The first test flight of a jet partly built at Bombardier's Belfast plant is set to take place later this week.
The Canadian aerospace giant will take its long-awaited CS300 jets - of which the wings are made in Belfast - to the skies at some stage from Thursday onwards.
The aircraft is expected to perform a series of handling and system calibration tests, at a wide range of altitudes and speeds during the flight.
Bombardier Aerospace is the world's largest manufacturer of both planes and trains, and employs around 6,000 people in Northern Ireland.
Earlier this month, the firm announced it was axing up to 130 agency workers. Last year 90 staff and 300 contractors lost their jobs in Northern Ireland.
Currently Bombardier has orders and commitments for the 563 CSeries aircraft which is expected to enter service at the end of the year.
Bombardier's Rob Dewar said: "This is an exciting time. The first four CS100 Flight Test Vehicles (FTVs) have flown more than 1,000 hours and initial tests for the CS300 FTVs are looking great."