# NTSB LAX84LA108: Bell 47G, N4475, El Cajon, CA, December 21, 1983

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: December 21, 1983, 13:25 local (21:25 UTC)
- Place: El Cajon, CA
- Coordinates: 32.789672, -116.960388 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=32.7897&lon=-116.9604&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 24122
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX84LA108
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/24122/pdf
- Page: https://openairdocs.org/ntsb/LAX84LA108

## Sequence of events

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

- Hard landing, landing - flare/touchdown
  - emergency procedure - simulated, pilot in command
  - autorotation - performed, pilot in command
  - level off - not maintained, pilot in command (cause)

## Analysis

DURING A DEMONSTRATION TO SHOW HIS STUDENT HOW TO AUTOROTATE FM A 2 FT HEIGHT AGL THE INSTRUCTOR REDUCED PWR AND INADVERTENTLY APPLIED FWD CYCLIC. THE FRONT PORTION OF THE SKIDS HIT THE GD FOLLOWED BY THE MAIN ROTOR BLADES. HELICOPTER THEN ROCKED BACKWARDS, THE REAR PORTION OF THE SKIDS IMPACTED THE GD AND THE MAIN ROTOR BLADES SLICED THROUGH THE TAILBOOM.

## Aircraft

- Registration: [N4475](https://openairdocs.org/deregistered/N4475-2012-11-29), registration cancelled 2012-11-29, S/N 5503, built 1969 (OpenAirDocs)
- Reported make and model: BELL 47G
- Registry model: [Bell 47G](https://openairdocs.org/model/bell-47g) (registry code 1181002) (OpenAirDocs)
- Registry engine: [Franklin 6V4 series](https://openairdocs.org/engine/franklin-6v4-series) (registry code 27033, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: 5503
- Airframe hours: 4124
- Engines: FRANKLIN 6V4-200-C32 200 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Registered owner: Kenneth J. Tooker
- Airworthiness certificate: Standard, Normal
- Last inspection: Unknown, December 10, 1983, 11 hours before
- Airport: SEE, Gillespie Fld

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 28; commercial, flight instructor; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: right; flight hours: 2,811 total, 411 in this make and model, 2,591 as pilot in command, 200 in the last 90 days, 60 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 220° at 10 knots
- Visibility: 25 statute miles
- Lowest ceiling: 4,000 ft broken
- Temperature: 61 °F
- Altimeter: 30.00 inHg
- Observed at: SEE

## 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 19831221062989A](https://openairdocs.org/incident/19831221062989A), Dec 21, 1983: Bell 47G, El Cajon, CA, Substantial damage. Instructor incorrectly used forward cyclic on practice hover autorotation. Helicopter entered dynamic roll condition

## Other investigations on N4475 (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 LAX78FUA13](https://openairdocs.org/ntsb/LAX78FUA13), Mar 25, 1978: Bell 47G (N4475), Torrance, CA, 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.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.