Originally Posted by barit1
I think there's an overspeed governor in the HMU - in case all else fails
Quoting my Training Manual
Overspeed Governor
A mechanical overspeed governor can prevent an N2 overspeed condition.
When the overspeed governor senses an N2 overspeed condition, it causes
the bypass valve to open more. When the bypass valve opens more, less fuel
goes to the FMV. This causes the N2 speed to decrease. This is an alternative
N2 overspeed protection from the EEC. The EEC monitors the condition of the
overspeed governor.