Explain compressor surge and how the surge margin is maintained.

• A. Surge is flow reversal due to high pressure; margin maintained by over-bleed.
• B. Surge is a stall in the compressor blades causing noise; margin maintained by thicker blades.
• C. Surge is flow reversal due to low pressure; margin maintained by staying within compressor map, using bleed air, and scheduling.
• D. Surge is a combustion instability phenomenon.

Answer: (C)