# NTSB MIA88FA257: Hughes 500, N3766Z, Riviera Beach, FL, August 19, 1988

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Field investigation · Final report
- Date: August 19, 1988, 07:10 local (11:10 UTC)
- Place: Riviera Beach, FL
- Coordinates: 26.78075, -80.059852 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=26.7808&lon=-80.0599&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious, 1 minor
- Status: Completed, report November 7, 1989
- Report: Approved by Office Director
- NTSB case key (mKey): 32037
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MIA88FA257
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/32037/pdf
- Page: https://openairdocs.org/ntsb/MIA88FA257

## Sequence of events

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

- In flight collision with object, cruise - normal
  - object - bird(s) (cause)
  - rotor system,tail rotor blade - separation
  - rotor drive system,tail rotor gearbox(90 deg) - separation
- Forced landing, descent - emergency
  - autorotation - performed, pilot in command
- In flight collision with object, descent - emergency
  - object - tree(s) (contributing factor)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

THE TRAFFIC WATCH HELICOPTER WAS CRUISING NORTHBOUND ALONG THE INTERSTATE AT 450 FT AGL & 85 KTS AIRSPEED. A GRINDING NOISE WAS HEARD & THE TAIL ROTOR SEPARATED FROM THE ACFT. THE ACFT BEGAN AN UNCOMMANDED RIGHT TURN WHICH WAS ARRESTED IN ABOUT 1/4 TURN. THE PLT ATTEMPTED TO AUTOROTATE INTO AN OPEN FIELD JUST EAST OF THE HWY, BUT STRUCK A 25 FT TREE AT THE EDGE & CRASHED. AN EXAM REVEALED THE TAIL ROTOR GEAR BOX HOUSING, P/N 369A5400-607, HAD FAILED. A PORTION OF THE HOUSING, DRIVEN GEAR, TAIL ROTOR BLADES & RELATED COMPONENTS SEPARATED FROM THE ACFT IN FLT. THE MISSING PARTS SANK IN A LAKE ABOUT 1/2 MI FROM THE CRASH SITE & WERE NOT RECOVERED. THE REMAINING SECTION OF THE BOX WAS EXAMINED BY NTSB LAB & FAILURE WAS DUE TO OVERLOAD WITH NO EVIDENCE OF FATIGUE OR CORROSION. A WITNESS SAW 2 OBJECTS FALL FROM THE HELICOPTER. ONE OBJECT WAS WHITE AND LOOKED LIKE A BIRD, PROBABLY A SEAGULL. THE OTHER OBJECT LOOKED LIKE A STICK OR A 2X4 PIECE OF WOOD.

## Aircraft

- Registration: [N3766Z](https://openairdocs.org/aircraft/N3766Z), registered now, S/N 440588S, built 1974 (OpenAirDocs)
- Reported make and model: HUGHES 500
- Registry model: [Hughes 369HS](https://openairdocs.org/model/hughes-369hs) (registry code 4470728) (OpenAirDocs)
- Registry engine: [Allison 250 SER 250HP](https://openairdocs.org/engine/allison-250-ser-250hp) (registry code 03002, turbo-shaft) (OpenAirDocs)
- Category: Helicopter
- Serial number: 440588S
- Airframe hours: 4635
- Engines: Allison 250-C20 420 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Aerial observation, Part 91
- Operator: Trafficopters, Inc.
- Registered owner: Trafficopters, Inc
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, August 1, 1988, 40 hours before
- Departed: PBI, WEST PALM BEACH, FL

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 40; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 6,350 total, 1,082 in this make and model, 6,280 as pilot in command, 58 in the last 90 days, 27 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 120° at 6 knots
- Visibility: 7 statute miles
- Lowest ceiling: none
- Temperature: 81 °F, dew point 73 °F
- Altimeter: 29.00 inHg
- Observed at: PBI, 6 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 19880819034249A](https://openairdocs.org/incident/19880819034249A), Aug 19, 1988: Hughes 369HS, Riviera Beach, FL, Substantial damage. Gear box fractured from instant overload and tail rotor assembly departed aircraft. Crashed and rolled over landing

## Other investigations on N3766Z (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 ATL81FA118](https://openairdocs.org/ntsb/ATL81FA118), Sep 30, 1981: Hughes 369A (N3766Z), Atlanta, GA, 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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