Northwest Airlines Flight 1412
McDonnell Douglas DC-9-51 · Incident: airframe, component or system failure during takeoff
From Chicago Midway International Airport (MDW) to Detroit Metropolitan Wayne County Airport (DTW)
Event
- NTSB case
- CHI00IA009
- 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
- 0
- 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
McDonnell Douglas DC-9-51
- Aircraft type
- McDonnell Douglas DC-9
- 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
- N766NC
- Operator
- Northwest Airlines
- Onboard fatalities
- Unknown
- Route
- From Chicago Midway International Airport (MDW)To Detroit Metropolitan Wayne County Airport (DTW), Detroit, MI
- 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 · roll/run
- 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
- Company maintenance personnel › Maintenance, installation, improper
- Landing gear, wheel › Separation
- Manufacturer › Condition(s)/step(s) not listed
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
A DC-9-51 sustained a left outboard main (#1 main) wheel and tire assembly separation on takeoff. That wheel impacted and dislodged the airport's perimeter wall and impacted a vehicle on a nearby road. The wall panels impacted another vehicle. No injuries were reported. The flight landed without incident at its intended destination. That tire assembly was found pressurized and its hubcap was found intact. Its axle nut was found intact under the hubcap. The interior portion of the #1 axle was examined and its internal threads were found intact. The anti-skid transducer adapter was found loosened inside the axle's threads and backed out 4 1/2 turns. A gap was designed to exist between the adapter and the nut. The axle nut was found to contact the adapter when the adapter was backed out to the position as found. The tire was changed on October 1, 1999. The mechanics installed the wheel in accordance with manual 32-40-1. That manual was reviewed and its steps did not caution mechanics to check for the proper depth of the adapter. DC-9-20 through 40 series airplane's anti-skid transducer assemblies were initially secured in position through safety wire. Service Bulletin (SB) 32-111 was issued to incorporate a set screw method in lieu of safety wiring the anti-skid transducer in place. This airplane's SB 32-111 modification was incorporated prior to its delivery to the airline. Subsequent to the incident, the manufacturer issued temporary service bulletins to the affected airplane's 32-40-01 maintenance manuals, cautioning mechanics to check the depth dimension of the transducer adapter with reference to the applicable technical data.
Probable cause
The landing gear's wheel separation due to the improper installation of the wheel by company maintenance personnel using incomplete maintenance steps, and the maintenance steps not listed in the manufacturer's manual. Factors were the airport perimeter wall and the vehicles.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI00IA009
- Event ID
- 20001212X19913
- Case number
- CHI00IA009
- 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, 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: 0ac3a8cda22f6e6c6ebb310526d06a29a07195159db698650500f19b8f1f8de9; retrieved 2026-09-18T16:52:03.972Z.
- The NTSB's operator name is blank for N766NC; the operator shown is the name the NTSB's other records give its FAA operator code, NWAA.