A valued crew member of any airplane, a flight engineer is responsible for ensuring that all components of the plane are in proper working order. It is their duty to make any of the repairs if a mechanical issue does arise. Flight engineers are also used to interpret complicated flight-related gauges and instruments, and to help pilots with navigation. Unfortunately, several of these duties have been diminished due to the emergence of automated computer programs, capable of performing several of the same duties at a much lower cost. Regardless, flight engineers are still widely used by the military and by companies with larger aircraft. This is because military aircraft use the most recent technology, operate under different systems than commercial airlines, and are at higher risk of attack or mechanical problems. Certain countries also have laws requiring all three and four engine airplanes to carry a licensed flight engineer.