MIA92LA111 · Bell UH-1B
Colony Services Bell UH-1B · Accident: partial loss of engine power (mechanical failure) while maneuvering
Event
- NTSB case
- MIA92LA111
- 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 UH-1B
- Aircraft type
- Bell UH-1
- 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
- N4028F
- Operator
- Colony Services
- Onboard fatalities
- Unknown
- Route
- From not recordedTo 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 137: Agricultural
- 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 · aerial application
- 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
- Pilot in command › Aircraft preflight, inadequate
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
THE PLT STATED THAT THE FLT PATH OF THE HELICOPTER WAS PERPENDICULAR TO POWER LINES THAT WERE AHEAD. THE FLIGHT CONTINUED AND HE FURTHER STATED THAT HE HEARD A LOUD EXPLOSION & THE ENG QUIT. HE PULLED THE COLLECTIVE CONTROL & CLEARED THE POWER LINES THEN LOWERED IT, & PRIOR TO IMPACT WITH THE GROUND, PULLED THE COLLECTIVE CONTROL TO CUSHION THE IMPACT. THE HELICOPTER LANDED HARD, BOUNCED, TOUCHED DOWN, ROLLED OVER ON THE LT SIDE, THEN NOSED OVER & CAME TO REST INVERTED. A SMALL FIRE WAS EXTINGUISHED BY SEVERAL INDIVIDUALS WHO RESPONDED TO THE ACCIDENT SITE. THE ENG WAS REMOVED & SENT TO THE MANUFACTURER'S FACILITY FOR EXAMINATION. EXAM OF THE ENG REVEALED THAT A MOUNTING BOSS ON THE AIR DIFFUSER FAILED DUE TO FATIGUE. THE LINE ATTACHED TO THE BOSS WAS THE INTERSTAGE BLEED AIR LINE. ALSO, A POWER TURBINE BLADE FAILED DUE TO FATIGUE. REVIEW OF THE ENG LOGBOOKS REVEALED THAT THIS ENG WAS REMOVED FROM ANOTHER HELICOPTER & INSTALLED IN THIS HELICOPTER 6 DAYS PRIOR TO THE ACCIDENT. THE ENG HAD ACCUMULATED ABOUT 10 HRS SINCE THEN & 703 HRS SINCE MAJOR OVERHAUL. ACCORDING TO THE ENG DAILY INSPECTION CHECKLIST, THE AIR DIFFUSER EXTERNAL VANE BRAZEMENTS SHOULD BE CHECKED FOR CRACKS.
Probable cause
IMPROPER PREFLIGHT BY THE PILOT-IN-COMMAND, IN HIS FAILURE TO IDENTIFY A CRACK IN A BRAZED AREA SURROUNDING AN ATTACH POINT ON THE AIR DIFFUSER. CONTRIBUTING TO THE ACCIDENT FOLLOWING THE LOSS OF ENGINE POWER WAS OBSTACLES THAT WERE AHEAD OF THE FLIGHT PATH.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record MIA92LA111
- Event ID
- 20001211X14485
- Case number
- MIA92LA111
- 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: 4d65f925a321a726c909e69895b44f5806f875eb1e0149e09183764d828531bb; retrieved 2026-09-21T15:02:36.638Z.