# NTSB LAX90LA186: Hughes 269A, N8793F, La Verne, CA, May 23, 1990

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: May 23, 1990, 09:20 local (16:20 UTC)
- Place: La Verne, CA
- Coordinates: 34.149288, -117.759544 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=34.1493&lon=-117.7595&mi=10
- Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 2 minor
- Status: Completed, report January 31, 1994
- Report: Approved by Office Director
- NTSB case key (mKey): 26812
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX90LA186
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/26812/pdf
- Page: https://openairdocs.org/ntsb/LAX90LA186

## Probable cause

GROUND RESONANCE DUE TO AN INADEQUATELY MAINTAINED STRUT.

## Sequence of events

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

- Roll over, taxi - aerial
  - landing gear,skid assembly - pressure too low (cause)
  - maintenance,service of aircraft/equipment - inadequate, company/operator management (cause)
  - maintenance,service of aircraft/equipment - inadequate, pilot in command (cause)

## Analysis

THE PILOT HAD BEEN ASKED BY THE OPERATOR TO FLY THE HELICOPTER PRIOR TO THE OPERATORS SIGNING A LEASEBACK AGREEMENT WITH THE REPORTED OWNER. THE INITIAL AIR TAXI TO A HELIPAD WAS ABORTED WHEN THE HELICOPTER BEGAN TO OSCILLATE DURING A GROUND RESONANCE EVENT.  PRIOR TO THIS ATTEMPT THE OLEO STRUTS APPEARED TO BE OF EQUAL EXTENSION. AFTER THE EVENT, THE OLEO STRUTS WERE LOW AND ONE WAS FLAT. ABOUT 18 DAYS LATER, AND AFTER THE PILOT HAD BEEN TOLD THAT THE STRUTS HAD BEEN TAKEN CARE OF AND THAT THE OWNER HAD BEEN FLYING THE HELICOPTER AFTER A PLANNED AIR TAXI TO A HELIPAD. THE HELICOPTER AGAIN EXPERIENCED A GROUND RESONANCE EVENT WITH SEVERE OSCILLATIONS TO THE POINT OF DESTRUCTION. THE PILOT SAID HE LOWERED THE COLLECTIVE AND DECREASED THE THROTTLE WHEN THE OSCILLATIONS BEGAN. ATTEMPTS TO OBTAIN THE MAINTENANCE RECORDS AND COMPONENTS OF THE HELICOPTER FOR TESTING WERE UNSUCCESSFUL.

## Aircraft

- Registration: N8793F (not matched to a registry record)
- Reported make and model: HUGHES 269A
- Category: Helicopter
- Serial number: 0125A
- Engines: LYCOMING IO-360 180 horsepower reciprocating
- Damage: Substantial damage
- Flight: Positioning, Part 91
- Operator: Randy Polous, doing business as Airborne Helicopters
- Registered owner: Sam Clemens
- Airworthiness certificate: Standard, Normal
- Last inspection: Unknown, January 2, 2000
- Departed: POC, LA VERNE, CA
- Airport: POC, Brackett Field

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 29; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 323 total, 126 in this make and model, 259 as pilot in command, 14 in the last 90 days, 8 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 64 °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 19900523022909A](https://openairdocs.org/incident/19900523022909A), May 23, 1990: Hughes 269A, La Verne, CA, Substantial damage. On lift off to aerial taxi ground resonance ensued. Lowered collective and power but helicopter self destructed.

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.