NOT a max transient engine parameter?

NOT a max transient engine parameter?

• A. 106% N1
• B. 106% N2
• C. 950 ITT
• D. 30 sec

Answer: (D)

During a transient, the limits you actually monitor are numerical values for engine parameters. N1 and N2 are engine speeds expressed as a percent; allowing up to 106% for either means the engine can briefly overspeed to that level during a transient. ITT is a temperature limit, with 950 degrees C indicating the maximum allowable turbine inlet temperature during the transient. The 30-second figure is a duration, not a parameter value. It doesn’t specify a physical state of the engine like speed or temperature; it simply notes how long a transient condition may be allowed. Because it isn’t a parameter value, it isn’t a max transient engine parameter.

During a transient, the limits you actually monitor are numerical values for engine parameters. N1 and N2 are engine speeds expressed as a percent; allowing up to 106% for either means the engine can briefly overspeed to that level during a transient. ITT is a temperature limit, with 950 degrees C indicating the maximum allowable turbine inlet temperature during the transient.

The 30-second figure is a duration, not a parameter value. It doesn’t specify a physical state of the engine like speed or temperature; it simply notes how long a transient condition may be allowed. Because it isn’t a parameter value, it isn’t a max transient engine parameter.