I. Halt. The main events of the incident, including the supposed landing or landings, took place in the forest, which starts at the east end of the base runway or about 0.3 miles (0.5 km) to the east of the East Gate of RAF Woodbridge, from where security guards first noticed mysterious lights appearing to descend into the forest. The forest extends east about one mile (1.6 km) beyond East Gate, ending at a farmer's field at Capel Green, where additional events allegedly took place. Orfordness Lighthouse, which sceptics identify as the flashing light seen off to the coast by the airmen, is along the same line of sight about further east of the forest's edge. At that time it was one of the brightest lighthouses in the UK. Primary and secondary sources The Halt memo The first piece of primary evidence to be made available to the public was a memorandum written by the deputy base commander, Lieutenant Colonel Charles I. Halt, to the Ministry of Defence (MoD). Known as the "Halt memo", this was made publicly available in the United States under the U.S. Freedom of Information Act in 1983. The memorandum, was dated "13 Jan 1981" under the title "Unexplained Lights". The two-week delay between the incident and the report might account for errors in the dates and times given. The memo was not classified in any way. David Clarke, a consultant to the National Archives, has investigated the background of this memo and the reaction to it at the MoD. His interviews with the personnel involved confirmed the cursory nature of the investigation made by the MoD, and failed to find any evidence for any other reports on the incident made by the USAF or UK apart from the Halt memo. Halt has since gone on record as saying he believes that he witnessed an extraterrestrial event that was then covered up. The Halt Tape In 1984, a copy of what became known as the "Halt Tape" was released to UFO researchers by Colonel Sam Morgan, who had by then succeeded Ted Conrad as Halt's superior. This tape chronicles Halt's investigation in the forest in real time, including taking radiation readings, the sighting of the flashing light between trees, and the starlike objects that hovered and twinkled. The tape has been transcribed by researcher Ian Ridpath, who includes a link to an audio download and also