On June 16, captain Valerie Wells, a 30-year-pilot, was scheduled to fly an Airbus A330, which can carry nearly 300 passengers, on a flight from Philadelphia to Rome. But she declined to fly because of failures of both the auxiliary power unit, a backup source of electrical power, and the "hot battery bus," a primary source of electrical power.
After the crew and passengers had returned to the gate Wells, in a particularly unusual event, was escorted out of the airport by security officials. Subsequently, a second crew of three pilots also declined to fly; the aircraft was repaired and underwent a rigorous inspection, and a third crew took off about six to seven hours late.
