ATR 72-600 OVBD VALVE
 

Hey guys,

quick question, maybe somebody knows:

What is the state of the OVBD VALVE (14HR) when the aircraft is completely powered down (batteries off)? Closed or open?

Does the OVBD VALVE perform a self test when the battery switch is turned to on? And if so what does it do and is this triggered by the MFC?

Is there some form of documentation for this from ATR?

Thanks in advance...