The ISOV Air Intake Shutoff Valves with Mechanical Failsafe actuation has an electrically powered 2/3 valve. This valve supplies the ISOV failsafe with engine oil pressure, which keeps the ISOV failsafe open during operation.
When the power is lost, the 2/3 valve will shut off the engine oil pressure and the pressure leading to the valve will be vented, causing the pressure in the ISOV Failsafe to drop and the gate to close. This will stop the supply of intake air to the engine, effectively bringing engine to a halt. This is an ideal solution to help control engines in emergency situations where electric supply is lost frequently.