While under pilotage Main Engine slowdown occurred after following alarms :
- SUPERV. CH30 , 4102, ELFI/FIVA POSITION
- EXH VALVE OPEN
- ILLEGAL ELFI/FIVA POSITION STROKE LOW
- ELFI FIVA FEEDBACK SENSOR FAILURE
What is most likely causes slowdown?
Most likely FIVA valve has failed.
To confirm, replace it with new or swap from other unit in case there is no spare valve in stock.