Boeing on Wednesday disclosed a heavy first-quarter loss as it wrote off $1.2 billion related to two defense-side fixed-price aircraft projects and the impact of the war in Ukraine. The company also announced it will push out delivery of the first giant 777X jet at least a year to 2025 — a delay that it estimates will incur a further $1.5 billion in abnormal production costs in future quarters. Boeing said it will pause 777X production in Everett, Washington through the end of next year to avoid building up more inventory. It has already built and rolled out four flight test models and 20 prod…