CEN21LA232 · Cirrus Design Corp SR22
Cirrus Design Corp SR22 · Accident: flight instrument malfunction/failure en route
From Sheboygan County Memorial Airport (KSBM) to Burlington Municipal Airport (KBUU)
Event
- NTSB case
- CEN21LA232
- 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
- Event fatalities
- Unknown
- 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
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Instrument Meteorological Cond
Cirrus Design Corp SR22
- Aircraft type
- Cirrus SR22
- 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
- N4144B
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Sheboygan County Memorial Airport (KSBM), Sheboygan, WITo Burlington Municipal Airport (KBUU), Burlington, WI
- Aircraft age
- About 20 years (built 2001)
- 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 91: General Aviation
- 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
- Defining eventThe 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
- Flight instrument malfunction/failure
- 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
- Aircraft › Aircraft systems
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The pilot reported that, during an instrument flight rules flight, he began receiving conflicting information from the flight instruments and digital flight information display. He stated that the turn coordinator and GPS were displaying opposite information, the heading bug was moving erratically, and he felt as if he was flying in circles. After determining that he could not rely on the information from the flight instruments, he elected to activate the Cirrus airframe parachute system. The airplane came to rest in a stand of trees, resulting in substantial damage.
Postaccident testing of the electronic horizonal situation indicator, directional gyro, and horizon reference indicator revealed no anomalies except for the directional gyro counterclockwise heading stability, which exceed the testing limits by about 3°. The heading stability finding, although outside the testing limits, would not result in the instrument anomalies reported by the pilot. The reason for the flight instrument disagreement/malfunction could not be determined based on the available information.
Probable cause
An inflight instrument malfunction for reasons that could not be determined based on available information, which led to the pilot’s decision to activate the airframe parachute system.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN21LA232
- Event ID
- 20210524103136
- Case number
- CEN21LA232
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
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: local date, investigation status, coordinates, cause areas. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2021-05-16.
- API snapshot SHA-256: c7cf65df43d6b09e40b51ab02a2b77c2c4735df1a0d95ac17769d7d867919991; retrieved 2026-09-16T14:04:55.679Z.