Atlantic Southeast Airlines Flight 4690
Canadair CL-600-2B19 · Incident: airframe, component or system failure en route
From Hartsfield Jackson Atlanta International Airport (ATL) to Montreal / Pierre Elliott Trudeau International Airport (CYUL)
Event
- NTSB case
- ATL03IA090
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Incident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- Airline
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Canadair CL-600-2B19
- Aircraft type
- Canadair CL-600
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N829AS
- Operator
- Atlantic Southeast Airlines
- Onboard fatalities
- Unknown
- Route
- From Hartsfield Jackson Atlanta International Airport (ATL), Atlanta, GATo Montreal / Pierre Elliott Trudeau International Airport (CYUL), Montreal
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 121: Air Carrier
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- En route · climb to cruise
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Airframe, component or system failure
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- None
Cause areas
- Flight control, aileron › Worn
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
After takeoff the flight crew heard a high frequency vibration which could be felt in the feet and control column. The engine indicating and alerting system indicated no messages. The vibration was slow and increased in intensity and lasted about 30 seconds. The flight was cleared to 17,000 feet, and the airplane started an uncommanded roll to the right. The first officer disconnected the autopilot and regained control of the airplane. The captain declared an emergency, and was issued a clearance to an alternate airport. The vibrations continued at all airspeeds during the descent and landing. Examination of the airplane revealed the bushings and right aileron inboard and outboard power control unit output link were worn and exceeded the authorized tolerance allowed by the maintenance manual. The aircraft manufacturers inspection procedures for the aileron system backlash check did not require the operator to record the tolerance found during the backlash check.
Probable cause
Excessive wear on the bushings and the right aileron inboard and outboard power control unit output link resulting in the upward movement of the right aileron during cruise climb, uncommanded right roll. A factor in the accident was inadequate maintenance inspection procedure by the aircraft manufacture for the aileron system backlash check performed by the operator. The inspection procedure did not require the operator to record the tolerance found during the backlash check.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ATL03IA090
- Event ID
- 20030516X00677
- Case number
- ATL03IA090
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status, coordinates, damage. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: c5888e678c40605c10f5746aa358976cd971a0a2957d57de9eb619bf881e42c4; retrieved 2026-09-18T15:49:24.788Z.