Trans Australia Airlines TAA trialled JATO on DC3 aircraft in the hot and high operating conditions of Papua New Guinea in the 1960's.
Not entirely sure as to the accuracy of this but rumour has it that gathered dignitaries were present to witness the inaugural JATO takeoff of a fully loaded PNG DC3.
However the system failed to ignite and the lumbering aircraft disappeared off the end of the runway and down a valley only to emerge miles away at runway height, to much official clearing of throats and embarrassment.
Don't think it was ever used operationally much after that.
Photos courtesy TAA museum