What type of air seal is used in the sump and turbine areas of a gas turbine engine?

Correct Answer: Option A — Labyrinth-Honeycomb

Labyrinth-honeycomb seals are utilized in high-pressure, high-temperature areas like turbine stages and sumps. The labyrinth design creates a tortuous path for air, while the honeycomb structure minimizes leakage by trapping air vortices, providing a robust, non-contact seal capable of enduring the harsh operating environment of marine turbines.