Late last month, the US Commerce Department slapped import duties of 220% on Bombardier’s new C Series jetliner, which cost at least $6-billion to develop. The protection, which followed a compliant by Boeing, was justified on the basis of Bombardier receiving improper subsidies. Bloomberg reports that the preliminary determination threatens to upend Bombardier’s planned deliveries next year to Delta Air Lines, which ordered at least 75 jets with a list value of more than $5-billion.