Originally Posted by
Wasabi Tofu
For this particular case, ExpertFlyer shows AA8432/8413 for simple NRT-SIN-NRT seach specifing AA.
A simple NRT-CGK-NRT search (AA only) returns AA8499/AA8497,AA8498
So, probably, you can book without a connecting AA flight.
Is that reliable? A quick check and I couldn't see an AA marketed flight for NRT-SIN-NRT on ITA (searching for a 2-9 day trip starting in April).
Also: HKG-SIN-HKG showed up as AA marketed in expert flyer but there was consistently no D class availability.