The police helicopter was called to Horsham this morning after reports were received of a gunman inside a house.
Police cordoned off Hazelhurst Crescent after receiving a report a man was alone in a property with a gun at about 9am.
Police said officers talked a man out of the building and he was arrested on suspicion of making threats to kill.
The man, who is in his early thirties, is currently in custody for further enquiries.
No-one was injured, no shots were fired and no gun has yet been found, officers added.
Residents in Wickhurst Green and Broadbridge Heath raised concerns after the police helicopter was seen hovering near Shelley Primary School earlier this morning.
Police said the incident had no connection with the area and there was no threat to local people or schools.