# NTSB LAX89LA063: Hughes 369E, N7733H, Hanalei, HI, December 12, 1988

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: December 12, 1988, 12:48 local (22:48 UTC)
- Place: Hanalei, HI
- Coordinates: 22.200838, -159.500839 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=22.2008&lon=-159.5008&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 5 uninjured
- Status: Completed, report January 4, 1990
- Report: Approved by Office Director
- NTSB case key (mKey): 26308
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX89LA063
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/26308/pdf
- Page: https://openairdocs.org/ntsb/LAX89LA063

## Sequence of events

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

- Loss of engine power(partial) - mech failure/malf, maneuvering - turn to reverse direction
  - turboshaft engine,gas generator turbine - failure,total (cause)
  - turboshaft engine - overtemperature (cause)
  - exhaust system,probe - previous damage (contributing factor)
  - maintenance,service of aircraft/equipment - improper, other maintenance personnel (contributing factor)
- Forced landing, descent - emergency
- Nose over, landing - flare/touchdown
  - terrain condition - soft (contributing factor)

## Analysis

DURING A LOCAL SIGHTSEEING FLIGHT, THE PILOT REPORTED THAT HE HEARD A MUFFLED BANG AND SIMULTANEOUSLY THE ENGINE OUT WARNING LIGHTS AND AUDIO ALARM ACTIVATED. THE PILOT INITIATED A FORCED LANDING ON THE BEACH WHICH RESULTED IN THE HELICOPTER NOSING OVER. AN ENGINE EXAM REVEALED THAT THE GAS GENERATOR TURBINE HAD FAILED. THE EVIDENCE INDICATED THAT THE FAILURE WAS DUE TO CONSTANT TURBINE OVERTEMPERATURES. THE EXHAUST TEMPERATURE PROBE SYSTEM WAS TESTED AND SHOWED CONSISTENT READINGS 50 TO 100 DEGREES LOWER THAN THE ACTUAL TEMP. ADDITIONALLY, THE LIGHTOFF FUEL FLOW WAS EXCESSIVE DUE TO THE IMPROPER SETTING OF THE START/ACCELERATOR SCHEDULE ADJUSTER. MAINTENANCE RECORDS DID NOT INDICATE A RECENT EXHAUST TEMP CHECK.

## Aircraft

- Registration: N7733H (not matched to a registry record)
- Reported make and model: HUGHES 369E
- Category: Helicopter
- Serial number: 0168E
- Airframe hours: 5666
- Engines: ALLISON 250-C20B 375 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Business, Part 91
- Operator: Kauai Helicopter
- Registered owner: Kauai Helicopter
- Airworthiness certificate: Standard, Normal
- Last inspection: Unknown, November 18, 1988, 92 hours before
- Departed: LIHUE, HI
- Flight plan: Company VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 42; flight instructor, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 4,673 total, 693 in this make and model, 360 in the last 90 days, 115 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 70° at 5 knots
- Visibility: 20 statute miles
- Lowest ceiling: none
- Temperature: 75 °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 19881212054089A](https://openairdocs.org/incident/19881212054089A), Dec 12, 1988: Hughes 369E, Hanalei, HI, Substantial damage. Engine quit on sightseeing flight. Autorotated to beach. Start fuel flow set too rich. Pilot did not note overtemp.

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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