Non-excusable delays include anything that falls outside this catalog, but are rare, experts say. Only the grounding of the Boeing 737 MAX over design defects was treated as a non-excusable delay on a significant scale, resulting in hefty compensation payments from Boeing, industry sources said. With last year's deliveries below target and doubts rising over 2023, planemakers are once again invoking the "excusable delay" clause, buyers said. Airbus and Boeing declined comment on contractual matters.