Hi Bernd,
Obviously you are well informed in to the logics of this acft. Suppose the crew makes the power check but the acft. is not in the T/O configuration. The Parking brakes are set >The acft is not in the T/O configuration> the T/O warning sounds, >somebody in the cockpit wants to silence the warning and pulls the ground/air CB. Q? Do the parking brakes remain set or not.
John