The CIA knew where the plane was, but shouldn't have, so they used a medium to fabricate a 'guess'.
So instead of investigating them he just decided to believe any bullshit they told him no matter how absurd. Nice one Jimmy.
In 1998, documents were discovered which detailed an alleged plot, named Operation Celeste, to assassinate Hammarskjöld. The alleged plot was backed by the CIA, MI6 and a Belgian mining interest and the assassination was to be carried out by the South African Institute for Maritime Research, a South African paramilitary organisation.
One of the documents stated that CIA director Allen Dulles agreed that "Dag is becoming troublesome ... and should be removed" and pledged local CIA support for the alleged plot. The information was contained in a file which the South African National Intelligence Agency turned over to the South African Truth and Reconciliation Commission in relation to the 1993 assassination of Chris Hani, leader of the South African Communist Party. The authenticity of the documents could not be substantiated because they were copies instead of originals. More documents related to the alleged plot were discovered by the South African government in 2016.
South African Institute for Maritime Research, a South African paramilitary organisation.
What a name for a paramilitary organization
South African Institute for Maritime Research (SAIMR or SAIMAR) is the name of a paramilitary organization that is believed to have performed clandestine operations to support white supremacy in Africa.
SAIMR first became publicly known during sessions of the South African Truth and Reconciliation Committee (TRC) in August 1998. A year before the second elections after the end of Apartheid, documents emerged implying SAIMR had a role in a plot to kill Dag Hammarskjöld, the UN Secretary-General, in 1961.
Letters with SAIMR’s official letterhead were found during the TRC hearings. The letters suggested that MI6 and the CIA had agreed that Hammarskjöld should be removed, a suggestion both organizations denied. Testimony from an alleged ex-SAIMR operative that SAIMR deliberately spread HIV among black people in Africa.
We had our best shot at disclosure with Trump and he's not going to do it.
I think "the CIA/Pentagon encourage and feed UFO kooks false information to protect top secret aircraft programs" is the kind of thing no President is going to announce publicly