to Papua New Guinea was to create a brief record of how the tribe lives and possibly track down some of the people he met in the 1980s.
The explorer said he was unsure how members of the Yaifo tribe would react to him or if he would even make it to where he believes they are located due to the “rather treacherous terrain.”
“Last time, the Yaifo 'greeted' me with a terrifying show of strength, an energetic dance featuring their bows and arrows,” he wrote. “On this occasion who knows if the Yaifo will do the same, or run off, or be wearing jeans and T-shirts.”
Saphora Smith is a London-based reporter for NBC News Digital.