# NTSB LAX88LA059: Hughes 369HS, N77DJ, Lihue, Kauai, HI, November 26, 1987

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: November 26, 1987, 08:10 local (18:10 UTC)
- Place: Lihue, Kauai, HI
- Coordinates: 21.969779, -159.350997 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=21.9698&lon=-159.3510&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 3 serious
- Status: Completed, report November 15, 1989
- Report: Approved by Office Director
- NTSB case key (mKey): 25916
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX88LA059
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/25916/pdf
- Page: https://openairdocs.org/ntsb/LAX88LA059

## Probable cause

PILOT FAILURE TO MAINTAIN ADEQUATE MAIN ROTOR RPM.

## Sequence of events

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

- Loss of control - in flight, descent - normal
  - rotor rpm - not maintained, pilot in command (cause)
  - rotorcraft flight controls - improper use of, pilot in command (cause)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

THE PILOT, WHO WAS ALSO A CERTIFICATED AIRFRAME & POWERPLANT MECH, RECENTLY CHANGED THE TAILBOOM ASSY. AT THE TIME OF THE ACCIDENT HE WAS CONDUCTING A MAINTENANCE TEST FLIGHT. THE PILOT EXECUTED ONE AUTOROTATION WITH A POWER RECOVERY. THE PLT REENTERED THE TRAFFIC PATTERN. GND WITNESSES REPTD THAT WHEN THE HELICOPTER ENTERED THE BASE LEG THEY HEARD AN EXPLOSIVE SOUND FOLLOWED BY THE TAILBOOM ASSY SEPARATING FROM THE HELICOPTER. THE WRECKAGE EXAM DSCLSD THE MAIN ROTOR BLADE STRUCK THE TAILBOOM. THE TAIL ROTOR BLADES WENT OUT OF TRACK AND STRUCK THE VERTICAL FINS, SEPARATING THE UPPER VERTICAL FIN. NO EVIDENCE OF ANY PREEXISTING MALFUNCTIONS WAS FOUND. THE MAIN ROTOR BLADES EXHIBITED LOW ROTOR RPM DAMAGE.

## Aircraft

- Registration: [N77DJ](https://openairdocs.org/deregistered/N77DJ-2013-05-09), registration cancelled 2013-05-09, S/N 0683, built 1974 (OpenAirDocs)
- Reported make and model: HUGHES 369HS
- Registry model: [Hughes 369HS](https://openairdocs.org/model/hughes-369hs) (registry code 4470728) (OpenAirDocs)
- Registry engine: [Allison 250 SER 400HP](https://openairdocs.org/engine/allison-250-ser-400hp) (registry code 03013, turbo-shaft) (OpenAirDocs)
- Category: Helicopter
- Serial number: 1240683S
- Airframe hours: 3932
- Engines: ALLISON 250-C20B 375 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Part 91
- Operator: Kauai Helicopters
- Registered owner: Leaveil De Gree
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, November 19, 1987, 14 hours before
- Airport: LIH, Lihue, runway 3, 6,000 × 100 ft, macadam

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 42; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 5,000 total, 1,215 in this make and model, 5,000 as pilot in command, 100 in the last 90 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 80° at 18 knots
- Visibility: 14 statute miles
- Lowest ceiling: none
- Temperature: 77 °F, dew point 68 °F
- Altimeter: 30.00 inHg
- Observed at: LIH

## 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 19871126067269A](https://openairdocs.org/incident/19871126067269A), Nov 26, 1987: Hughes 369HS, Lihue, HI, Destroyed. Tail rotor assembly separated in a test flight after installation during autorotation. Damage shows main rotor hit.

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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