# Incident 20180731024189I: Robinson Helicopter Company R44 II, Ruby, AK, July 31, 2018

- Type: FAA incident report (Accident/Incident Data System), as reported
- Date: July 31, 2018, 10:26 local time
- Place: Ruby, AK
- Damage: No damage
- Phase of flight: Cruise/Level Flight
- Operating rules: Air taxi and commuter (Part 135)
- Operator: UPXC
- Location: 64.7233° N, 155.5005° W: Placed by OpenAirDocs: center of Ruby, AK, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=64.7233&lon=-155.5005&mi=10
- Aircraft: N74381, registered now (https://openairdocs.org/aircraft/N74381) (OpenAirDocs)
- Registry model: Robinson Helicopter R44 II (registry code 7640122, https://openairdocs.org/model/robinson-helicopter-r44-ii) (OpenAirDocs)
- Registry engine: Lycoming IO-540 series (registry code 41530, https://openairdocs.org/engine/lycoming-io-540-series) (OpenAirDocs)
- Reported make and model: ROBINSON HELICOPTER COMPANY R44 II
- Reported engine: LYCOMING IO-540 SER
- People aboard: 3
- Fatal injuries: 0
- Other injuries: 0
- Pilot certificates: Commercial pilot, flight instructor
- Pilot flight hours: 1,678 total, 1,534 in this make and model, 137 in the last 90 days
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/20180731024189I

## Narrative

As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^.

WHILE IN CRUISE FLIGHT AT ~500 AGL, ON RETURN TRIP TO BASE AFTER ABOUT 1.6 HRS OF FLIGHT, PILOT HEARD FLUCTUATION IN ENGINE AND ACTIVATION OF LOW ROTOR HORN.  HE TRIED ONCE TO ENSURE THROTTLE WAS FULL OPEN AND REDUCED COLLECTIVE BUT HORN REMAINED SO HE ENTERED FULL AUTOROTATIVE DESCENT AND LANDED IN SWAMPY GROUND WITH NO DAMAGE OR INJURIES.   AFTER LANDING, ENGINE WAS STILL AT IDLE, SO SHUTDOWN INITIATED.  AIRCRAFT SANK TO BELLY IN SOFT GROUND SO RESTART AND RUNUP WAS NOT ATTEMPTED UNTIL AIRCRAFT RAISED AND PLACED ON SHORING.  D.O.M. ARRIVED AND RAN UP AIRCRAFT WITH NO FAULTS NOTED.  A/C RUN AT FULL POWER AND HOVERED IN PLACE FOR 5 HOURS WITH NO INTERRUPTIONS OR ANOMALIES.  AIRCRAFT RELEASED FOR RECOVERY TO HOME STATION.  AFTER ANOTHER 5 HOUR FLIGHT HOME WITH NO ANOMALIES. SERVO, MANIFOLD, FUEL SYSTEM INSPECTED WITH NO FAULTS OR CONTAMINATION IN ANY PART.  DISCUSSION WITH PILOT SHOWED POSSIBILITY THAT LOW ROTOR HORN WAS SINGLE INDICATION AND THAT ENGINE STILL FULLY FUNCTIONING, BUT DUE TO PROXIMITY TO GROUND AND LACK OF TIME OR ALTITUDE TO TROUBLESHOOT, HE HAD INITIATED AUTOROTATION AUTOMATICALLY.    MAINTENANCE STATED SECOND SET OF POINTS IN RIGHT MAG THAT PROVIDE LOW ROTOR SIGNAL MAY HAVE BEEN INTERUPTED CAUSING ERRONEOUS LOW ROTOR INDICATION WHILE NONE WAS PRESENT.  TEAR DOWN AND ISPECTION OF FUEL AND MAG SYSTEMS HIGLIGHTED NO READILY APPARENT FAULTS.   FILTERS INSPECTED AGAIN, VALVE GUIDE CHECK COMPLETED, MAGS BENCH TESTED WITH NO FAULTS FOUND.   A SLIGHT BINDING CONDITION NOTED IN FUEL SERVO THROTTLE LEVER JUST ABOVE MIDRANGE.  SERVO REPLACED OUT OF ABUNDANCE OF CAUTION AND SUSPECT UNIT SENT TO MANUFACTURER FOR TEARDOWN ANALYSIS.  AIRCRAFT RETURNED TO SERVICE.

## Other reports on N74381 (1)

Matched to the same aircraft by N-number and date.

- [Incident 20200705009209I](https://openairdocs.org/incident/20200705009209I), Jul 5, 2020: Robinson Helicopter Company R44 II (N74381), Cold Foot, AK, Minor damage. Aircraft was in a hovering toe in landing, at power. Passengers were preparing to off load when a spruce tree feel into the main rotor. Pilot accomplished a…

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record.

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