Most older planes used the 3 crew system to work the plane where you had the Pilot, the co-pilot and the Flight engineer.

The flight engineer was responsible for checking all plane systems and making sure nothing went wrong and if it did find a solution for this.

Nowadays the function of the flight engineer have been replaced by processors and alarms.

while you may get answers here, it may be worthwhile x-posting to a specialist sub like /r/aviation