In a flight with a weight of 3,400 lb at 4,000 ft pressure altitude and calm winds, what is the expected takeoff distance over a 50-foot obstacle at a temperature of 90°F?

To determine the expected takeoff distance over a 50-foot obstacle, one must consider several key factors, including weight, altitude, temperature, and the performance charts specific to the aircraft being examined.

In this scenario, the weight of the aircraft is 3,400 lb, which is moderate and will not significantly hinder takeoff performance. The pressure altitude is 4,000 ft, which, combined with a high temperature of 90°F, can adversely affect engine performance and aerodynamic efficiency. Higher altitude decreases air density, and increased temperature further reduces the air density, resulting in longer takeoff distances.

For many light aircraft, the decrease in air density at altitudes like 4,000 ft combined with a temperature of 90°F will necessitate a longer takeoff distance to clear a 50-foot obstacle compared to lower altitudes or cooler temperatures. In the provided options, a takeoff distance of 2,000 feet is a reasonable expectation under these conditions, as it takes into account the need for a sufficient margin to account for the altitude and temperature impact.

Selecting 2,000 feet as the expected takeoff distance aligns well with standard performance predictions for aircraft taking off under suboptimal conditions of heat and altitude, thereby reinforcing the validity