I'd love to see the route timing on those Portland flights. I wonder if what it actually is is a parking move; HVN is basically full to bursting and has no spare stands at which to park an additional 737 at. It has capacity for what, 5 airliners to be parked there? PWM is roughly a 35-50 minute flight away, which is close enough for an aircraft to overnight there and make it back to HVN quickly enough to make a
6th morning flight out of HVN possible, without waiting for a plane to arrive from say, RDU - and is likely just far enough away to be a plausible revenue flight. That also positions it well for connections, otherwise they might be better suited just repositioning the plane to/from BDL, but ULCC means they are hoping someone will pay them to fly.
(Not to say major airlines don't - it's one of the reasons planes overnight at outstations for most of the legacy carriers - not enough gates at their hubs.)
New Haven will be getting a much needed new 81,000 sf six gate terminal in the future along with its runway being lengthened to 6650'. Interesting to see that Avelo is commencing service out of Portland during the same time that the 2 gate expansion becomes operational just before Memorial Day. They will probably be forced to share a ticket counter with another less frequent airline because all of the available space is being utilized.
Well, that helps explain how Breeze is planning on squeezing in down there - they start flights from HVN to RSW (Ft Myers) literally tomorrow, adding Orlando, West Palm Beach, and Vero Beach before the end of the week. It's interesting that Avelo and Breeze are getting into each other's bases - Avelo adding service in Breeze's BDL base and vice versa in HVN.
That said, HVN has to be the fastest growing airport in the country right now, and that terminal must be overcrowded to bursting. It managed to serve through WW2 and the jet age (having been built in 1931) without running into capacity problems. I understand they're already relying on trailers to create enough indoor space - if Avelo and Breeze prove HVN to be a viable market in addition to BDL? Maybe that new terminal will need another expansion.