Aircraft Incident/Accident Report

Providence, Rhode Island 02901
Sunday, February 27, 2000 21:00 EST

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NTSB Narrative Summary Released at Completion of Accident
The airplane was in cruise flight when it began a descent from flight level 350. At the same time, the flight engineer was reconfiguring the airplane's electrical system from a Category III landing to a Category I landing. When the flight engineer closed the "number one bus-tie-breaker," the airplane experienced an uncommanded pitch-up, accompanied by numerous momentary instrument failures. Twelve occupants were injured. The airplane was utilizing the "A" autopilot system, which remained engaged. The pilot disconnected the autopilot, leveled the airplane, re-engaged the autopilot, and continued to an uneventful landing. During a ferry flight, maintenance personnel were able to duplicate a "sudden pitch-up" while using the airplane's "B" autopilot system, and closing the "number two bus-tie-breaker." Additionally, the flight crew reported that the airplane "felt light in pitch." Examination of data obtained from the flight data recorder and optical quick access recorder revealed an electrical discontinuity around the time of the pitch-up. An inspection of the airplane revealed that the number 1 and 2, elevator feel computer pitot connections were capped. Review of the airplane's maintenance history revealed that the airplane had recently undergone an "inter 2 check" at a British Airways maintenance facility. During that time, maintenance personnel disconnected the pitot connections to the elevator feel computer in order to perform pitot static system checks. The effect of the disconnected pitot-static lines on the elevator feel computer would have resulted in a more extreme travel of the elevator control surface. The calculated expected autopilot elevator authority for the accident flight was about 4 degrees. The estimated actual elevator deflection during the accident sequence was 6.87 degrees nose up, and 6.97 degrees nose down. Review of the Boeing basic airplane maintenance manual section that detailed the pitot-static system checks revealed a test to confirm that the elevator feel computer was reconnected and functioned. The test was not present the maintenance manual utilized by British Airways, which was provided by Boeing. The source of the pitch-up command to the autopilot was not determined; however, when the autopilot system was properly configured, the pitch-up characteristics were not objectionable and within expected values.
NTSB Probable Cause Narrative
Maintenance personnel's failure to reconnect the pitot connections to the elevator feel computer which resulted in an elevator control surface deflection which was outside of the normal autopilot elevator authority. The uncommanded autopilot input to the elevator control surface resulted from an undetermined electrical source. A factor in this accident was that the section of the 747 Maintenance Manuel utilized by company maintenance personnel did not contain an "elevator feel light test."
Event Information
Type of EventAccident 
Event Date2/27/2000 
Event Day of the WeekSunday 
Time of Event2100 
Event Time ZoneEastern Standard Time 
Event Country-- 
Zipcode of the event site02901  
Event Date Year2000 
Event Date Month
MidAir Collision IndicatorNo 
On Ground Collision occurred ?No 
Event Location Latitude-- 
Event Location Longitude-- 
Event Location Airport  
Event Location Nearest Airport ID  
Indicates whether the acc/inc occurred off or on an airportOff Airport/Airstrip 
Distance from airport in statute miles-- 
Degrees magnetic from airport-- 
Airport Elevation-- 
Weather Briefing CompletenessUnknown 
Investigator's weather sourceUnknown 
Time of the weather observation0  
Direction of event from weather observation facility (degrees)
Weather Observation Facility ID  
Elevation of weather observation facility
Distance of event from weather observation facility (units?)
Time Zone of the weather observation  
Lighting ConditionsNight/Dark 
Lowest Ceiling Height
Lowest Non-Ceiling Height
Sky/Lowest/Cloud ConditionsUnknown 
Sky Condition for Lowest CeilingUnknown 
Visibility Runway Visual Range (Feet)
Visibility Runway Visual Value (Statute Miles)
Visibility (Statute Miles)
Air Temperature at event time (in degrees celsius)-- 
Dew Point at event time (in degress fahrenheit)-- 
Wind Direction (degrees magnetic)
Variable Wind IndicatorUnknown 
Wind Speed (knots)
Wind Velocity Indicator Unknown 
Wind Gust IndicatorUnknown 
Wind Gust (knots)
Altimeter Setting at event time (in. Hg) -- 
Density Altitude (feet)-- 
Intensity of PrecipitationUnknown 
METAR weather report -- 
Event Highest InjurySerious 
On Ground, Fatal Injuries
On Ground, Minor Injuries
On Ground, Serious Injuries
Injury Total Fatal-- 
Injury Total Minor11 
Injury Total None371 
Injury Total Serious
Injury Total All12 
Investigating AgencyNTSB 
NTSB Docket Number (internal use)10607 
NTSB Notification Source-- 
NTSB Notification DateFeb 28 2000 12:00AM 
NTSB Notification Time219 
Fiche Number and/or location -used to find docket informationIMAGE 
Date of most recent change to recordSep 27 2001 3:26PM 
User who most recently changed recordNTSB\MONR  
Basic weather conditionsInstrument Meteorological Cond 
FAA District Office-- 
Aircraft Involved
Aircraft #1
Aircraft Registration NumberGBDXL 
NTSB NumberNYC00LA085  
Missing Aircraft Indicator
Federal Aviation Reg. PartPart 129: Foreign 
Type of Flight Plan filedIFR 
Flight plan Was Activated?-- 
Aircraft FireNone 
Aircraft ExplosionNone 
Aircraft Manufacturer's Full NameBoeing  
Aircraft Model747-236  
Aircraft Series Identifier747-236  
Aircraft Serial Number22305  
Certified Max Gross Weight820000 
Aircraft CategoryAirplane 
Aircraft Registration ClassForeign Registered/U.S. Soil 
Aircraft is a homebuilt?No 
Flight Crew Seats-- 
Cabin Crew Seats-- 
Passenger Seats-- 
Total number of seats on the aircraft394 
Number of Engines
Fixed gear or retractable gearRetractable 
Aircraft, Type of Last InspectionContinuous Airworthiness 
Date of Last InspectionFeb 23 2000 12:00AM 
Airframe hours since last inspection59 
Airframe Hours648 
ELT InstalledNo 
ELT ActivatedUnknown 
ELT Aided Location of Event SiteUnknown 
ELT Type-- 
Aircraft Owner NameBRITISH AIRWAYS, PLC.  
Aircraft Owner Street AddressP.O. BOX 365  
Aircraft Owner CityHARMONDSWORTH  
Aircraft Owner StateOF 
Aircraft Owner Country  
Aircraft Owner Zipcode  
Operator is an individual?-- 
Operator Name  
Operator Same as Owner?Yes 
Operator Is Doing Business As-- 
Operator Address Same as Owner?Yes 
Operator Street Address  
Operator City  
Operator State  
Operator Country  
Operator Zip code  
Operator Code  
Owner has at least one certificateNone 
Other Operator of large aircraft?No 
Certified for Part 133 or 137 OperationUnknown 
Operator Certificate Number-- 
Indicates whether an air carrier operation was scheduled or notScheduled 
Indicates Domestic or International FlightInternational 
Operator carrying Pax/Cargo/MailPassenger/Cargo 
Type of Flying (Per_Bus / Primary)Unknown 
Second Pilot on BoardYes 
Departure Point Same as EventNo 
Departure Airport CodeLHR  
Departure CityLONDON  
Departure StateOF 
Departure Country  
Departure Time1830 
Departure Time ZoneGMT 
Destination Same as Local Flt-- 
Destination Airport CodeJFK  
Destination CityJAMAICA  
Destination StateNY 
Destination Country  
Specific Phase of FlightDescent 
Report sent to ICAO?-- 
Evacuation occurred-- 
Date of most recent change to recordSep 8 2001 4:00AM 
User who most recently changed recorddbo  
Since inspection or accident-- 
Event Location Runway Number and Location0  
Runway Length-- 
Runway Width-- 
Sight Seeing flightNo 
Air Medical FlightNo 
Medical Flight--