CHI89LA191 · Bell 206B-3
Bell 206B-3 · Accident: partial loss of engine power (mechanical failure) en route
From Chicago Midway International Airport (MDW) to an unrecorded destination
Event
- NTSB case
- CHI89LA191
- 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
- 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 206B-3
- 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
- N9229X
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Chicago Midway International Airport (MDW), Chicago, 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
- En route · cruise
- 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
- Partial loss of engine power (mechanical 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
- Compressor assembly, blade › Failure, total
- Compressor assembly, stator vane › Failure, total
- Terrain condition › High vegetation
- Terrain condition › Rough/uneven
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
THE ACCIDENT HELICOPTER EXPERIENCED AN ENGINE FAILURE AND AUTOROTATED TO AN OPEN FIELD IN AN URBAN AREA DURING A MAINTENANCE TEST FLIGHT. THE HELICOPTER WAS SUBSTANTIALLY DAMAGED WHEN IT LANDED IN, ACCORDING TO THE PILOT, 'A DEEP GRASSY, ROUGH FIELD.' EXAMINATION OF THE ENGINE COMPRESSOR CASE REVEALED PUNCTURES IN SEVERAL LOCATIONS FROM THE INSIDE OUT. WHEN THE COMPRESSOR CASE WAS OPENED ALL BLADES AND VANES AFT ON THE FIRST STAGE WERE DAMAGED OR FRACTURED.
Probable cause
A HARD LANDING CAUSED BY THE PILOT NOT BEING ABLE TO JUDGE HIS ALTITUDE ABOVE OR HIS CLOSURE RATE TO TERRAIN BECAUSE OF HIGH VEGETATION IN THE AREA AVAILABLE FOR A FORCED LANDING. AN ENGINE FAULURE CAUSED BY MATERIAL FAILURE OF THE COMPRESSOR SECTION IS A CONTRIBUTING CAUSE OF THE ACCIDENT.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI89LA191
- Event ID
- 20001213X29327
- Case number
- CHI89LA191
- 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: c28df0751a835436c646bf364c60be463d7b4761a62a2c28a959fde695503cfc; retrieved 2026-09-23T07:08:55.036Z.