What is the Selected Altitude off scale?

The concept of selected altitude off scale refers to the altitude setting that is surpassing the maximum limit of what can be displayed or set on the aircraft's altimeter or flight management system. In the context of the A320, the selected altitude options typically provide a range that pilots can set based on air traffic control instructions or flight procedures.

In this case, 3000 feet is the correct answer because it represents a commonly used altitude setting that is often encountered during operations. Typical air traffic control altitudes and flight levels are structured around thousands of feet, and 3000 feet is a standard altitude used by pilots for initial climbs or approach phases of flight.

Using altitudes such as 1800 feet or 3035 feet can be less standard in operational contexts, especially considering that 1800 feet is often a minimum safe altitude in certain situations but not a typical selected altitude via systems, and 3035 feet would be an off-scale setting which is not commonly addressed in basic altitude selection protocols. By understanding these operational preferences and standards, pilots are better equipped to manage their aircraft altitude settings in compliance with air traffic regulations and to maintain aircraft safety during flight.