Federal auditors are issuing fresh criticism of the government agency that approved the Boeing 737 Max. The Transportation Department’s inspector general said Wednesday that the Federal Aviation Administration must improve its process for certifying new planes. The auditors say the FAA didn’t understand a key flight-control system that played a role in two deadly crashes of Boeing Max jets. They also say the FAA doesn’t properly deal with integrating new technologies into existing planes. They also say the FAA suffers from weak management and oversight.