- Date
- April 10, 1993, 11:12 local (16:12 UTC)
- Place
- Kansas City, MO
- Injuries
- 101 uninjured
- Damage
- No damage
- Phase of flight
- Enroute
- Aircraft
- CGAUPBoeing 767-233
- Weather
- Visual (VMC) · Day
- Status
- Completed · report May 10, 1994
- Report
- Approved by Office Director
- Case key
- 15597
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the incident.
On this page
Probable cause
A frozen aileron control bearing after it had become worn, corroded and exposed to water, and the manufacturer's inadequate maintenance/inspection requirment of the bearing(s).
Sequence of events
NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.
Analysis
The flight crew noted a loss of aileron control (felt frozen), while cruising at FL 370. They were able to make heading changes by using the rudder & elected to divert to Kansas City (mci). The airplane had been exposed to rain & standing water before the flight. The crew felt the loss of aileron control may have been due to frozen water in the control system. During descent to mci, above freezing air temperatures were encountered, & control of the ailerons gradually returned until full control was regained. An uneventful landing was made at mci. Investigation revealed worn aileron control bearings in the lateral control actuator system. The worn bearings were tested by soaking in water & freezing. Water penetrated a bearing housing & froze inside the bearing race, disabling the bearing. Subsequent disassembly of the bearing disclosed corroded & worn ball bearings. Boeing service letter (767-S-27-094) & sevice bulletin 767-27-0128 were issued to address inspection/replacement criteria of the bearings.
Aircraft
- Registration
- CGAUP
- Reported as
- Boeing 767-233
- Category
- Airplane
- Serial number
- 22521
- Airframe hours
- 32,301
- Engine
- P&W JT9D-7R4D, 48,000 lbs thrust, turbo fan
- Damage
- No damage
- Flight
- Part 129
- Operator
- Air Canada
- Registered owner
- Air Canada
- Airworthiness certificate
- Standard, Transport
- Last inspection
- Continuous airworthiness · January 2, 2000
- Departed
- SFO · San Francisco, CA
- Destination
- YYZ · Toronto
- Flight plan
- IFR
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Certificate
- Airline transport
- Airplane ratings
- Multi-engine land
- Instrument ratings
- Airplane
- Medical
- Unknown, Unknown
- Seat
- Left
Weather
- Conditions
- Visual (VMC) · Day
- Visibility
- 50 statute miles
- Lowest ceiling
- None
- Temperature
- -69 °F
- Altimeter
- 29.00 inHg