Novictor Aviation Robinson R44 II accident
Robinson R44 II · Accident: system/component malfunction/failure (non-power) before flight
Event
- NTSB case
- ANC24LA077
- 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
- Charter & commuter
- 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 R44 II
- Aircraft type
- Robinson R44
- 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
- N740RH
- Operator
- Novictor Aviation
- Onboard fatalities
- Unknown
- Route
- From not recordedTo not recorded
- Aircraft age
- About 6 years (built 2018)
- 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 135: Air Taxi & Commuter
- 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
- Prior to flight
- Defining eventThe 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
- System/component malfunction/failure (non-power)
- 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
- Aircraft › Aircraft propeller/rotor
- Personnel issues › Task performance
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 reported that, before boarding passengers, she started the engine, engaged the clutch and, as the main rotor system began to engage, she felt and saw the left pedal deflect full forward without any control input. The pilot immediately shut down the engine, stopped the rotors, and exited the helicopter to inspect the tail rotor assembly. The tail rotor push-pull tube was found bent and severed aft of the tail rotor gear box, near the bell crank assembly. A postaccident examination revealed a bolt missing from the flex plate assembly, just forward of the tail rotor gearbox. The bolt was found in the tailboom just below the flex plate assembly and exhibited significant circumferential wear marks. A second bolt from the flex plate assembly exhibited similar wear; the two other bolts in the assembly exhibited no wear and were firmly torqued to the flex plate assembly. Black dust was observed on the flex plate and associated hardware, indicative of fretting. The helicopter went through a major overhaul in May of 2024, at which time the tail rotor drive shaft, aft flex plate assembly, and tail rotor push-pull tube were installed. Since May of 2024 the accident helicopter had flown about 338 hours. The most recent 100-hour inspection was completed on August 1, 2024, by the operator. The 100-hour inspection requires the operator to inspect the tail rotor flex plate assembly. A review of the airframe maintenance logbooks showed evidence of compliance with the helicopter manufacturer’s 100-hour inspection to include the flex plate assembly. The circumferential wear and black dust present during the postaccident examination indicate that the bolts were likely loose during the 100-hour inspection; however, no evidence of fretting or looseness was documented.
It is likely that, over time, two of the bolts in the flex plate assembly became loose during operation because they were not properly torqued during installation.
Probable cause
A failure of the flex plate yoke flange assembly due to incorrectly torqued bolts. Contributing was the maintenance personnel’s inadequate inspection of the tail rotor flex plate assembly.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ANC24LA077
- Event ID
- 20240819194946
- Case number
- ANC24LA077
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
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: local date, investigation status, coordinates, cause areas. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2024-08-19.
- API snapshot SHA-256: e57132f27b4685b1dff8fe22fce169bff402c4c90427b6b1c98d958c688ce104; retrieved 2026-09-16T19:10:47.060Z.