Once past flaps 25 all of the flap movement is down and not aft. So flpas 30 and flaps 40 really add a ton of drag and little lift and do require alot of power at those flaps settings. The flaps on the 727 are huge and the triple slotting creates a huge amount of lift. Most planes are restricted to flaps 25 or 30 landing for nopise abatment. At flaps 30 or 40 your creating a hell of alot of drag and alot of power resulting in alot of engine noise. The simulation is accurate inthat respect. Try landing at flaps 25 and add 10 knots to VAPP and 5 to VREF.