When the first Flight Management Systems (FMS) were being introduced many years ago, a common phrase heard in the cockpit was, “What’s it doing now?” Up to that point it was the pilot who analyzed the raw data and made all the decisions about when to change over to a new fix or a new navigation source. While it could sometimes be a challenge to put together all the available information to figure out where you were or where you were supposed to be going, it was up to you. In a crew situation the pilot not flying might occasionally wonder “What’s he doing now?” about the pilot flying the airplane, but he could then clarify the situation by asking the pilot.
The introduction of the FMS was like adding a person to the cockpit. Once programmed by the pilot, the FMS would make decisions such as when to change to the next fix all by itself. Unlike a person, you couldn’t ask it questions about what it was doing or why it was doing it. This led many pilots to feel like there was now another “brain” in the cockpit-a somewhat mysterious, even malicious creature that had taken over their airplane as they sat there wondering “What’s it doing now?”