Former IAF chief S P Tyagi on Wednesday became the first Air Chief to be booked by the CBI, along with 12 others, for alleged cheating, corruption and criminal conspiracy in the Rs 3600-crore VVIP helicopter deal and searches were carried out at 14 locations including his residence. The former Air Chief, his cousins, Sanjeev alias Julie, Rajeev alias Docsa and Sandeep, European middlemen Carlo Gerosa, Christian Michel and Guido Haschke were among 13 individuals named in the FIR as accused, CBI sources said.