Jargon 
I found sources defining the three terms tagged as jargon if someone wants to edit them in.
".. a thing called the jitterbug. Jitterbugging around, trying to surround enemy units with helicopters,..."

"...squad sized elements. These elements had fixed areas of operations comparable to the squares of a checkerboard, and once in these areas of operations they moved continuously from one terrain feature to another in order to interdict the enemy."
more detail

"..."Eagle Flight" choppers were loaded with Vietnamese airborne troops who were dropped in to support ground forces at the first sign of enemy contact."

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