FAA Powerplant Written Practice Test

What challenge does a divided entrance inlet air duct on a turbine-powered aircraft present?

1. Increased weight of the duct

2. Difficulty in controlling engine temperature

3. Increased drag produced

4. Complexity in maintenance procedures

The correct answer is: Increased drag produced

The challenge presented by a divided entrance inlet air duct on a turbine-powered aircraft primarily revolves around the increase in drag produced. Divided ducts can disrupt airflow and create turbulence, which may lead to an increase in aerodynamic drag. This is particularly significant at higher speeds, where the smooth flow of air is critical for maintaining efficiency and performance. When air is divided and channeled through multiple paths, especially in an engine design intended for high efficiency, it can lead to uneven air distribution and turbulence. As a result, the overall drag experienced by the aircraft may be higher compared to a simpler duct design. Additionally, managing airflow effectively in such configurations can require more sophisticated aerodynamic design considerations, which further contributes to drag. Understanding the implications of duct design is essential for optimizing aircraft performance, particularly in turbine-powered designs where the efficiency of airflow directly influences engine performance and fuel consumption.