Bombardier has been dealt a body blow after a US airline placed a major order with a rival company.
United Airlines has said it will buy 40 of the 737-700 planes from Boeing, in a deal worth $3.2bn (£2.3bn).
It's another missed deal for Canadian-owned Bombardier - which employs 5,500 people in Northern Ireland - as it struggles to meet target orders for its CSeries planes.
It now has orders for 243 jets.
But there could still be hope for Bombardier, as another US firm, Delta Airlines, is weighing up its options over purchasing the aircraft.
Bombardier's Belfast workforce produces a range of planes for the firm, including wings and fuselage for the CSeries jets.
Meanwhile, some of the world's biggest aerospace firms have visited Northern Ireland.
Firms taking part in the visit, aimed at furthering supply chain relationships, included Airbus, Cobham - which is the fifth largest defence firm in the UK - and engineering firm Meggitt.
Philip McBride, chairman of aviation industry body ADS, said: "We have a very strong, high quality aerospace supply base and we are very keen to develop these important relationships in a way which is beneficial to the sector and to industry in Northern Ireland."