Qantas A380 uncontained #2 engine failure

[no-hoper]

Overspeed Trent 900

Engine Protection Systems

Introduction
The Protection System is incorporated into the EEC and provides hardware to perform the following functions:
LP & IP Rotor Overspeed protection
LP Turbine Overspeed protection
Thrust Control Malfunction (TCM) protection
LP & IP Rotor Overspeed System
The EEC monitors the LP & IP compressor shaft speeds (N1 & N2). If the measured values are above the defined limits, overspeed of the engine is detected and the engine is automatically shut down.
Turbine Overspeed System (TOS)
The EEC compares the LP compressor speed with the LP Turbine speed. If the speed difference is more than the limit, it is an indication of a shaft breakage and the engine is automatically shutdown.