# NTSB NYC82DA097: Bell 47G-2, N911X, Brookville, NY, May 15, 1982

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Final report
- Date: May 15, 1982, 16:15 local (20:15 UTC)
- Place: Brookville, NY
- Coordinates: 40.749565, -73.580474 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=40.7496&lon=-73.5805&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report May 15, 1983
- Report: Approved by Office Director
- NTSB case key (mKey): 70045
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC82DA097
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/70045/pdf
- Page: https://openairdocs.org/ntsb/NYC82DA097

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Loss of engine power(partial) - mech failure/malf, cruise - normal
  - engine assembly,valve,intake - failure,partial (cause)
  - precautionary landing - initiated, pilot in command
- Loss of engine power(total) - mech failure/malf, approach
  - engine assembly,valve,intake - leak (cause)
- Forced landing, landing
  - autorotation - performed, pilot in command (contributing factor)
- Nose over, landing - flare/touchdown
  - terrain condition - soft (contributing factor)

## Analysis

WHILE RETURNING TO THE HELIPORT, THE PILOT NOTICED A DECAY IN THE ENGINE AND ROTOR RPM'S. HE ELECTED TO MAKE A PRECAUTIONARY LANDING IN A PLOWED FIELD. DURING LANDING, THE MANIFOLD PRESSURE WENT TO THE RED LINE WHILE THE RPM DECAYED. THE HELICOPTER TOUCHED DOWN SOFTLY, BUT WITH ABOUT 10 MPH FORWARD SPEED. IT ROLLED FORWARD AND TO THE RIGHT WHEN THE SKIDS DUG INTO THE SOFT GROUND. AN INVESTIGATION REVEALED THAT THE NO. 6 CYLINDER HAD A LOW COMPRESSION READINGOF 5/80 WITH BLOW-BY EVIDENT INTO THE INTAKE SYSTEM. WHEN THE CYLINDER WAS REMOVED, THE INTAKE VALVE WAS FOUND NOT TO BE SEATING PROPERLY. NO OTHER MALFUNCTION OR DEFECT OF THE ENGINE OR ENGINE CONTROLS WAS NOTED.

## Aircraft

- Registration: [N911X](https://openairdocs.org/deregistered/N911X-2014-12-05), registration cancelled 2014-12-05, S/N 2511, built 1959 (OpenAirDocs)
- Reported make and model: BELL 47G-2
- Registry model: [Bell 47G-2](https://openairdocs.org/model/bell-47g-2) (registry code 1181008) (OpenAirDocs)
- Registry engine: [Lycoming 0-435](https://openairdocs.org/engine/lycoming-0-435) (registry code 41516, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: 2511
- Airframe hours: 2642
- Engines: LYCOMING VIO-435-A1E 240 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Island Helicopter, Inc.
- Registered owner: Island Helicopter, Inc.
- Departed: 4N6, GARDEN CITY, NY
- Destination: 4N6, GARDEN CITY, NY

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 26; commercial; medical: class 2, valid medical--w/ waivers/lim; flight hours: 192 total, 42 in this make and model, 106 as pilot in command, 6 in the last 90 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 50 statute miles
- Temperature: 172 °F

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19820515016109A](https://openairdocs.org/incident/19820515016109A), May 15, 1982: Bell 47G2, Brookville, NY, Substantial damage. Engine lost power and pilot attempted precautionary landing. Helicopter turned over on soft ground.

## Other investigations on N911X (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 NYC81FHM04](https://openairdocs.org/ntsb/NYC81FHM04), Apr 16, 1981: Bell 47G-2 (N911X), Wingdale, NY, substantial damage

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.

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