really nice build last time i saw FA2 that clean was when it rolled out the factory.
when on the flight line engine shut down only the top half aux intake doors open due to gravity the doors are only hinged no springs or anything to open or close them. when on the ground idling or taxing all the doors are open and only close once enough the aircraft is in forward flight and enough air is passing through the main intake.
As for the undercarrigde the main doors are always closed even when on the ground and only opened for ground crews to gain access and closed once maintenance is complete. if the doors are left open the and the aircraft flies as the undercarridge retracts and breaks the hand operated strut. Have seen this happen several times. The nose doors are open immediately on engine shut down a small ground lock is inserted to prevent the valve being closed and removed untill just before flight normally on pilot preflight walkround. The nose door close under hydraulic pressure of 2800psi as soon engine starts, a hydraulic rig is operating and under accumalator pressures so if not treated with care nasty injuries have occured
any shar questions please as i worked on frs1 and fa2 for 20 years