The Boston Globe reported Logan International Airport spokesman Phil Orlandella said Massachusetts State Police, aided by search dogs, and FBI agents found no evidence of explosives in the aircraft and passenger baggage.
Virgin Atlantic Flight 11, which left London's Heathrow Airport with 200 passengers and 16 crew members on board, landed in Boston about 6 p.m.
State Police Trooper Thomas Murphy said the suspicious note was found in an aircraft bathroom. He said while the note's implied threat of a bomb did not appear credible, authorities were investigating the incident.
Boston's WCVB-TV reported the note was discovered by a flight attendant and that it mentioned the date Nov. 11.