While there is work to be done to help the Delta-Virgin Atlantic partnership and Delta’s investment pay off, the leaders of both carriers are expressing confidence in the benefits of the deal—and noting some near-immediate payoffs.

Together, the carriers will operate 31 peak-day flights between the U.K. and North America, including 23 from Heathrow. The latter will include seven daily roundtrip flights between Heathrow and New York Kennedy Airport, where Delta operates an international hub, and two between Heathrow and Newark Liberty International Airport.

Delta currently operates only three daily flights between New York and London (all to Heathrow) because of the slot constraints at Heathrow, and only nine in total to Heathrow from any point in the U.S. Delta says the combined operations will give the carriers about a quarter of the Heathrow flights.

New York is a critical component of Delta’s growth strategy—with big service build-ups and investments at Kennedy and LaGuardia Airport—but the dearth of Heathrow access remained a big hole in its drive to become the No. 1 carrier in the New York area and continue to increase its share of corporate traffic. The Atlanta-based carrier is getting Virgin Atlantic and its slots at what could be considered a bargain price, with Singapore having paid about $966 million when it acquired its 49% share 12 years ago. J.P. Morgan analyst Jamie Baker recently estimated the value of Virgin’s long-haul slot portfolio at Heathrow at $660 million to $880 million.

Delta and Virgin Atlantic also hope to begin frequent flyer reciprocity and code-sharing as soon as possible, and Anderson says Delta already has the corporate deal structure in place to incorporate Virgin Atlantic into those contracts “almost instantaneously”—even, perhaps, with the restricted cooperation between the carriers before an immunized joint venture is approved.