Do Airline Deals Favor Boeing or Airbus?

Looking ahead, Aboulafia says Boeing would benefit from the merger because Delta is committed to Boeing. It recently took delivery of a Boeing 777-200LR, its first new aircraft in six years, and plans on getting more jets. "There is no question that now, they will have a management heavily inclined toward Boeing," Aboulafia says.

However, aviation consultant Scott Hamilton contends that, "despite the conventional wisdom, I am not willing to concede that the new Delta is a lock for Boeing." Hamilton notes that Northwest grew its Airbus fleet during Anderson's tenure and that the Delta CEO has indicated the combined carrier will continue to have a balanced fleet.

Currently, Northwest flies about 130 Airbus narrowbodies and is the world's largest operator of the A330, with nearly three dozen of them. It also has 18 Boeing 787s on order, with options for 50 more.

As for a United and US Airways combination, Aboulafia says Airbus dodged a bullet when merger talks between United and Continental(CAL Quote) broke off, because Continental has an all-Boeing fleet and its management would likely have run the company.

By contrast, "the management of US Airways is the most pro-Airbus management of all U.S. airlines, and United has some Airbuses too," he says. "So Airbus looks to be a lot better off."

The carrier's widebody order, reaffirmed at the Paris Air Show last June, is for 22 A350XWBs, starting in 2014. US Airways is the only U.S. carrier to have selected the A350 instead of the 787 as its widebody plane of the future.

The order also includes 10 A330s, with deliveries starting in 2009, and 60 A320s, arriving between 2010 and 2013. Most will replace Boeing aircraft. Within a few years, Boeing's representation in US Airways' fleet would be limited to 20 of its 757s. At United, about two-thirds of the 460 mainline aircraft are Boeing.