# NTSB LAX93LA071: Hughes 369D, N113RS, Hilo, HI, December 22, 1992 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: December 21, 1992, 14:00 local (Dec 22, 1992, 00:00 UTC) - Place: Hilo, HI - Coordinates: 19.690269, -155.080703 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=19.6903&lon=-155.0807&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 5 uninjured - Status: Completed, report August 30, 1993 - Report: Approved by Office Director - NTSB case key (mKey): 27888 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX93LA071 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27888/pdf - Page: https://openairdocs.org/ntsb/LAX93LA071 ## Probable cause THE BEARING FAILURES DUE TO THE OPERATOR'S USE OF IMPROPER MAINTENANCE INSPECTION AND OVERHAUL PROCEDURES BY INSTALLING AN UNSERVICEABLE COMPRESSOR MODULE IN THE HELICOPTER ENGINE. FACTORS IN THE ACCIDENT WERE THE UNSUITABLE NATURE OF THE TERRAIN FOR THE FORCED LANDING AND THE TAIL WIND CONDITION DURING THE LANDING TOUCHDOWN. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - mech failure/malf, cruise - normal - compressor assembly - previous damage - maintenance,overhaul - not performed, company maintenance personnel (cause) - maintenance,inspection - improper, company maintenance personnel (cause) - engine assembly,bearing - failure,total (cause) - Forced landing, descent - emergency - Hard landing, landing - flare/touchdown - terrain condition - none suitable (contributing factor) - weather condition - tailwind (contributing factor) ## Analysis DURING CRUISE THE PILOT DETECTED A BUFFETING IN THE AIRFRAME FOLLOWED BY A LEFT YAW. THE ENGINE GAGES INDICATED DECREASING POWER OUTPUT WITH A HIGH TURBINE OUTLET TEMPERATURE, AND, THE ENGINE CHIP AND FAILURE LIGHTS ILLUMINATED. THE PILOT EXECUTED AN AUTO ROTATION AND HAD TO STRETCH THE GLIDE SLIGHTLY TO REACH THE ONLY SUITABLE AREA WHICH INVOLVED A DOWN WIND LANDING. THE MAIN ROTOR SLICED OFF THE TAIL BOOM AS THE HELICOPTER SLID TO A STOP. REVIEW OF THE OPERATORS DAILY FLIGHT SHEETS FOR THE ACCIDENT HELICOPTER REVEALED THAT A ENGINE CHIP LIGHT HAD ILLUMINATED ON THE FLIGHT PRIOR TO THIS ONE. THE CORRECTIVE ACTION TAKEN WAS TO CLEAN THE CHIP PLUG AND REINSTALL IT. NO TEST FLIGHT AND FURTHER CHECK OF THE PLUG WAS DONE AS REQUIRED IN THE MAINTENANCE MANUALS. DISASSEMBLY OF THE ENGINE REVEALED THAT THE NUMBER 1 AND 2 BEARINGS IN THE COMPRESSOR MODULE HAD FAILED. REVIEW OF MAINTENANCE RECORDS REVEALED THAT THE COMPRESSOR MODULE WAS FORMERLY INSTALLED IN AN ENGINE WHICH WAS INVOLVED IN A HELICOPTER ACCIDENT IN MAY OF 1992. THE COMPRESSOR MODULE WAS NOT DISASSEMBLED FOR INSPECTION AS REQUIRED IN THE OVERHAUL AND MAINTENANCE MANUAL, AND WAS NOT SIGNED OFF FOR RETURN TO SERVICE. IT WAS INSTALLED BY THE OPERATOR IN THE ACCIDENT HELICOPTER ENGINE ON NOVEMBER 21, 1992. ## Aircraft - Registration: [N113RS](https://openairdocs.org/deregistered/N113RS-1997-05-23), registration cancelled 1997-05-23, S/N 590506D (OpenAirDocs) - Reported make and model: HUGHES 369D - Registry model: [Hughes Helicopters HUGHES 369D](https://openairdocs.org/model/hughes-helicopters-hughes-369d) (registry code 4470706) (OpenAirDocs) - Category: Helicopter - Serial number: 590506D - Airframe hours: 6928 - Engines: ALLISON 250 C20B 420 horsepower turbo shaft - Damage: Substantial damage - Flight: Part 135 - Operator: Mauna Kea Helicopters - Registered owner: Mauna Kea Helicopters, Insc. - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, December 7, 1992, 64 hours before - Departed: MUE, KAMUELA, HI - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 30; commercial; airplane ratings: single-engine land; instrument ratings: helicopter; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 4,017 total, 3,643 as pilot in command, 138 in the last 90 days, 71 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 50° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 68 °F - Altimeter: 29.00 inHg ## 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 19921221051009A](https://openairdocs.org/incident/19921221051009A), Dec 21, 1992: Hughes 369D, Hilo, HI, Substantial damage. Losing power, high temp and chip light on. Made hard autorotation landing. Used compressor failed. Not serviced. ## Other investigations on N113RS (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 LAX94LA174](https://openairdocs.org/ntsb/LAX94LA174), Mar 26, 1994: Hughes 369D (N113RS), Hi. Nat'L Park, HI, substantial damage. Probable cause: the pilot's in-flight decision to maneuver the helicopter close to an active volcano steam vent which resulted in a whiteout condition from the steam, and the pilot's subsequent loss of visual… 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.