In a high bypass turbofan engine, what is the function of the reverse thrust system?

• A. To generate thrust during landing
• B. Blocker doors divert cold stream air
• C. To increase core pressure
• D. To close the bypass duct

Answer: (B)

In a high bypass turbofan, the reverse thrust system uses the bypass airflow (the cold air around the engine core) to help slow the aircraft after landing. It accomplishes this by placing blocker doors in the bypass duct to block the normal forward flow and redirect that air forward through thrust-reverser cascades or vanes. The redirected air exits forward, creating a braking force opposite the aircraft’s motion. This relies on diverting the cold bypass air, not on boosting core pressure, generating thrust during landing, or closing the bypass duct.