michelda
10th Feb 2019, 08:10
Hi guys,
around 1 year ago airbus published an OEB for the emergency elec conf. It said that before slat extension the pilot had to push the rat push button.
After a while they put this action in the summary and they removed the oeb.
Does somebody remember why we have to extend the rat?
thanks
MCDU2
11th Feb 2019, 10:04
ExplanationRecent analyses have demonstrated that on A330 aircraft, if the aircraft is in EMER ELEC configuration and single hydraulic Engine Driven Pump (EDP) operation, the following may cause the loss of the emergency generator: In turbulent weather conditions during approach, the increased hydraulic demand from the flight control system and the emergency generator may not be satisfied when the flight crew sets theLAND RECOVERY pb-sw to ON. As a result, the priority valve may close, and cause the loss of the emergency generator.Therefore, the batteries become the only source that can supply power to the aircraft electrical network.Operational RecommendationsTo supply the aircraft with sufficient green hydraulic power and prevent closure of the priority valve in case of single EDP operation, the flight crew must manually extend the Ram Air Turbine (RAT) before they set theLAND RECOVERY pb-sw to ON, when they apply theELECEMER CONFIG ECAM procedure.Due to the extension of the RAT, the speed must not be less than 140 kt. Therefore, the flight crew must ensure that the approach speed (VAPP) is at least 140 kt and confirm the corresponding landing distance.PROCEDUREApply theELECEMER CONFIG ECAM procedure.For slats extension, before setting theLAND RECOVERY pb-sw to ON, press theRAT MAN ON pb to extend the RAT and resume application of theELECEMER CONFIG ECAM procedure.