The Prime Minister has met aircraft workers at Bombardier's Belfast factory in the wake of the company's trade battle victory in the United States.
Theresa May toured the plant floor where the wings of the Canadian manufacturer's C Series jets are built ahead of her visit to Stormont to meet Northern Ireland's political leaders.
Bombardier's bitter trade dispute with Boeing had threatened jobs at the Belfast plant after the United States trade authorities sided with the US company and proposed a 292% tariff on the import of its rival's planes into the country.
There was a huge sigh of relief in Belfast when that decision was overturned by the US International Trade Commission (ITC) in Washington DC last month.
One thousand of the 4,000 strong workforce at the Belfast factory work on the C Series production line.
Mrs May chatted with some of them on Monday morning as she was shown the assembled wings at close quarters.
She also met with senior company executives.
The ITC ruled that Boeing did not suffer injury from an order of C Series jets placed by Atlanta-based Delta Airlines.
The Prime Minister directly lobbied President Donald Trump on a number of occasions during the trade row.
Boeing had claimed state aid offered to Bombardier by government administrations in the UK and Canada breached international trade rules and enabled Bombardier to sell its jets in the US below cost price.
The US Commerce Department agreed and suggested the massive import tariff on Bombardier.
The ITC's role was to determine whether the aircraft manufacture industry in America was damaged by the imports.
Bombardier had argued the proposed 292% tariff threat ignored long-standing business practices in the aerospace industry, including launch pricing and the financing of multi-billion-dollar aircraft programmes.
But Boeing alleged its business was damaged because Bombardier received inappropriate government subsidies, dumping the C Series in the US through the cut-price 2016 Delta sale of 75 jets.
The ITC rejected Boeing's claim and ruled that the import of C Series jets did not injure US industry.