1947.07.30
On 30 July the FBI issued instructions to all its agents to cooperate fully with the military – an arrangement which was to last barely a month.
(The Complete Book of UFOs, Hough and Randles)
FLYING DISCS – The Bureau, at the request of the Army Air Forces Intelligence, has agreed to cooperate in the investigation of flying discs… The Army Air Forces Intelligence has also indicated some concern that the reported sightings might have been made by subversive individuals for the purpose of creating mass hysteria.
You should investigate each instance which is brought to your attention of a sighting of a flying disc in order to ascertain whether or not it is a bona fide sighting, an imaginary one, or a prank. You should also bear in mind that individuals might report seeing flying discs for various reasons. It is conceivable that an individual might be desirous of seeking personal publicity, causing hysteria, or playing a prank.
The Bureau should be notified immediately by teletype of all reported sightings and the results of your enquiries. In instances where the report appears to have merit, the teletype should be followed by a letter to the Bureau containing in detail the results of your inquiries. The Army Air Forces have assured the Bureau complete cooperation in the matters and in any instances where they fail to make information available to you or make the recovered discs available for your examination, it should promptly be brought to the attention of the Bureau.
Any information you develop in connection with these discs should be promptly brought to the attention of the Army through your usual liaison channels.