Sacha Dench had been dubbed the “human swan” as she attempted a 3,000-mile motorized paraglider trip to mark the United Nations COP26 climate change conference on October 31.
Dan Burton, a member of his support staff, was killed in the incident on Saturday afternoon near Loch Na Gainmhich.
Ms Dench is currently at Aberdeen Royal Infirmary in serious but not life-threatening condition.
In a statement, Conservation Sans Frontières administrators said: “We are very sorry to have to confirm that Dan Burton, the support paramotor, died as a result of the crash.
“Sacha Dench is seriously injured and is treated in hospital. His injuries are serious but do not endanger his life.
“Both very experienced paramotors, our hearts go out to the family of Dan Burton, to whom we offer our deepest condolences.
“The incident has been followed up by police and medics and investigations are underway to establish the details of the accident. “
The statement added that the families of those involved had been informed and the Round Britain Climate Challenge would now be suspended.