"Lockheed Martin will lead with $52.5 billion in total funding, based on leadership in C4I (Command, Control, Communications, Computers and Intelligence), and dominant positions in electro-optics (EO) due to airborne fighter and attack helicopter targeting system markets, and in sonar due to A-RCI (Acoustic-Rapid COTS Insertion)," said Teal Group's senior electronics analyst and author of the new manufacturer market shares overview, Dr. David Rockwell.

"They will also hold a solid third in the radar market based on another dominant program, the naval AN/SPY-1 Aegis system," said Rockwell "Lockheed Martin has strengthened its future in many markets where it had previously been a minor player, only recently rising above Northrop Grumman and Raytheon in the overall electronics market future."

"I would just guess it's for radar signature testing," Richard Aboulafia, an analyst with the Teal Group, said when asked what the F-117 could be doing. "It could conceivably be testing aerodynamics, also. It was one of the earlier generations of planes that shouldn't have been flying but did, thanks to the magic of fly by wire and computers. It could also be fatigue testing for materials that were used on the plane, to see how well those are holding up over time."

Another option is they are test beds of a different kind — retrofitted into unmanned systems, perhaps to check on the capability of optionally-manned systems for stealth aircraft. And of course it's possible they are being kept warm in case of military need, but it's hard to see what gap they would be fitting specifically in the military network.

All of which is to say, as Aboulafia put it, the planes could be used to test "any number of things."

Richard Aboulafia, an analyst with the Teal Group, agreed that the engines make sense from both a fiscal and operational viewpoint. "You'd cut fuel and maintenance in half just for starters, and you can lift more and do it faster," Aboulafia said. "It's better across the board and cheaper across the board. There are no drawbacks."

Mitsubishi's problem is Embraer's headstart of over 1,000 aircraft orders, along with an established reputation for financing, reliability and after-sales service, said Richard Aboulafia, vice president of analysis at consultancy Teal Group.

After the MRJ came into the picture, Embraer said it would upgrade its E-Jets with the same fuel efficient Pratt & Whitney engines under the name E2. These will be delivered from 2018 only a year after the delayed MRJ.

"The E-Jet E2 will produce economics every bit as competitive as the MRJ, despite the lack of clean-sheet design," said Morris.

Mitsubishi has a better chance of displacing Bombardier, which has bet big on developing its CSeries to break into the market for 150-seat aircraft at the expense of its CRJ regional jets, said Aboulafia.

"The 350 is a very serious threat and it's very well executed on," said Richard Aboulafia, aerospace analyst for the Teal Group, an analyst firm outside Washington, D.C. "Boeing was dragging its heels on the 777X and the 787-10, the A350 is a far bigger success than it would have had Boeing been quicker."

He added that Boeing's strained relations with its two largest unions is a potential liability, as the company develops the design and manufacture of the 777X.

"Bad workforce relations are a risk," he said. "It doesn't guarantee that you're not going to execute as well as Airbus did on the A350, but it adds risk. Airbus has better labor relations."