In icing conditions, if outside temperature > -2 C, what throttle practice is specified?

• A. 60% N1 for 15 seconds every 20 minutes
• B. 70% N1 for 30 seconds every 60 minutes
• C. 70% N1 for 10 seconds every 30 minutes
• D. 50% N1 for 10 seconds every 30 minutes

Answer: (C)

In icing conditions, periodic brief engine run-ups help manage ice on the engine and inlets. When outside air is just above -2 C, ice can still form from visible moisture, and a short, moderate spool-up keeps the engine and anti-ice systems primed without unnecessary wear or fuel burn. The specified practice is to advance to 70% N1 for 10 seconds every 30 minutes. This keeps the compressor and intake surfaces free of ice and reduces the risk of ice-related performance issues, while staying efficient and safe.