CEN17CA114 · Cessna 340A A
Signicast Cessna 340A A · Accident: loss of control in flight on approach
From Dodge County Airport (UNU) to Waukesha County Airport (UES)
Event
- NTSB case
- CEN17CA114
- 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
- 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
Cessna 340A A
- Aircraft type
- Cessna 340
- 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
- N255BC
- Operator
- Signicast
- Onboard fatalities
- Unknown
- Route
- From Dodge County Airport (UNU), Juneau, WITo Waukesha County Airport (UES), Waukesha, WI
- Aircraft age
- About 38 years (built 1979)
- 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
- Approach · IFR final approach
- 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
- Loss of control in flight
- 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 oper/perf/capability
- Environmental issues › Conditions/weather/phenomena
- Personnel issues › Action/decision
- Personnel issues › Task performance
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
Before the positioning flight, the airline transport pilot monitored the weather and noticed the weather conditions were deteriorating near the time of the planned departure. The weather conditions included low visibility, freezing drizzle, and mist. In an effort to reduce the time in the deteriorating weather conditions, the pilot performed some before takeoff checks while the airplane was in the hangar. During the pilot's "haste" to preflight and take off, she inadvertently selected the wrong switch for windshield heat. While on the instrument approach to the runway in night conditions, the pilot had no forward visibility due to ice accumulation on the windshield. The pilot executed a missed approach and contacted an instructor pilot at the departure airport to confirm the location of the windshield heat switch. The pilot then activated the windshield heat switch and enough ice had melted for the pilot to conduct another approach. During the approach, the pilot increased the airspeed due to "carrying a lot of ice." On short final approach, the airplane descended below the glidepath due to the ice accumulation. Subsequently, the airplane contacted the terrain short of the runway and then "skipped" onto the runway. The airplane came to rest upright and off the runway surface. Examination of the airplane revealed substantial damage to the left wing. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation.
Probable cause
The pilot’s decision to fly in in conditions conducive to structural icing and her subsequent failure to maintain airplane control during the instrument approach.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN17CA114
- Event ID
- 20170301X20646
- Case number
- CEN17CA114
- 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. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2017-02-25.
- API snapshot SHA-256: 694a88e4557fa61fc3ec289be3def0c045c164cfdf437960b00d25699dec659a; retrieved 2026-09-16T05:03:15.122Z.