# NTSB LAX91LA390: Bell 47G-3B-2, N2618D, Chula Vista, CA, September 10, 1991

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: September 10, 1991, 16:45 local (23:45 UTC)
- Place: Chula Vista, CA
- Coordinates: 33.150405, -117.279594 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=33.1504&lon=-117.2796&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 2 minor
- Status: Completed, report May 3, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 27356
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX91LA390
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27356/pdf
- Page: https://openairdocs.org/ntsb/LAX91LA390

## Probable cause

THE PILOT'S FAILURE TO MAINTAIN THE PROPER AIRSPEED AND MISJUDGING THE LANDING FLARE ALTITUDE.  THE POWERPLANT FAILURE FOR AN UNDETERMINED REASON AND THE UNSUITABLE TERRAIN FOR THE FLOAT EQUIPPED HELICOPTER WERE FACTORS IN THE ACCIDENT.

## Sequence of events

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

- Loss of engine power, approach - vfr pattern - final approach
  - single engine aircraft
  - powerplant - undetermined (contributing factor)
- Forced landing, descent - emergency
  - autorotation - performed, pilot in command (contributing factor)
- Hard landing, descent - emergency
  - terrain condition - none suitable (contributing factor)
  - flare - improper, pilot in command (cause)
  - airspeed - excessive, pilot in command (cause)
  - altitude - misjudged, pilot in command (cause)

## Analysis

THE PILOT WAS CONDUCTING A MAINTENANCE TEST FLIGHT OVER LAND IN A HELICOPTER EQUIPPED WITH A FLOAT LANDING GEAR. HIS FIRST AUTOROTATION WAS TERMINATED WITH A POWER RECOVERY.  DURING HIS SECOND AUTOROTATION THE ENGINE FAILED. THE PILOT MISJUDGED HIS AUTOROTATIVE LANDING FLARE AND THE HELICOPTER TOUCHED DOWN WITH A FORWARD GROUND SPEED AND TUMBLED ALONG ITS GROUND PATH.

## Aircraft

- Registration: [N2618D](https://openairdocs.org/deregistered/N2618D-1994-03-10), registration cancelled 1994-03-10, S/N 6676 (OpenAirDocs)
- Reported make and model: Bell 47G-3B-2
- Registry model: [Bell 47G-3B-2](https://openairdocs.org/model/bell-47g-3b-2) (registry code 1181029) (OpenAirDocs)
- Category: Helicopter
- Serial number: 6676
- Airframe hours: 12811
- Engines: ALLISON 250-C20 318 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Business, Part 91
- Operator: K & L Helicopters
- Registered owner: K & L Helicopters
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, September 10, 1991, 2 hours before
- Departed: SEE, EL CAJON, CA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 40; flight instructor, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 2,514 total, 100 in this make and model, 2,283 as pilot in command, 17 in the last 90 days, 8 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 290° at 7 knots
- Visibility: 25 statute miles
- Lowest ceiling: none
- Temperature: 75 °F
- Altimeter: 29.00 inHg
- Observed at: SEE, 15 nm away

## 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 19910910038949A](https://openairdocs.org/incident/19910910038949A), Sep 10, 1991: Bell STC47, Chula Vista, CA, Substantial damage. On test for engine turbine conversion. Engine failed respond autorotation power recovery. Fuel control adjustments.

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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