What occurs when air density decreases?

When air density decreases, it affects the performance characteristics of an aircraft, especially in terms of its landing speed and engine power output. Lower air density, commonly encountered at higher altitudes or in warmer temperatures, means that each unit of air has fewer molecules. This reduction in air density leads to a decrease in lift generated by the wings because lift is directly proportional to air density. As a result, to achieve the same amount of lift during landing, an aircraft needs to have a higher true airspeed, which translates to a faster landing speed.

Additionally, the decrease in air density also influences engine performance. Engines produce less power in lower-density air, primarily due to a reduction in the amount of oxygen available for combustion. Therefore, when air density decreases, engine output tends to decrease as well.

Thus, in this scenario, the correct implication is that landing speed increases (because more speed is required to generate adequate lift), and engine power typically decreases due to the lower density of air available for combustion.