CBI on Tuesday (April 23) freezes bank accounts of former IAF Chief S P Tyagi along with other accused in connection with AgustaWestland helicopter deal scam. CBI on Tuesday (April 23) freezes bank accounts of former IAF Chief S P Tyagi along with other accused in connection with AgustaWestland helicopter deal scam. Aeromatrix Info Solutions private limited, an accused firm in the Rs 3600 crore VVIP helicopter deal scam, had moved a Delhi court seeking de-freezing of its bank account for paying salaries to its employees.