Have to agree with both Motto and Lang: three
excellent books mentioned there that I can't rate highly enough.
Add to them Harry Benson's 'Scram' about helicopter ops in the Falklands: gripping stuff avoiding Argentine Pucara G/A aircraft and other difficulties.
Not purely helicopter, but Robbins 'The Ravens' about light air/nap of the earth ops over Laos is another gripping narrative.
Dave, no Iroquois at the Cleveland convention, but there was an air component in the form of a nicely restored and airworthy B-25 and a couple of other lighter aircraft, plus some big un-restored lumps from the freighter version of the B-29. Combined with an original LCVP 'Higgins boat', it made for a more diverse show that usual. The Higgins was of particular interest: not much timber between you and the incoming 7.92-mm at 1100 rounds per minute. No wonder so many didn't even get onto the beach on June 6.
Mike