LAX03LA123 · Robinson R-44 II
Robinson R-44 II · Accident: airframe, component or system failure en route
From Tucson International Airport (KTUS) to St. Louis Lambert International Airport (KSTL)
Event
- NTSB case
- LAX03LA123
- 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
- Unknown
- 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
Robinson R-44 II
- Aircraft type
- Robinson R-44
- 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
- N233TR
- Operator
- Thomas Hughes
- Onboard fatalities
- Unknown
- Route
- From Tucson International Airport (KTUS), Tucson, AZTo St. Louis Lambert International Airport (KSTL), St Louis, MO
- 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
- Airframe, component or system 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
- Electrical system, drive/belt › Failure
- Rotor drive system, main rotor drive belt › Failure
- Rotor drive system, main rotor drive belt › Foreign object damage
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The pilot executed an emergency landing after experiencing a drive belt failure. During cruise flight, the alternator light illuminated and the ammeter showed a drop. The pilot turned off all nonessential electrical equipment. The pilot heard a "thump," which was followed by the smell of burnt rubber. About 15 seconds later, the clutch light illuminated and the pilot heard a "thud." The pilot lowered the collective and both lights continued to illuminate. The pilot then entered an autorotation and pulled the clutch circuit breaker. As the helicopter settled from the flare, it contacted a "clump" of dirt. The helicopter tipped forward, which bent the forward portion of the skids, and resulted in the main rotor striking the tail boom. No preimpact anomalies with either the airframe or engine were discovered. The main rotor drive belts were found in the drive compartment in a shredded condition. The alternator belt was not recovered.
I
Probable cause
The failure of the alternator belt which resulted in the failure of the main drive belt.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record LAX03LA123
- Event ID
- 20030408X00461
- Case number
- LAX03LA123
- 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, coordinates. 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: 6512c236a7dfffd433151e589dc9f28082adad35eb05ce9e3d99196af158a731; retrieved 2026-09-22T09:26:47.869Z.