Avianca is preparing to appeal a ruling issued by Colombia’s civil aviation regulatory authority, Aerocivil, blocking its proposed merger with low-fares airline Viva. Prior to the proposed merger Viva was owned by Irelandia, an investment company led by Declan Ryan, a founding partner in the airline which has made flying accessible to millions of Colombians.  In April, Avianca said it was hoping to merge with Viva in a holding company called Abra, which plans to become a new regional airline champion and also include Brazil’s Gol airlines. However, Aerocivil said on Wednesday: “According to the law, a merger such as…