Originally Posted by
ORDnHKG
Incorrect, no matter if you are in a *A flight or not, RCC or PC one day pass only valid on RCC or PC (now united club), no other *A lounges accepted.
And now you cannot even visit multiple RCCs/PCs in a day on one $50 pass unlike the old days with CO day passes.
There is only one very unreasonable way to get into the NH lounge flying AA.

Buy a *A paid lounge membership and a refundable *A flight or a refundable *A C/F ticket and you'll be good to go!