Air Wisconsin Dornier 328-100 accident
Dornier 328-100 · Accident: gear retraction on ground during landing
From Bismarck Municipal Airport (BIS) to Denver International Airport (DEN)
Event
- NTSB case
- DEN00FA063
- 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
- Accident
- 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
Dornier 328-100
- Aircraft type
- Dornier 328
- 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
- N329MX
- Operator
- Air Wisconsin
- Onboard fatalities
- Unknown
- Route
- From Bismarck Municipal Airport (BIS), Bismarck, NDTo Denver International Airport (DEN)
- 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
- Landing · landing roll
- 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
- Gear retraction on ground
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Reason for occurrence undetermined
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
During the approach, the flight crew confirmed the landing gear was down and locked. The first officer landed the airplane on runway 35L in a slight left crosswind. When the airplane touched down, the landing gear warning horn sounded. The right main and nose landing gears retracted, and the airplane slid to a halt on the right side of the runway. According to the flight data recorder, the landing gear was extended and indicated down and locked (source data is the position of the nose landing gear). The nose landing gear became "unlocked" (i.e., unsafe) 2 seconds after the radio altitude reached 0 feet. Hydraulic pressure dropped to approximately 2,700 psi momentarily, then returned to normal (about 3,000 psi). The following items were subjected to various tests and no anomalies were noted: proximity switch electronics unit (PSEU), right main landing gear harness and proximity switches, landing gear selector valve, hydraulic pressure sensing valve, landing gear control assembly. Hydraulic fluid samples drawn from the filter pack, right main landing gear down lock assist actuator, and the return line for the landing gear selector valve were analyzed. No significant anomalies were noted. Partial systemic wiring tests were unremarkable.
Probable cause
uncommanded retraction of the nose and right main landing gears during landing roll for reasons undetermined.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record DEN00FA063
- Event ID
- 20001212X20609
- Case number
- DEN00FA063
- 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. 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: 0096d11c8405473a74d72f2a94d085ba91e2339d7618275d2769d96e315796f1; retrieved 2026-09-18T16:44:04.740Z.