Engine makers are accelerating production efforts amid a rise in aircraft purchasing by carriers seeking more efficient models. At a time when fuel represents the largest share of airline operating costs, improvements in under-wing technology have helped jets operate more economically, said Richard Aboulafia, an analyst at Fairfax, Virginia-based Teal Group. "It becomes essential to replace older, less-efficient jets with newer ones. They pay for themselves," he said."Every decade we get about 10 or 12 percent better. The meaning of that double-digit improvement is so much greater because of the high cost of fuel."

The venture had the good fortune to propose a brand-new engine concept in the mid-1970s, around the time that the United States Air Force was considering a revamp of its entire fleet of aerial refueling tankers. At about the same time, Boeing and Airbus were preparing to develop the generation of short-range single-aisle jets that have become the workhorses of the air travel industry. “From an industry standpoint, this was a winning lottery ticket,” said Richard L. Aboulafia, an aerospace analyst with the Teal Group in Fairfax, Virginia.

Virginia-based Teal Group analyst Joel Johnson said the move could help American firms to put themselves in a position to benefit if a broader softening of sanctions is agreed. "It allows some US companies to get a foot in the door and restore relations that they have not had for over 20 years," Johnson said.