MIA98LA254 · Bell 47-D1
Sky Tractor Bell 47-D1 · Accident: airframe, component or system failure en route
From University Oxford Airport (UOX) to 0M6 · Batesville, MS
Event
- NTSB case
- MIA98LA254
- 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 47-D1
- 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
- N755E
- Operator
- Sky Tractor
- Onboard fatalities
- Unknown
- Route
- From University Oxford Airport (UOX)To 0M6 · Batesville, MS
- 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
- Pilot in command › Unsuitable terrain or takeoff/landing/taxi area, encountered
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
No discrepancies were found during the preflight. Shortly after takeoff, about 400-500 feet agl, the pilot felt a short duration minor vibration in the cyclic. The vibration increased in intensity but reduced when collective was lowered. He flew towards a clearing but with obstructions in the flight path, he intentionally collided with trees. Weeks earlier, the pilot noted a crack in the laminate on the top of the 'blue' main rotor blade which progressed thru to the bottom of the blade. Two mechanics inspected the blade; one determined that water was present, the other reported that the crack was only in the laminant. A mechanic repaired the crack by applying a two-part adhesive externally to cover the crack. According to the helicopter maintenance and overhaul instructions manual, there was no mention that epoxy type material can be applied to the surfaces of the fiberglass cloth that was damaged. Post accident examination of the flight controls revealed no evidence of preimpact failure or malfunction. Examination of the blue main rotor blade revealed a segment of blade missing but no determination could be made as to the reason for the separation.
Probable cause
The pilot's failure to maintain directional control due to vibration from the main rotor blade for undetermined reasons. A related finding was the improper repair of a crack in the laminant of the blue main rotor blade by other maintenance personnel.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record MIA98LA254
- Event ID
- 20001211X11135
- Case number
- MIA98LA254
- 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: c9b11f0e241afc0c78ee20ad58f9536df7796672bc19ecfa4daaa2b3dcb9f539; retrieved 2026-09-21T20:41:13.632Z.