Aircraft Accident/Incident Report

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

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 Event Accident
Event Date 2/27/2000
Event Day of the Week Sunday
Time of Event 2100
Event Time Zone Eastern Standard Time
Event Country --
Zipcode of the event site 02901
Event Date Year 2000
Event Date Month 2
MidAir Collision Indicator No
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 airport Off Airport/Airstrip
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation --
Weather Briefing Completeness Unknown
Investigator's weather source Unknown
Time of the weather observation 0
Direction of event from weather observation facility (degrees) 0
Weather Observation Facility ID
Elevation of weather observation facility 0
Distance of event from weather observation facility (units?) 0
Time Zone of the weather observation
Lighting Conditions Night/Dark
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 0
Sky/Lowest/Cloud Conditions Unknown
Sky Condition for Lowest Ceiling Unknown
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 0
Air Temperature at event time (in degrees celsius) --
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) 0
Variable Wind Indicator Unknown
Wind Speed (knots) 0
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) --
Density Altitude (feet) --
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury Serious
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor 11
Injury Total None 371
Injury Total Serious 1
Injury Total All 12
Investigating Agency NTSB
NTSB Docket Number (internal use) 10607
NTSB Notification Source --
NTSB Notification Date Feb 28 2000 12:00AM
NTSB Notification Time 219
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Sep 27 2001 3:26PM
User who most recently changed record NTSB\MONR
Basic weather conditions Instrument Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number GBDXL
NTSB Number NYC00LA085
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 129: Foreign
Type of Flight Plan filed IFR
Flight plan Was Activated? --
Damage None
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Boeing
Aircraft Model 747-236
Aircraft Series Identifier 747-236
Aircraft Serial Number 22305
Certified Max Gross Weight 820000
Aircraft Category Airplane
Aircraft Registration Class Foreign Registered/U.S. Soil
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 394
Number of Engines 4
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection Continuous Airworthiness
Date of Last Inspection Feb 23 2000 12:00AM
Airframe hours since last inspection 59
Airframe Hours 648
ELT Installed No
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name BRITISH AIRWAYS, PLC.
Aircraft Owner Street Address P.O. BOX 365
Aircraft Owner City HARMONDSWORTH
Aircraft Owner State OF
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 certificate None
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation Unknown
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not Scheduled
Indicates Domestic or International Flight International
Operator carrying Pax/Cargo/Mail Passenger/Cargo
Type of Flying (Per_Bus / Primary) Unknown
Second Pilot on Board Yes
Departure Point Same as Event No
Departure Airport Code LHR
Departure City LONDON
Departure State OF
Departure Country
Departure Time 1830
Departure Time Zone GMT
Destination Same as Local Flt --
Destination Airport Code JFK
Destination City JAMAICA
Destination State NY
Destination Country
Specific Phase of Flight Descent
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Sep 8 2001 4:00AM
User who most recently changed record dbo
Since inspection or accident --
Event Location Runway Number and Location 0
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --