# Accident 19981214046419A: Bell 47G5, Essex Junction, VT, December 14, 1998

- Type: FAA accident report (Accident/Incident Data System), as reported
- Date: December 14, 1998, 16:44 local time
- Place: Essex Junction, VT
- Damage: Destroyed
- Phase of flight: Autorot Descent (Rotorcraft)
- Operating rules: General operating rules (Part 91)
- Location: 44.4903° N, 73.1141° W: Placed by OpenAirDocs: center of Essex Junction, VT, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=44.4903&lon=-73.1141&mi=10
- Aircraft: N8103J, registered now (https://openairdocs.org/aircraft/N8103J) (OpenAirDocs)
- Registry model: Bell 47G-5 (registry code 1181032, https://openairdocs.org/model/bell-47g-5) (OpenAirDocs)
- Registry engine: Lycoming VO-435 series (registry code 41525, https://openairdocs.org/engine/lycoming-vo-435-series) (OpenAirDocs)
- Reported make and model: BELL 47G5
- Reported engine: LYC VO435B1A
- Fatal injuries: 0
- Pilot flight hours: 490 total, 139 in this make and model, 6 in the last 90 days
- NTSB investigation: [NTSB IAD99LA024](https://openairdocs.org/ntsb/IAD99LA024) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/19981214046419A

## Narrative

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

(.4)THE PILOT AND MECHANIC DEPARTED ON A MAINTENANCE TEST FLIGHT AFTER COMPLETING THE INSTALLATION OF AN OVERHAULED ENGINE. THEY PERFORMED GROUND ENGINE RUNS AND TWO SHORT LEGS OF THE TEST FLIGHT.  AFTER EACH LEG, THE HELICOPTER WAS SHUT DOWN AND THE ENGINE WAS CHECKED FOR LEAKS.  THE PILOT DEPARTED ON THE THIRD LEG AFTER OFFICIAL SUNSET, AND AFTER CLIMBING TO APPROXIMATELY 1,700 FEET, THE PILOT CLOSED THE THROTTLE, THEN ENTERED AUTOROTATION.  THE MECHANIC SAID THE ENGINE AND ROTOR RPM DECAYED SIMULTANEOUSLY AND THEN THE ENGINE STOPPED RUNNING.  DURING DESCENT, THE PILOT ATTEMPTED TO RESTART THE ENGINE WITHOUT SUCCESS.  THE AUTOROTATION WAS TERMINATED WITH A HARD LANDING. EXAMINATION OF THE ENGINE REVEALED NO ANOMALIES AND IT RAN TO RATED POWER IN A TEST CELL.  WHILE OPERATING AT FULL RPM, THE THROTTLE WAS MOVED RAPIDLY TO THE FLIGHT IDLE POSITION.  THE ENGINE EXHIBITED A SMOOTH REDUCTION IN RPM TO THE IDLE POWER SETTING WITH NO INTERRUPTION. AN FAA HELICOPTER HANDBOOK STATED TO BEGIN AN AUTOROTATION, THE COLLECTIVE SHOULD BE PLACED FULL DOWN MAINTAIN CRUISE RPM WITH THE THROTTLE.  THEN DECREASE THE THROTTLE AND ADJUST IT TO KEEP THE ENGINE RPM 'WELL ABOVE NORMAL IDLING SPEED.'    (-23) AIRCRAFT LEFT LAMELL LUMBER YARD AFTER APPROX. 30 MINS OF GRND RUNS TO CHECK OVER ENGINE R&R. DEPARTED TO NORTH AND MADE A LANDING IN PLOWED FIELD OFF OF RT 128 (BEHIND HALLETT'S FARM) AND PILOT & MECH PASSENGER CKD OVER INSTALLATION FOR LEAKS.  THEN DEPARTED VERTICALLY RACING NORTH TO APPROX 1500' AGL.  PILOT INTENDED TO DO AUTO ROTATION WITH POWER RECOVERY.  ON SHUTTING THROTTLE, ENGINE QUIT- UNABLE TO RESTART- UNSUCCESSFUL AUTO-ROTATION ATTEMPT.

## The NTSB's investigation of this event (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB IAD99LA024](https://openairdocs.org/ntsb/IAD99LA024), Dec 14, 1998: Bell 47-G5 (N8103J), Essex Junction, VT, substantial damage. Probable cause: the pilot's improper entry into the autorotation, which resulted in the loss of power and a low rotor rpm condition. Also causal was the pilot's improper execution of the autorotation which resulted…

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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