Slots and gates my boy!
While, TWA isn't the largest carrier in the country, it once was, and remnants of that error are still held by TWA, some good (slots, gates at congested airports) some bad (antiquated work rules, old planes etc...).
TWA owns 17 gates at JFK, 7 at SFO, 4 at LGA, 4 at PHL, 2 at DCA, and 2 at BOS.
TWA holds 84 slots at JFK, 51 slots at LGA, and 33 at DCA.
Also, TW has plenty of mech capacity with a large overhaul base in LA that has room for 3 narrowbody planes and 3 widebody planes.