United Air Lines Flight 603
Airbus Industrie A319-131 · Incident: airframe, component or system failure during takeoff
From Chicago O'Hare International Airport (ORD) to Los Angeles International Airport (LAX)
Event
- NTSB case
- CHI03IA027
- 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
Airbus Industrie A319-131
- Aircraft type
- Airbus A319
- 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
- N804UA
- Operator
- United Air LInes
- Onboard fatalities
- Unknown
- Route
- From Chicago O'Hare International Airport (ORD), Chicago, ILTo Los Angeles International Airport (LAX), Los Angeles, CA
- 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
- Takeoff
- 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
- Minor
Cause areas
- Other maintenance personnel › Maintenance, installation, improper
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The airplane landed with the nose wheels turned 90 degrees to the direction of travel. The flight crew was unable to retract the landing gear after takeoff. They received the L/G SHOCK ABSORBER FAULT and AUTO FLT A/THR OFF messages on the electronic centralized aircraft monitoring (ECAM) system. In addition, they had a Nose Wheel Steering message on the landing gear ECAM page. Unable to rectify the problem, the captain elected to return to land at ORD. The captain reported that he did not have any problem controlling the airplane during the landing. During the landing roll, he was informed by the control tower that there were sparks coming from the nose gear. The airplane stopped on the runway and the passengers were deplaned. Post-incident inspection revealed the nose landing gear (NLG) wheels were turned 90 degrees to the left, both of the tires were blown, and the left side tire rim was ground down to the axle. The right side tire rim was nearly ground down to the axle. The incident occurred on the fourth flight following a maintenance "C" check where the dynamic seals inside the nose landing gear (NLG) shock absorber had been replaced. The maintenance was performed by a contract facility. Inspection and teardown of the nose gear revealed the shock absorber had been assembled and installed in the airplane incorrectly during the C-check. This resulted in the anti-rotation lugs on the shock absorber, not being properly seated in the back plate slots. Following this incident, the back plate manufacturer has redesigned the back plate (waiting manufacturer and DGAC approval), the operator has revised their job instruction cards for disassembly and assembly of the NLG shock absorber, and the aircraft manufacturer has revised the Aircraft Maintenance Manual.
Probable cause
The maintenance facililty improperly assembled and installed the nose landing gear shock absorber assembly. Factors were the improper assembly which allowed the nose gear to turn 90 degrees to the direction of travel.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI03IA027
- Event ID
- 20021125X05520
- Case number
- CHI03IA027
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (5)
- 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. 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: 2a81264b8b474baa3d632b319450da65beaed714741e48f92e2461d8d1375207; retrieved 2026-09-18T15:56:56.145Z.
- The NTSB's operator name is blank for N804UA; the operator shown is the name the NTSB records it doing business as.