CHI98FA159 · Bell 206L-1
Bell 206L-1 · Accident: loss of control in flight while maneuvering
From Waukegan National Airport (UGN) to an unrecorded destination
Event
- NTSB case
- CHI98FA159
- 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
- 4 · 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
- General aviation
- 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
Bell 206L-1
- Aircraft type
- Bell 206
- Category
- Helicopter
- 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
- N41BL
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Waukegan National Airport (UGN), Waukegan, ILTo not recorded
- 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 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
- Maneuvering
- 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
- 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
- Destroyed
Cause areas
No findings designated as a cause are recorded in the NTSB data yet.
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
A witness observed the helicopter fly over his apartment building within 100 feet. He watched the helicopter travel away from the building on a southwesterly heading in a level attitude. The witness estimated the helicopter to be approximately 350 feet above the ground. The witness said he saw the helicopter begin a slow banked turn to the left toward a southerly heading. The helicopter banked through 30 degrees up to 90 degrees, then it pitched down and descended in a 70 to 80 degree nose-down pitch angle. The witness lost sight of the helicopter when it descended below the tree tops. Another witness in the same building said that as the helicopter was going to the west, it was getting closer to the tree tops. The witness said that the helicopter 'banked real hard [to the] south, so that the [main rotor] blades were perpendicular to the ground. The helicopter went straight down in a dive, nose first.' The witness said that the helicopter was only 15 feet above the tree tops when it dove in. Examination of the wreckage revealed no anomalies. The results of FAA toxicology testing of specimens from the pilot revealed 0.007 (ug/ml, ug/g) chlorpheniramine detected in urine.
Probable cause
Loss of helicopter control for unknown reasons.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI98FA159
- Event ID
- 20001211X09996
- Case number
- CHI98FA159
- 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: 5ec8d80ec75b21be5ecc5932800ee4af3e7a879634a95170820cfeaed8f0c3d2; retrieved 2026-09-20T22:35:06.936Z.