ZANL188 From United States of America, joined Oct 2006, 3680 posts, RR: 0 Posted (6 years 5 months 3 weeks 5 days 15 hours ago) and read 7466 times:
I didn't follow this incident at the time.... Seems to have been sporty.... Good to know that the battery will last 1+40 vs just 30 minutes... Will be interesting to hear how they came around to testing it though...
"On September 22, 2008, at 1342 central daylight time, a Boeing 757-223, N197AN, operated by American Airlines as flight 268, diverted to Chicago O’Hare International Airport (ORD) due to electrical system anomalies. During the landing on runway 22R (7,500 feet by 150 feet), the airplane veered off the left side of the runway resulting in minor damage to the landing gear. There were no injuries to the 2 flight crew, 5 flight attendants, or 185 passengers. The domestic passenger flight was being operated under the provisions of Title 14 Code of Federal Regulations Part 121. Visual meteorological conditions prevailed and an instrument flight rules flight plan was filed. The flight originated from the Seattle-Tacoma International Airport (SEA), Seattle, Washington, at 0802 pacific daylight time, with an intended destination of the John F. Kennedy International Airport (JFK), New York, New York.
While en route the flightcrew received an AIR/GRD SYS message, an illumination of the standby power bus OFF light, and several advisory and status messages on the engine indicating and crew alert system (EICAS). The flight crew then referenced the quick reference handbook (QRH) regarding the AIR/GND SYS message. The flight crew then followed the procedure referenced in the QRH for STANDBY BUS OFF by turning the standby power selector to the BAT position. The QRH procedure also referenced that, "The battery will provide bus power for approximately 30 minutes." The airplane systems stabilized with several items inoperative and the captain contacted maintenance technical support and subsequently elected to continue the flight on battery power. The flightcrew then reviewed the MAIN BATTERY CHARGER procedure referenced in the QRH.
Approximately 1 hour and 40 minutes later, while in cruise flight, the battery power was depleted at which time several cockpit electrical systems began to fail. The airplane was over western Michigan and the captain elected to turn around and divert to ORD. Also, the flight attendants discovered that public address (PA) and the cabin/cockpit interphone systems were inoperative. A flight attendant wrote a note and slipped it under the cockpit door to inform the flight crew of their communication problems. A short time later, the cabin crew was informed that they were diverting to ORD. One of the flight attendants then walked through the aisle informing the passengers of the unscheduled landing at Chicago.
While aligned with the runway to land, the flightcrew declared an emergency with the control tower as a precaution. As the airplane neared the runway on final approach, the flightcrew discovered that the elevator and standby elevator trim systems were inoperative. The captain then assisted the first officer on the flight controls and the approach to land was continued. The systems required to slow the airplane on the runway appeared to indicate normal, and with the elevator control issues the flightcrew did not want to perform a go-around to land on a longer runway. Pitch control of the airplane was difficult so the flightcrew elected to stop the flap extension at 20 degrees. The touchdown was smooth despite the control issues, however, the thrust reversers and spoilers did not deploy. The captain attempted to manually deploy the thrust reversers, but still was not sure if they deployed. The captain was concerned about the brake functionality and accumulator pressure so he made one smooth application of the brakes, which did not “perform well.” Due to obstructions off the end of the runway, the captain elected to veer the airplane off the left side of the runway into the grass.
As the airplane touched down approximately 2,500 feet down the runway witnesses heard loud pops. Skid marks from the left main gear were evident near the point of touchdown and 165 feet further down the runway skid marks from the right main gear were present. These skid marks were visible for the entire length of the runway up until the airplane departed the pavement. The airplane came to rest with all three main landing gear off the left side of the pavement and the nose of the airplane came to rest approximately 100 feet prior to the end of the blast pad pavement which extended 397 feet past the departure end of the runway.
After coming to a stop, the flightcrew was not able to shut the engines down with either the fuel cutoff valves or by extending the fire handles. The engines were subsequently shutdown by depressing the fire handles. The passengers were then deplaned through the L1 and R4 doors using portable stairs.
Post incident investigation revealed a failure of the B1/B2 contacts in the K106 electrical relay. With the standby power selector in the AUTO position, this failure would have resulted in a loss of power to the battery bus and the DC standby bus, which would have resulted in the AIR/GND SYS message and illumination of the standby power bus OFF light which the flight crew received.
With the standby power selector in the BAT position, as selected by the flight crew, the main battery provided power to the hot battery bus, the battery bus, the AC standby bus, and the DC standby bus. In addition, the main battery charger was not receiving power, and thus the battery was not being recharged. When main battery power was depleted, all 4 of the aforementioned buses became unpowered."
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OPNLguy From , joined Dec 1969, posts, RR:
Reply 1, posted (6 years 5 months 3 weeks 5 days 14 hours ago) and read 7392 times:
Quoting ZANL188 (Thread starter): I didn't follow this incident at the time.... Seems to have been sporty.... Good to know that the battery will last 1+40 vs just 30 minutes... Will be interesting to hear how they came around to testing it though...
I agree, it will be interesting to watch. The entire episode recalls that 767 that went into BOS a few years ago and blew all the main tires on landing.
Saw this elsewhere, purportedly issued to AA's crews:
SUBJ: NEW ELECTRICAL CHECKLISTS
A RECENT FLIGHT DIVERTED INTO ORD AFTER COMPLETELY DISCHARGING THE BATTERY AT Macedonian Airlines (Greece)">IN FLIGHT. THE CREW FOLLOWED THE CHECKLISTS CORRECTLY WHICH COME DIRECTLY FROM BOEING AND DID NOT DIRECT THE CREW TO LAND AT THE NEAREST SUITABLE AIRPORT. I WILL BE ISSUING A PINK BULLETIN THAT WILL REPLACE YOUR CURRENT QRH TABS 9 AND 10 CHECKLISTS AS WELL AS THE ENTIRE ELEC SECTION CHECKLISTS. MOST IMPORTANTLY, THESE NEW CHECKLISTS WILL DIRECT THE CREW TO LAND THE AIRCRAFT AT THE NEAREST SUITABLE AIRPORT
IF THE BATTERY IS DISCHARGING AS WELL AS ADD A LIST OF ALL ITEMS ON THE STANDBY AC, STANDBY DC, BATTERY BUS AND HOT BATTERY BUS. YOU WILL SEE THESE CHECKLIST REVISIONS SOON.
Md94 From United States of America, joined Oct 2006, 149 posts, RR: 0
Reply 2, posted (6 years 5 months 3 weeks 5 days 11 hours ago) and read 7067 times:
People I work with witnessed the incident while waiting to take off and said it was a pretty amazing to watch it all unfold on the ground. I had just taken off on another flight a few minutes before this so I missed it.
Revelation From United States of America, joined Feb 2005, 13501 posts, RR: 25
Reply 3, posted (6 years 5 months 3 weeks 4 days 17 hours ago) and read 5686 times:
If I may, a few somewhat naive questions below. Sorry in advance if anyone is offended by them...
Quoting ZANL188 (Thread starter): The QRH procedure also referenced that, "The battery will provide bus power for approximately 30 minutes." The airplane systems stabilized with several items inoperative and the captain contacted maintenance technical support and subsequently elected to continue the flight on battery power. The flightcrew then reviewed the MAIN BATTERY CHARGER procedure referenced in the QRH.
Not sure what to make of this.
The crew knew they were running on battery and weren't sure engines were charging the battery? Or they did think the engines were charging the batteries and so it'd be fine to continue the flight?
Does the aircraft provide the instrumentation one would need to determine if the batteries were indeed being charged?
Quoting ZANL188 (Thread starter): While aligned with the runway to land, the flightcrew declared an emergency with the control tower as a precaution. As the airplane neared the runway on final approach, the flightcrew discovered that the elevator and standby elevator trim systems were inoperative.
Is it unusual to declare an emergency while on final approach?
The wording is confusing: surely it is just the trim system that was inop, not the elevator itself?
Wouldn't it have been feasible to test the trim system at altitude so you wouldn't find out about the problem while on final?
Quoting ZANL188 (Thread starter): After coming to a stop, the flightcrew was not able to shut the engines down with either the fuel cutoff valves or by extending the fire handles. The engines were subsequently shutdown by depressing the fire handles.
Doesn't that pretty much guarantee a costly rebuild of the engines?