The Journal says the cause for delay involves a temperature-regulating part called a heat exchanger. Boeing had been getting them from a supplier in Russia, but when that country launched a full-scale invasion of Ukraine and trade restrictions were put in place against Russian goods, Boeing started getting them from British and American suppliers. But they haven’t been able to make as many. The heat exchanger is one of “a few key parts” that Boeing has told staff is behind a 787 slowdown in a memo last week. Combined, the 787 and the also-delayed 737 Max make up 98% of the planemaker’s current order backlog.

Hopefully it gets worse.