Are there even 42 737 capable airports in Aus ?
Didn't take too long to think of 42 off the top of my head, excluding mining charter airports. Not that all would suitable for leisure LCC traffic!
NSW (6): SYD, ABX, TMW, NTL, CFS, BNK
Qld (15 ): WTB, OOL, MCY, HVB, BDB(?) GLT, ROK, MKY, HTI, PPP, TSV, CNS, ISA, GOV, LRE(?)
NT (4): DRW, ASP, AYQ, KTR
WA(9): KNX, BME, LEA, PHE, GET, KTA, KGI, BQB, ZNE(?)
SA(1): ADL
VIC(3); MEL, AVV, MQL
TAS(2): HBA, LST
ACT(1): CBR
Oth(1): XCH