JFK wanted out of Vietnam. LBJ was deep into Bell helicopter and other corporations that would benefit from the war. LBJ had JFK whacked, possibly RFK too although the mafia wanted him out of the way also.
LBJ had alreafdy done his part by steering the three finalists for the DoD Light Observation Helicoter competition to the Bell YHO-4, Fairchild-Hiller YOH-5A, and Hughes OH-6 - all Texan firms.
The Question becomes who benefited from the final selection of the the Hughes OH-6?
And Consider this, nobody knows for certain where Howard Hughes was that particular day
That’s my take.