Airbus' single-aisle A321neo has snapped up billions of dollars of orders in a recently booming segment of the market, as the largest MAX variants struggled to block it.
"I'm confident that over a longer period of time, we'll get back to where we need to get to and I'm confident in the product line," Calhoun said in April as Boeing won new MAX orders.
"2020 was one of the most challenging years in aviation history. For Spirit, the 737 MAX grounding and the COVID-19 pandemic created a dual-crisis," Spirit Chief Executive Officer Tom Gentile said.
Spirit's total deliveries of shipsets, or complete sets of parts, fell 48.9% to 231 units in the fourth quarter. Boeing 737 MAX deliveries fell to 19 shipsets from 153 a year ago.
Investigators said a main cause of both crashes was a faulty flight handling system known as the Maneuvering Characteristics Augmentation System, or MCAS.