But I think it's worth noting to the (mostly software oriented) HN crowd - aerospace projects have massive manufacturing cycle times. Some things literally take years to manufacture for the proof-of-concept stage, let alone production. You can't NOT be incredibly schedule-oriented in this environment. This can cause some perverse incentives for management (which must be mitigated), but there are always going to be somewhat risky last-minute changes that could seem ill-advised in hindsight if you want to deliver something.