MIA89LA165 · Bell 47G-3B-1
Valley Air Bell 47G-3B-1 · Accident: airframe, component or system failure en route
Event
- NTSB case
- MIA89LA165
- 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 47G-3B-1
- Aircraft type
- Bell 47
- 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
- N53SP
- Operator
- Valley Air
- 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
- 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
- Airframe, component or system failure
- Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
- Tree(s)
- 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
- Rotor drive system, tail rotor drive shaft › Bent
- Rotor drive system, tail rotor drive shaft › Disconnected
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
THE PLT RPRTD THAT WHILE DEPG ON A SPRAYING OPN, THE HELICOPTER YAWED TO THE RGT & LEFT PEDAL APPLICATION WOULD NOT CORRECT THE YAW. HE THEN PERFORMED AN AUTOROTATIVE LANDING, SUBSEQUENTLY PULLING THE COLLECTIVE TO CUSHION IMPACT WITH TREES. A POST-ACDNT EXAM OF THE HELICOPTER REVEALED THE TAIL ROTOR DRIVE SHAFT HAD BECOME BENT BETWEEN THE #1 & #2 BEARINGS, ALLOWING THE FWD SHAFT TO PULL FROM THE COUPLING.
Probable cause
THE TAIL ROTOR DRIVE SYSTEM BECAME DISCONNECTED DUE TO A BENT TAIL ROTOR DRIVE SHAFT. THE TREES CONTRIBUTED TO THE HELICOPTER DAMAGE.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record MIA89LA165
- Event ID
- 20001213X28388
- Case number
- MIA89LA165
- 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: d861c9cc523e03c7ea5e5467eaa05bdf2573837e7234f3be9813db61edc619c6; retrieved 2026-09-22T00:12:27.865Z.