For a turbojet aircraft, how is maximum range performance achieved as weight decreases?

For a turbojet aircraft, maximum range performance is achieved as weight decreases primarily by decreasing speed or increasing altitude. This is because, as the aircraft becomes lighter, it requires less thrust to maintain flight, which allows the aircraft to operate more efficiently.

When the altitude is increased, the aircraft encounters thinner air, which reduces drag. This enables the turbojet to operate more efficiently and consume less fuel over the same distance, leading to improved range. Conversely, decreasing speed lowers the drag as well, especially at suboptimal speeds where the aircraft is not operating at its most efficient cruising speed. Therefore, either strategy contributes to maximizing range by optimizing fuel consumption relative to distance traveled.

The other choices imply actions that either increase drag or do not take advantage of the advantages conferred by altitude and speed adjustments. Thus, the correct approach to extending the maximum range with decreasing weight is through either decreasing speed or increasing altitude.