# NTSB LAX94LA174: Hughes 369D, N113RS, Hi. Nat'L Park, HI, March 26, 1994 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: March 25, 1994, 14:50 local (Mar 26, 1994, 00:50 UTC) - Place: Hi. Nat'L Park, HI - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed, report November 14, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 28705 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX94LA174 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/28705/pdf - Page: https://openairdocs.org/ntsb/LAX94LA174 ## 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 contact with the ground. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, hover - weather condition - whiteout - in-flight planning/decision - poor, pilot in command (cause) - vfr flight into imc - inadvertent, pilot in command (cause) - visual lookout - restricted, pilot in command (cause) - In flight collision with terrain/water, descent - uncontrolled ## Analysis THE PILOT ENCOUNTERED A STEAM CLOUD WHILE HOVERING AND COLLIDED WITH MOUNTAINOUS TERRAIN NEAR A VOLCANO VENT. THE PILOT LOST VISUAL CONTACT WITH THE GROUND WHILE AT A 5-FOOT HOVER AFTER BEING ENVELOPED BY THE STEAM CLOUD. THE PILOT ATTEMPTED TO REGAIN VISUAL CONTACT WITH THE GROUND BY DESCENDING. DURING THE DESCENT, THE HELICOPTER'S LEFT SKID STRUCK A ROCK. THE HELICOPTER ROLLED RIGHT AND STRUCK THE GROUND. ## Factual narrative On March 25, 1994, about 1450 hours Hawaii standard time, a Hughes 369D, N113RS, encountered a steam cloud while hovering and collided with mountainous terrain by the Pu'uoo Vent in the Hawaii National Park, Hawaii. The pilot was conducting a local visual flight rules air taxi flight under 14 CFR 135. The helicopter, operated by Mauna Kea Helicopters, Inc., Hilo, Hawaii, was substantially damaged. The certificated commercial pilot and passenger sustained minor injuries. Visual meteorological conditions prevailed. The flight originated at Hilo, Hawaii, at 1415 hours. The pilot indicated he lost visual contact with the ground while at a 5-foot hover after being enveloped by the steam cloud. The pilot attempted to regain visual contact with the ground by descending. During the descent, the helicopter's left skid struck a rock. The helicopter rolled right and struck the ground. The passenger told park rangers that the helicopter became enveloped in a steam cloud while at a 40-foot hover. The pilot lost control and the helicopter collided with terrain. Access to the helicopter was thwarted by sulfuric fumes from the steam. The pilot and passenger walked about 2 miles before being picked up by a rescue helicopter. The pilot also indicated in his accident report that there were no mechanical failures or malfunctions with the helicopter before the accident. ## 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: 8133 - Engines: ALLISON C20B 420 horsepower turbo shaft - Damage: Substantial damage - Flight: Part 135 - Operator: Mauna Kea Helicopters - Registered owner: Mauna Kea Helicopters, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, March 8, 1994, 60 hours before - Departed: ITO, HILO, HI - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 36; commercial; instrument ratings: helicopter; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 5,025 total, 3,009 in this make and model, 4,525 as pilot in command, 139 in the last 90 days, 75 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 10° at 15 knots - Visibility: 4 statute miles - Lowest ceiling: 2,300 ft overcast - Temperature: 70 °F, dew point 66 °F - Altimeter: 29.00 inHg - Observed at: ITO, 24 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 19940325006579A](https://openairdocs.org/incident/19940325006579A), Mar 25, 1994: Hughes 369D, Hawaii Natl Par, HI, Substantial damage. During hover became enveloped in steam cloud from volcanic vent. Lost control. Skid hit. Helicopter rolled over. ## 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 LAX93LA071](https://openairdocs.org/ntsb/LAX93LA071), Dec 22, 1992: Hughes 369D (N113RS), Hilo, HI, substantial damage. 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… 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.