# NTSB LAX99FA137: Mbb B0-105CBS-4, N105HH, Indian Springs, NV, April 4, 1999 - Type: NTSB accident investigation - Classification: Accident · Fatal · Field investigation · Final report - Date: April 3, 1999, 23:50 local (Apr 4, 1999, 07:50 UTC) - Place: Indian Springs, NV - Coordinates: 36.509216, -115.640792 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=36.5092&lon=-115.6408&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Fatal - Injuries: 3 fatal - Status: Completed, report December 4, 2000 - Report: Approved by Office Director - NTSB case key (mKey): 46117 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX99FA137 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/46117/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=46117 - Page: https://openairdocs.org/ntsb/LAX99FA137 ## Probable cause the pilot's decision to continue VFR flight in deteriorating IFR conditions resulting in spatial disorientation and subsequent loss of control. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight encounter with weather, maneuvering - weather condition - snow - light condition - dark night - updating of recorded weather information - not performed, pilot in command - flight into adverse weather - attempted, pilot in command (cause) - Loss of control - in flight, maneuvering - aircraft control - not maintained, pilot in command (cause) - spatial disorientation, pilot in command (cause) - In flight collision with terrain/water, descent - uncontrolled - terrain condition - rising ## Analysis The medical evacuation helicopter was on a positioning flight back to its remote base location on a dark night. The pilot received a weather briefing at 1700; however, there was no record of him receiving an update. The area forecast was for broken clouds, scattered light rain showers, instrument flight rules (IFR) conditions, strong northerly winds over rough terrain, light to occasional moderate rime icing in precipitation, and a freezing level between 7,000 and 9,000 feet mean sea level. A winter advisory was in effect for 2 to 3 inches of snow with winds from the southeast at 13 to 22 knots. A motorist saw the helicopter flying west over a highway leading to the accident site at 1,000 feet above ground level (AGL). The sky was overcast with freezing rain that turned into wet snow and then finally freezing sleet. A second motorist nearer the accident site saw the helicopter using its searchlight to follow the highway at 150 to 200 feet AGL in conditions of lower clouds and reduced visibility. A resident next to the accident site heard the helicopter flying back and forth for a few minutes followed by the crash. He drove in the direction of the sound and found the crash site in flames. Snow had reduced visibility to less than 50 yards at the time. The aircraft was not certified for flight in IFR conditions; however, it had full flight instruments, a radar altimeter, a GPS, and VHF navigational radios. The operator reported the pilot had undergone an inadvertent instrument meteorological conditions evaluation within the last 90 days; however, documentation of this training was not found. ## Factual narrative HISTORY OF FLIGHT On April 3, 1999, about 2350 hours Pacific standard time, a Messerschmitt-Bolkow-Blohm (Mbb) BO-105CBS-4, N105HH, with the call sign Lifeguard 2, was en route to Pahrump, Nevada, when it collided with terrain and burned while maneuvering near Indian Springs, Nevada. The aircraft was destroyed and the certificated airline transport pilot and his two medical crewmembers received fatal injuries. The aircraft was operated as a positioning flight under 14 CFR Part 91 by Metro Aviation, Inc., when the accident occurred. The flight originated from Las Vegas, Nevada, about 2315 on April 3, 1999. Instrument meteorological conditions prevailed at the accident site and a company flight plan had been filed. The aircraft departed Valley Hospital Medical Center in Las Vegas after delivering a patient. The purpose of the flight was to reposition the aircraft at its home base at Hidden Hills Airport, Pahrump, Nevada. A motorist, who was westbound on U.S. highway 95 near the overpass at state highway 156, reported seeing a helicopter with a flashing strobe light flying over the highway in the same direction on the night of the accident. He estimated the aircraft's altitude at that time to be about 1,000 feet agl. He stated that the sky was overcast with freezing rain that turned into wet snow and then finally freezing sleet. Within a few minutes, the freezing precipitation had obscured the forward vision through his windshield. His windshield wipers were unable to remove the frozen accumulation and he was forced to roll down his driver's side window in order to obtain any forward visibility. As the intensity of the snow increased, he slowed his speed from 70 mph to about 35 mph. During this time he passed another vehicle, with its emergency flashers on, that had stopped along the highway. A second motorist was traveling southeast bound toward Las Vegas but had not reached Indian Springs when he saw a helicopter flying about 150 to 200 feet overhead in the opposite direction on the night of the accident. The helicopter was using its searchlight as it followed the highway but would then suddenly fly away from the highway only to return a short time later. At one point, the pilot illuminated another car with his searchlight and seemed to be following it for a time. By the time the first motorist reached Indian Springs, he estimated that visibility was about 50 feet with winds from the south about 10 mph. He went inside his motor home and a few minutes later heard a "thump." A second resident of Indian Springs reported that he heard the sounds of an aircraft flying back and forth in what he thought was a north-south direction for about 10 minutes. Finally, the engine noise became so faint that he was unable to hear it; however, a few minutes later the engine noise returned. He heard the engine sounds for a few more minutes and then heard a "big thump." Thinking that the aircraft had crashed, he drove toward the origin of the sound and found the crash site in flames. He estimated that snow had reduced visibility to less than 50 yards at the time. PERSONNEL INFORMATION The pilot was a former military pilot and had served in the Soviet Air Force. He had logged a total of 10,920 hours, 6,580 of which were in helicopters, with about 3,592 hours of instrument time. He had accumulated about 187 hours in this make and model helicopter and had flown about 3 hours during the preceding 24 hours. He had worked for the operator as an emergency medical services (EMS) pilot for about 1 year. The operator reported that he had satisfactorily completed an inadvertent meteorological condition (IMC) evaluation within the last 90 days. The operator provided copies of his training records showing that he had satisfactorily completed an unusual attitude recovery evaluation on April 30, 1998. A further review of the training records showed that the training form content had been revised. The last record that specifically documents inadvertent IMC training in combination with unusual attitude recovery was dated October 22, 1997; however, on that date inadvertent IMC procedures for the pilot were not evaluated. The operator did not provide any additional records. AIRCRAFT INFORMATION The aircraft was not certified for instrument flight; however, it was equipped with flight instruments to include an attitude indicator, a horizon situation indicator (HSI), a radar altimeter, a global positioning system (GPS), and very high frequency (VHF) navigational radios. The radar altimeter provides an aural warning as the aircraft descends through a predesignated altitude; however, continued operation below this altitude will not result in subsequent warnings regardless of terrain proximity. The forward windscreen was equipped with external windshield wipers and an internal defroster utilizing engine bleed air. The aircraft was approved for flight in wet snow, in accordance with airworthiness directive (AD) No. 90-23-08-RO, and Mbb service bulletin (SB)-BO 105-80-108. A review of the aircraft maintenance forms and records by Safety Board investigators did not reveal any discrepancies. The operator estimated that the aircraft had about 120 gallons of Jet A onboard at the time of the last departure. METEOROLOGICAL INFORMATION Federal Aviation Administration (FAA) records disclosed that the pilot had accessed the Data Transformation Corporation (DTC) commercial weather service at 1900 on the evening of the accident. The service allows pilots to obtain weather information on-line through a Direct User Access Terminal (DUAT) via the Internet, including color radar graphics. There were no records of subsequent weather updates. The destination, Hidden Hills Airport, Pahrump, does not have weather reports or forecasts issued for that location. The closest reporting station is Desert Rock Airport, Mercury, Nevada, 43 miles to the north; however, terminal forecasts, as such, are valid only within a 5-mile radius of the airport. The 2356 weather observation for Desert Rock Airport reported winds from 110 degrees at 3 knots; 9 miles visibility; an overcast ceiling of 1,900 feet agl; temperature of 36 degrees; and dew point of 32 degrees Fahrenheit. Unknown precipitation began at 2312. (Unknown precipitation is reported by automated systems when the system can not determine the type of precipitation that is falling, i.e., ice pellets, snow pellets, snow grain, graupel, ice needles, drizzle, freezing drizzle, or a combination of those listed.) The closest upper air data observation was also located at Desert Rock Airport. At 2100, the sounding indicated that the air was saturated from the surface up to 16,000 feet msl. The freezing level was at the surface (3,310 feet msl), with winds from 210 degrees at 5 knots. The current area forecast for southern Nevada had been issued at 1945, and was valid until 0800. It forecast broken clouds at 7,000 feet msl, scattered light rain showers, and light snow over the mountains. AIRMET Sierra issued at 1845 forecast mountain obscuration in clouds and precipitation. AIRMET Sierra update No. 1 that was issued at 2335 forecast IFR conditions and mountain obscuration until 0600. AIRMET Tango issued at 1845 forecast occasional moderate turbulence below 16,000 feet msl. AIRMET Tango update No. 1 that was issued at 2345 forecast moderate turbulence below 16,000 feet msl, as well as strong northerly winds over rough terrain. AIRMET Zulu, issued at 1845, forecast light to occasional moderate rime icing in precipitation below 18,000 feet msl. AIRMET Zulu update No. 1 that was issued at 2345 forecast the freezing level to be between 7,000 and 9,000 feet msl. At 2309, the National Weather Service (NWS) Las Vegas Regional Office issued a winter advisory for snow and blowing snow. With 4 inches of snow already reported to have fallen, an additional 2 t ## Aircraft - Registration: [N105HH](https://openairdocs.org/deregistered/N105HH-2000-05-11), registration cancelled 2000-05-11, S/N S-339 (OpenAirDocs) - Reported make and model: Mbb B0-105CBS-4 (B0-105CBS-) - Registry model: [Messerschmitt-Boelkow-Blohm BO-105S](https://openairdocs.org/model/messerschmitt-boelkow-blohm-bo-105s) (registry code 5626006) (OpenAirDocs) - Category: Helicopter - Serial number: 0339 - Airframe hours: 5763 - Engines: Allison 250-C20B 420 horsepower turbo shaft - Damage: Destroyed - Flight: Positioning, Part 91 - Operator: Mike Stanberry, doing business as Metro Aviation, Inc. - Registered owner: Bruce D. Gray - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, March 10, 1999, 29 hours before - Departed: LAS VEGAS, NV - Destination: L57, PAHRUMP, NV - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 42; flight instructor, commercial, airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: helicopter, airplane; medical: class 1, valid medical--no waivers/lim.; seat: right; toxicology performed; flight hours: 10,920 total, 187 in this make and model, 7,630 as pilot in command, 47 in the last 90 days, 15 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Instrument (IMC), Night/dark - Wind: 110° at 3 knots - Visibility: 9 statute miles - Lowest ceiling: 1,900 ft overcast - Temperature: 36 °F - Altimeter: 29.00 inHg - Observed at: DRA, 17 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 19990404002919A](https://openairdocs.org/incident/19990404002919A), Apr 4, 1999: Bolkms BO105S, Indian Springs, NV, Destroyed, 3 fatal. Metro aviation acft (a 1998 messerschmitt-boelkow-blohm BO-1055 helicopter) air ambulance crashed on a road under unknown circumstances, all 3 POB (the pilot… ## Docket (23 files) The files NTSB released with the investigation on October 6, 2000, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=46117. 7.5 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1/2 (item 1, .PDF, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40405591&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1%2F2-Redacted.PDF - Supplement C (item 2, .PDF, 449 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40129909&FileExtension=.PDF&FileName=Supplement%20C-Master.PDF - Supplement D (item 3, .PDF, 504 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40129912&FileExtension=.PDF&FileName=Supplement%20D-Master.PDF - Supplement K (item 4, .PDF, 421 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40129910&FileExtension=.PDF&FileName=Supplement%20K-Master.PDF - Supplement S (item 5, .PDF, 71 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40129911&FileExtension=.PDF&FileName=Supplement%20S-Master.PDF - Meteorology 5 - Factual Report of Group Chairman (item 6, .PDF, 2.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40405592&FileExtension=.PDF&FileName=Meteorology%205%20-%20Factual%20Report%20of%20Group%20Chairman-Redacted.PDF - Witness Statements (item 7, .PDF, 278 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40405594&FileExtension=.PDF&FileName=Witness%20Statements-Redacted.PDF - Maps or Charts of Accident Area, Wreckage Diagrams (item 8, .PDF, 389 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40129916&FileExtension=.PDF&FileName=Maps%20or%20Charts%20of%20Accident%20Area,%20Wreckage%20Diagrams-Master.PDF - Aircraft Accident Report from Federal Aviation Administration (item 9, .PDF, 106 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40405597&FileExtension=.PDF&FileName=Aircraft%20Accident%20Report%20from%20Federal%20Aviation%20Administration-Redacted.PDF - Report from Las Vegas Metropolitan Police Department (item 10, .PDF, 148 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40405598&FileExtension=.PDF&FileName=Report%20from%20Las%20Vegas%20Metropolitan%20Police%20Department-Redacted.PDF - Metro Aviation Training Records (item 11, .PDF, 173 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40405599&FileExtension=.PDF&FileName=Metro%20Aviation%20Training%20Records-Redacted.PDF - Radar Data (item 12, .PDF, 52 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40405605&FileExtension=.PDF&FileName=Radar%20Data-Redacted.PDF - Airworthiness Directive (item 13, .PDF, 150 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40129931&FileExtension=.PDF&FileName=Airworthiness%20Directive-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 14, .PDF, 421 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40405600&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Redacted.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15 (item 15, .PDF, 56 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40405602&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15-Redacted.PDF - Toxicological Report (item 16, .PDF, 74 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40405604&FileExtension=.PDF&FileName=Toxicological%20Report-Redacted.PDF - Photo 1. Accident site within 1 hour of accident. Weather continues as described by witnesses at the time of accident. Photo by Las Vegas Metro P.D. (item 17, .PDF, 57 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40129923&FileExtension=.PDF&FileName=Photo%201.%20%20Accident%20site%20within%201%20hour%20of%20accident.%20%20Weather%20continues%20as%20described%20by%20witnesses%20at%20the%20time%20of%20accident.%20%20Photo%20by%20Las%20Vegas%20Metro%20P.D.-Master.PDF - Photo 2. Aerial photograph of accident site. Arrow indicates aircraft direction. Photo by Las Vegas Metro P.D. (item 18, .PDF, 58 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40129924&FileExtension=.PDF&FileName=Photo%202.%20%20Aerial%20photograph%20of%20accident%20site.%20%20Arrow%20indicates%20aircraft%20direction.%20%20Photo%20by%20Las%20Vegas%20Metro%20P.D.-Master.PDF - Photo 3. View of main ground scar looking toward 188 degrees. Burn area is in the background. (item 19, .PDF, 62 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40129925&FileExtension=.PDF&FileName=Photo%203.%20%20View%20of%20main%20ground%20scar%20looking%20toward%20188%20degrees.%20%20Burn%20area%20is%20in%20the%20background.-Master.PDF - Photo 4. Flattened toe of skid. (item 20, .PDF, 45 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40129926&FileExtension=.PDF&FileName=Photo%204.%20%20Flattened%20toe%20of%20skid.-Master.PDF - Photo 5. Tail rotor blade. (item 21, .PDF, 41 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40129927&FileExtension=.PDF&FileName=Photo%205.%20%20Tail%20rotor%20blade.-Master.PDF - Photo 6. Tail rotor blade. (item 22, .PDF, 42 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40129928&FileExtension=.PDF&FileName=Photo%206.%20%20Tail%20rotor%20blade.-Master.PDF - Photo 7. Layout of main rotor blades. (item 23, .PDF, 58 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40129929&FileExtension=.PDF&FileName=Photo%207.%20%20Layout%20of%20main%20rotor%20blades.-Master.PDF 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.