If the temperature is 50 °F, pressure altitude is sea level, weight is 3,000 lb, and headwind is 10 kts, what is the approximate ground roll?

To determine the approximate ground roll for an aircraft under the specified conditions, one must consider several factors: temperature, pressure altitude, aircraft weight, and wind effects.

In this scenario, the temperature is 50 °F, which is relatively warm and could be a bit off the standard temperature. While being at sea level, the air density and performance characteristics will largely adhere to standard performance charts. The pressure altitude being at sea level ensures that the aircraft is operating in a denser air environment, which is favorable for shorter takeoff distances.

The weight of 3,000 lb suggests a moderate-sized aircraft. With a headwind of 10 knots, the effective groundspeed at which the aircraft accelerates is reduced, benefiting the ground roll distance as the headwind provides an additional lift component.

When calculating the ground roll, pilots typically refer to performance charts or models that accommodate these inputs. Given these specifics and working with standard performance data for light aircraft, the calculated ground roll leans toward approximately 636 feet.

Therefore, the answer of 636 feet reasonably matches performance expectations based on the described conditions and represents an accurate assessment when considering all the contributing factors affecting takeoff and ground roll distances.