Boeing 737-3T0 N13331

Summary

On 27 September 1997 at about 15:49 local time, a Boeing 737-3T0 registered N13331, operated by Continental Airlines, was involved in an incident near Seattle, Washington, United States. 134 people were on board and nobody was injured. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

27 September 1997 at 15:49

Classification

Incident

Location

Seattle, Washington, United States

Nearest airport

Seattle-Tacoma Intl (SEA)

Coordinates

47.4409, -122.3107

Aircraft

Boeing 737-3T0

Registration

N13331

Category

Airplane

Engines

2

Operator

Continental Airlines

Operating rule

Part 121: Air Carrier

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

Unknown → Houston

Aircraft damage

Not recorded

Weather

VMC

Light

Day

NTSB number

SEA97IA219

Nobody was injured.

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.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

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.

Quoted verbatim from the NTSB record.