FAA has issued a safety alert for operators (SAFO) urging flight personnel, training and safety directors to align quick reference handbook (QRH) guidelines with manufacturer-recommended procedures involving the main battery. The SAFO follows an incident on Sept. 22, 2008, where the crew of an American Airlines 737 flying from Seattle to New York experienced an electrical failure. According to the FAA alert, the crew correctly followed the QRH in isolating four electrical busses from the rest of the electrical system. But the procedure also deactivated the main battery charger, and subsequently the main battery became the sole power source for the four isolated busses. The crew decided to continue with the configuration and while enroute to New York, the main battery lost power and failed, forcing an emergency landing in Chicago. FAA notes that other instances of electrical faults leading to battery power loss have occurred in recent history, causing concern among crews, manufacturers and regulators. The SAFO requires operators to “review additional, irregular, non-normal and emergency procedures regarding electrical difficulties” to ensure that the QRH complies with the manufacturer’s recommended guidelines in the aircraft flight manual (AFM). In addition, operators should re-examine or establish rules “that supplement any QRH electrical loss procedure to include consideration of diversion, planning landings on the longest available runway, and preparations for equipment loss.”
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