The Great North Air Ambulance Service (GNAAS) was called to an injured cyclist taking part in the Fred Whitton Challenge on Sunday.
The man suffered severe leg injuries and minor head and facial injuries.
The GNAAS aircraft landed at the Slate Mine before aircrew were transported to the patient by event medics. The doctor-led trauma team assessed and treated the man, in his 40s, before he was flown to hospital in Preston within 20 minutes. He arrived in a stable condition.
GNAAS was called to the incident at 10.05am.