Seattle-Tacoma Intl Airport
Aircraft Accident/Incident Report

Seattle, Washington 98158
Saturday, September 27, 1997 8:49 PDT

NTSB Narrative Summary Released at Completion of Accident

The crew reported that at liftoff, 'considerable aileron and rudder input' was required to maintain straight and level flight, and that when aileron input was reduced to zero, at least 5 units of left rudder trim was required to maintain wings-level flight. The crew returned to the departure airport and landed without further incident. Postflight troubleshooting revealed that the ABSB-4 right aileron bus cable was broken and the ABSA-4 right aileron bus cable was frayed, both where the cables ride over the right wing/body joint aileron pulleys. Examination of the cables at the NTSB materials laboratory concluded that the ABSB cable failure was the result of severe internal wear due to normal movement of the cable over a pulley for an extended period of time. Examination also noted several areas of severe external wear on the cables. The airplane maintenance manual, which specifies inspection of exposed cables at each 'C' check (approximately once per year), contains procedures for checking cables for broken wires and gauging the extent of external wear. An 'optional as needed' step also specifies cable replacement based on reduction of cable cross sectional area. The airplane received a segmented 'C' check, which included inspection of aileron cables, approximately 6 weeks prior to the incident.

NTSB Probable Cause Narrative

Separation of the ABSB-4 aileron bus cable, resulting in reduced lateral controllability of the aircraft. Related factors were wear in the cable and inadequate inspection of the cable by company maintenance personnel.

Event Information

Type of Event Incident
Event Date 9/27/1997
Event Day of the Week Saturday
Time of Event 849
Event Time Zone Pacific Daylight Time
Event City SEATTLE
Event State WASHINGTON
Event Country --
Zipcode of the event site 98158
Event Date Year 1997
Event Date Month 9
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport SEATTLE-TACOMA INTL
Event Location Nearest Airport ID SEA
Indicates whether the acc/inc occurred off or on an airport On Airport
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation 429
Weather Briefing Completeness Full
Investigator's weather source Weather Observation Facility
Time of the weather observation 756 Pacific Daylight Time
Direction of event from weather observation facility (degrees) 0
Weather Observation Facility ID SEA
Elevation of weather observation facility 429
Distance of event from weather observation facility (units?) 0
Time Zone of the weather observation PDT
Lighting Conditions Day
Lowest Ceiling Height 18000
Lowest Non-Ceiling Height 4500
Sky/Lowest/Cloud Conditions Scattered
Sky Condition for Lowest Ceiling Broken
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 13
Dew Point at event time (in degress fahrenheit) 10
Wind Direction (degrees magnetic) 180
Variable Wind Indicator Unknown
Wind Speed (knots) 15
Wind Velocity Indicator Unknown
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 30
Density Altitude (feet) --
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor --
Injury Total None 134
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 5048
NTSB Notification Source --
NTSB Notification Date Sep 27 1997 12:00AM
NTSB Notification Time 931
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 8 2000 12:34PM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N13331
NTSB Number SEA97IA219
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 121: Air Carrier
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 737-3T0
Aircraft Series Identifier 737-3T0
Aircraft Serial Number 23569
Certified Max Gross Weight 135000
Aircraft Category Airplane
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 134
Number of Engines 2
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection Continuous Airworthiness
Date of Last Inspection Aug 15 1997 12:00AM
Airframe hours since last inspection 378
Airframe Hours 34633
ELT Installed No
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name WILMINGTON TRUST CO.
Aircraft Owner Street Address RODNEY SQUARE NORTH
Aircraft Owner City WILMINGTON
Aircraft Owner State DE
Aircraft Owner Country
Aircraft Owner Zipcode 19890
Operator is an individual? --
Operator Name CONTINENTAL AIRLINES
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address 2929 ALLEN PARKWAY
Operator City HOUSTON
Operator State TX
Operator Country
Operator Zip code 77019
Operator Code CALA
Owner has at least one certificate Yes - certificate holder
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 Domestic
Operator carrying Pax/Cargo/Mail Passenger/Cargo
Type of Flying (Per_Bus / Primary) Unknown
Second Pilot on Board Yes
Departure Point Same as Event Yes
Departure Airport Code SEA
Departure City
Departure State
Departure Country
Departure Time 849
Departure Time Zone PDT
Destination Same as Local Flt --
Destination Airport Code IAH
Destination City HOUSTON
Destination State TX
Destination Country
Specific Phase of Flight --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Dec 20 2002 12:42PM
User who most recently changed record dbo
Since inspection or accident --
Event Location Runway Number and Location 16L
Runway Length 11900
Runway Width 150
Sight Seeing flight No
Air Medical Flight No
Medical Flight --