Tensions between Washington and Ottawa have flared again after US President Donald Trump threatened sweeping trade penalties on Canadian-made aircraft, escalating a long-running dispute over aviation certification standards. According to Trump, Canada’s certification process has effectively shut Gulfstream out of the Canadian market. US Warns of De-Certification for Bombardier AircraftIn response, Trump announced that the US would retaliate by decertifying Bombardier aircraft, including its high-profile Global Express jets, unless Canada reverses its position. “We are hereby decertifying their Bombardier Global Expresses, and all aircraft made in Canada,” Trump said, adding that certification would remain suspended until Gulfstream receives full approval. He warned that failure to certify Gulfstream jets would trigger a 50 per cent tariff on any and all Canadian aircraft entering the United States.