# NTSB LAX88DUG07: Bell 47G-5A, N4099G, Perris, CA, September 18, 1988

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Final report
- Date: September 18, 1988, 12:00 local (19:00 UTC)
- Place: Perris, CA
- Location: 33.7825° N, 117.2286° W: Placed by OpenAirDocs: center of Perris, CA, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=33.7825&lon=-117.2286&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report November 24, 1989
- Report: Approved by Office Director
- NTSB case key (mKey): 25721
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX88DUG07
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/25721/pdf
- Page: https://openairdocs.org/ntsb/LAX88DUG07

## Sequence of events

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

- Airframe/component/system failure/malfunction, takeoff
  - engine installation,suspension mounts - fatigue (cause)
  - rotor drive system,tail rotor drive shaft - disconnected (cause)
- Loss of control - in flight, takeoff
  - directional control - not possible
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

ON LIFTOFF, TAIL ROTOR CONTROL WAS LOST AND HELICOPTER SPUN WITH MAIN ROTOR STRIKING TERRAIN. INVESTIGATION REVEALED FATIGUE FAILURE OF ENGINE MOUNTING CAGE. THE ENG BASKET HAD FAILED AND ALLOWED THE T/R DRIVE SHAFT TO PULL OUT OF THE COUPLING. THE BASKET HAD 800 HRS FLT TIME AND WAS CRACKED AND CORRODED. DUE TO CLOSENESS OF A FUEL TRUCK THE PLT HAD LIMITED ROOM FOR MANEUVERING.

## Aircraft

- Registration: [N4099G](https://openairdocs.org/deregistered/N4099G-2017-04-04), registration cancelled 2017-04-04, S/N 7909, built 1968 (OpenAirDocs)
- Reported make and model: BELL 47G-5A
- Registry model: [Bell 47G-5A](https://openairdocs.org/model/bell-47g-5a) (registry code 1181034) (OpenAirDocs)
- Registry engine: [Lycoming VO-435 series](https://openairdocs.org/engine/lycoming-vo-435-series) (registry code 41525, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: 7909
- Airframe hours: 11410
- Engines: LYCOMING VO-435-B1A 260 horsepower reciprocating
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Registered owner: Aerohead Helicopters, Inc.
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: 100 hour, October 25, 1987, 26 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 42; commercial, flight instructor; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 10,452 total, 3,000 in this make and model, 10,000 as pilot in command, 120 in the last 90 days, 5 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 30 statute miles
- Lowest ceiling: none
- Temperature: 84 °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 19880918039149A](https://openairdocs.org/incident/19880918039149A), Sep 18, 1988: Bell 47G5A, Perris, CA, Substantial damage. Lost tail rotor control on liftoff. Rotor hit ground along side of loader. Engine basket fatigue fractured.

## Other investigations on N4099G (2)

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 LAX84LA424](https://openairdocs.org/ntsb/LAX84LA424), Aug 1, 1984: Bell 47G-5A (N4099G), Winterhaven, CA, substantial damage
- [NTSB LAX76DUJ29](https://openairdocs.org/ntsb/LAX76DUJ29), Sep 8, 1975: Bell 47G-5 (N4099G), Chandler, AZ, 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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