ERA14LA311 · Robinson Helicopter Company R44 II
Robinson Helicopter Company R44 II · Accident: hard landing during autorotation
From John C Tune Airport (JWN) to Decatur Airport (DEC)
Event
- NTSB case
- ERA14LA311
- 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 Helicopter Company 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
- N544BS
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From John C Tune Airport (JWN), Nashville, TNTo Decatur Airport (DEC), Decatur, IL
- Aircraft age
- About 11 years (built 2003)
- 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
- Autorotation
- 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
- Hard landing
- 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 oper/perf/capability
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot took off from his departure airport on a cross-country helicopter flight. The pilot reported that, when the helicopter was about 1 mile north of the airport and near a group of high-powered transmission broadcast towers, the engine started running roughly and that he felt an uncommanded decrease in engine power and movement of the twist grip throttle. The pilot initiated an autorotation, and the helicopter landed hard, which resulted in substantial damage to the tailboom. Postaccident examination of the engine revealed no mechanical anomalies that could have precluded normal operation.
According to a flight instructor based at the departure airport, he had encountered a similar uncommanded decrease in engine power on multiple occasions while flying east of the same broadcast towers in the same make and model helicopter. During each encounter, the pilot felt the movement of the electronic governor through the throttle twist grip and was able to override the governor by advancing the throttle. Further, Federal Aviation Administration research revealed that high-power broadcast AM radio transmitters likely affect the governor circuit on this helicopter and can result in governor control that reduces the engine speed regardless of the pilot's power input. Thus, it is likely that radio frequency interference increased the engine speed signal frequency as the pilot flew the helicopter near the transmission towers. The governor controller then engaged the governor motor to decrease engine power, which the pilot perceived as a loss of power.
About 15 years before the accident, the manufacturer had issued a safety notice to address previous reports of radio interference. The safety notice stated that flying near broadcast towers may result in "erratic operation of the governor," which may cause the governor to roll the throttle to the idle or open position. The notice also instructed pilots to keep one hand on the collective and throttle and to refrain from flying near broadcast towers. The pilot reported that he was familiar with the safety notice but that he had not read it since he purchased the helicopter about 7 years before the accident. The pilot should have been able to recognize that the engine was still producing power and overridden the governor by moving the twist grip throttle, and he should have been able to maintain rotor rpm while executing the autorotation, which would have resulted in a softer landing; however, he did not do so.
Probable cause
The pilot’s failure to maintain rotor rpm during an autorotation after a perceived partial loss of power, which resulted in a hard landing. Contributing to the accident was radio frequency interference with the governor controller, which resulted in an uncommanded decrease in throttle and the perceived loss of engine power.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ERA14LA311
- Event ID
- 20140624X00629
- Case number
- ERA14LA311
- 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: 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: 5ab7a46ebab4b4d5475f377562bc05ba6a5ffa21d43f2ff48d4b1e660ac12e8a; retrieved 2026-09-16T00:27:01.863Z.