HNL-LHR won't work as it's backtracking to NA, but you'd need to call AA, BA, or whomever to verify. You could also try the OW booking tool, but it's so buggy I wouldn't trust what it says either.
You would not be able to get A on HNL-LHR anyway, because only D is available on that flight, EVEN IF you are allowed to book this flight it is booked as two segments according to EF (although OW booking tool shows it as 1 segment which is a plus in your favor) and would be booked into D class at best.
HNL-LHR AA 108 (shows as 2 flights in EF - No A class)
AA 108 HNL-LAX
J7 R0 D7 I2 Y7 B0 H7 K7 M7 L7 G7 V7 S7 N7 Q7 O7
AA 108 LAX-LHR
J7 R0 D7 I2 Y7 B0 H7 K7 M7 L7 G7 V7 S7 N7 Q7 O7
LAX-LHR AA 108 (LAX-LHR booked separately)
F7 A6 J7 R7 D7 I7 Y7 B0 H7 K7 M7 L7 G7 V7 S7 N7 Q7 O7
I agree while mileage monkey is a nice planning tool, it is not an authority on xONEn rules by any stretch of the imagination.
FWIW, I'm doing my first DONE4 this fall into next year because i'm including Hawaii in the itinerary. Doing DFW-HNL-SYD and then to Asia with BA from PVG to LHR and upgrading to F using Avios for that flight and the LHR-IAD TATL (which is a little overkill with no overnight) flight. I usually do AONEn or ACIRnn and love CX and QF F, but with Hawaii I didn't need the TPAC and no A to/from Hawaii, so went with DONEn.
Last edited by aaupgrade; Jul 15, 2017 at 7:13 am