You are taking off using a short runway, ideal position of bleed air valves?

• A. Fully open
• B. Partially open
• C. Closed to maximise thrust
• D. Open to maximize cabin pressurization

Answer: (C)

Bleed air valves control the air tapped from the engine’s compressor to feed the environmental control system and anti-ice functions. When these valves are open, some of the high‑pressure air is diverted away from the engine core to the packs, which creates a small drag on the engine and reduces the thrust available for takeoff. On a short runway, every bit of thrust matters, so keeping the bleed air valves closed minimizes this parasitic loss and leaves more air flow for propulsion. You’d reopen or reconfigure them if you need bleed air for cabin conditioning or anti-ice after takeoff, but for the goal of maximizing takeoff performance on a short runway, closing is the best setting.