Which option is NOT a main function of the ECS?

Which option is NOT a main function of the ECS?

• A. Engine thrust control
• B. Cabin pressurization
• C. Temperature control
• D. Air quality management

Answer: (A)

The main idea is understanding what the Environmental Control System is responsible for in keeping the cabin environment safe and comfortable. The ECS handles delivering conditioned air to the cabin, maintaining cabin pressure, regulating cabin temperature, and managing air quality (filters and ventilation). It does not control how much thrust the engines produce. Engine thrust is managed by propulsion and engine control systems, separate from the ECS. On the 787, the ECS is typically bleedless and relies on electric packs, but its job remains to condition and circulate cabin air, not to adjust engine power.

The main idea is understanding what the Environmental Control System is responsible for in keeping the cabin environment safe and comfortable. The ECS handles delivering conditioned air to the cabin, maintaining cabin pressure, regulating cabin temperature, and managing air quality (filters and ventilation). It does not control how much thrust the engines produce. Engine thrust is managed by propulsion and engine control systems, separate from the ECS. On the 787, the ECS is typically bleedless and relies on electric packs, but its job remains to condition and circulate cabin air, not to adjust engine power.