Bombardier Aerospace in Belfast has secured a multi-billion pound order for up to 275 aircraft.
While the deal will not save 1,200 jobs being cut in Belfast because of the downturn in the airline industry, it should go a long way to secure work for those remaining.
Bombardier headquarters in Toronto announced it had signed a contract with US Airways with a potential value of seven billion US dollars (€6 billion).
The contract involves 85 firm orders for the Bombardier CRJ200 50-seat and CRJ700 75-seat regional jets worth some $2.2 billion, the company announced.
A further 100 options on a mix of the aircraft and 90 reconfirmed orders are involved in the deal.
Mr Michael Ryan, vice-president and general manager of Bombardier in Belfast, said the company welcomed the orders.
The Belfast plant is responsible for the detailed design and manufacture of large parts of the aircraft including forward and central fuselages, engine nacelles, stabilisers and wing components.
Mr Ryan said that despite the welcome news there would be no additional jobs created and planned job cuts would continue.
However he added: "It will help sustain current production rates, making the remaining jobs more secure, provided we can improve our competitiveness."
Around 3,200 of the current workforce in east Belfast of 5,750 are involved in the CRJ200 and CRJ700 programmes.
Due to the downturn in the worldwide airline industry and a drop off in orders, Bombardier made 380 workers redundant before Easter with another 100 due to go this week.
The balance of some 700 jobs is expected to go later in the year.
Despite the jobs losses Bombardier is still Northern Ireland's largest manufacturing employer and responsible for much more employment in local sub-contractors.
PA