Modern aircraft have not removed the human from the system. They have changed the human's role within it.
Automation can reduce manual workload while increasing the importance of monitoring, mode awareness, shared mental models and timely intervention. The CRM relationship is no longer only pilot-to-pilot; it also includes how both pilots understand and manage the automated system.
From pilot ↔ pilot to pilot ↔ pilot ↔ automation
Modern CRM therefore includes parallel questions: What is the aircraft doing? Why is it doing it? What will it do next? Does the other pilot have the same understanding of the automation state? When should the crew intervene or reduce the level of automation?
Automation does not eliminate Human Factors. It relocates them — toward monitoring, understanding, decision-making and intervention.
What does “Level 4 automation” mean?
There is no single universal aviation definition. Different automation taxonomies use the same level number differently. The safer professional approach is to define the automation framework being used rather than assuming “Level 4” has one accepted cockpit meaning.
The CRM consequence
As automation capability increases, crews need a shared mental model of aircraft state, automation state, intended flight path, system limitations and intervention strategy. Communication, situation awareness, decision making and workload management therefore remain central competencies.
The question is increasingly not whether the machine can perform the task, but whether the human understands what the machine is doing, why it is doing it, and when to intervene.