When outside temperature is between -2 C and -9 C in icing conditions, what is the maximum total time for throttle N1 usage?

When outside temperature is between -2 C and -9 C in icing conditions, what is the maximum total time for throttle N1 usage?

• A. 2 hours
• B. 1 hour
• C. 30 minutes
• D. 45 minutes

Answer: (B)

In icing conditions, there are time limits on how long you can operate at higher N1 to protect the engine and manage ice buildup. When the outside air temperature is between -2 C and -9 C, ice can accumulate on the engine inlet and related components in a way that high-N1 operation helps counter, but sustained high power also increases engine load, heat, and wear. To balance protection with engine health, the procedure allows a total of one hour of N1 usage in this temperature band. After that, you should transition to other anti-ice methods or reduce exposure to icing conditions as procedures dictate.

In icing conditions, there are time limits on how long you can operate at higher N1 to protect the engine and manage ice buildup. When the outside air temperature is between -2 C and -9 C, ice can accumulate on the engine inlet and related components in a way that high-N1 operation helps counter, but sustained high power also increases engine load, heat, and wear. To balance protection with engine health, the procedure allows a total of one hour of N1 usage in this temperature band. After that, you should transition to other anti-ice methods or reduce exposure to icing conditions as procedures dictate.