# NTSB LAX88LA080: Bell 47D1, N175K, Fontana, CA, January 3, 1988

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: January 3, 1988, 11:25 local (19:25 UTC)
- Place: Fontana, CA
- Coordinates: 34.08039, -117.459274 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=34.0804&lon=-117.4593&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report April 24, 1990
- Report: Approved by Office Director
- NTSB case key (mKey): 25931
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX88LA080
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/25931/pdf
- Page: https://openairdocs.org/ntsb/LAX88LA080

## Probable cause

NONE SUBMITTED

## Sequence of events

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

- Airframe/component/system failure/malfunction, cruise - normal
  - rotor system,tail rotor blade - separation (contributing factor)
  - rotor system,tail rotor hub - fatigue (cause)
- Forced landing, descent - emergency
  - directional control - not maintained, pilot in command (contributing factor)
  - lack of total experience in type of aircraft, pilot in command (contributing factor)
- In flight collision with terrain/water, descent - uncontrolled
  - terrain condition - rough/uneven (contributing factor)

## Analysis

DURING A SOLO INSTRUCTIONAL FLIGHT, THE PLT REPORTED THAT HE HEARD A LOUD BANG. THE ACFT BEGAN AN UNCONTROLLED SPINNING DESCENT TO THE RIGHT AND COLLIDED WITH THE TERRAIN. A TAIL ROTOR BLADE WAS FOUND TO HAVE SEPARATED FROM THE TAIL ROTOR. A METALLURGICAL EXAMINATION OF THE TAIL ROTOR YOKE REVEALED THAT THE YOKE FAILED DUE TO HIGH CYCLE FATIGUE.

## Aircraft

- Registration: N175K (not matched to a registry record)
- Reported make and model: BELL 47D1
- Category: Helicopter
- Serial number: 56
- Airframe hours: 8239
- Engines: FRANKLIN 6V335-A 210 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Registered owner: Lonnie Reid
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, October 16, 1987, 72 hours before
- Departed: CNO, CHINO, CA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 42; student; medical: class 3, valid medical--no waivers/lim.; seat: left; flight hours: 34 total, 34 in this make and model, 7 as pilot in command, 34 in the last 90 days, 26 in the last 30 days, 3 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 40 statute miles
- Lowest ceiling: 20,000 ft overcast
- Temperature: 61 °F, dew point 30 °F
- Altimeter: 30.00 inHg
- Observed at: SBD, 20 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 19880103000069A](https://openairdocs.org/incident/19880103000069A), Jan 3, 1988: Bell 47D1, Chino, CA, Substantial damage. Loud bang approaching airport. Went into a spin to ground impact. Lost a tail rotor blade due to a failed yoke.

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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