Aviation expert: Impossible to say Boeing 737 MAX 8 is safe

U.S. aviation experts have convened at the crash site of Ethiopian Airlines Flight 302 amid growing global concern about the safety of Boeing’s 737 MAX 8 jet. Although dozens of countries have grounded the planes, the FAA says they're safe. John Yang reports and discusses with Mary Schiavo, a former Transportation Department inspector general who represents the victims of airline accidents.