I know I've suggested it before, but to repeat myself, 'We Were Soldiers Once... and Young", where Ed Freeman's actions that day are described in detail, is an excellent read.
The Huey main rotor has a 48' diameter. At one stage during his rescues that day, there were NVA within Freeman's rotor disc shooting up at him as he came to the hover! Anyone who's flown a dustoff in a Huey - in far, far less exciting circumstances that that - will understand that what he did that day was extraordinary, both in the flying skill displayed and in sheer bravery.