Former civil aviation minister and NCP leader Praful Patel appeared before the Enforcement Directorate in connection with a money laundering probe related to losses suffered by Air India as part of an alleged multi-crore aviation scam. Patel has been grilled for about 8 hours. The case emerges from a criminal complaint registered by the Enforcement Directorate (ED) for alleged irregularities in fixing air slots for international airlines that purportedly led to losses for Air India, the national aviation carrier.