# NTSB LAX94LA126: Bell 206L-1, N1077N, Barstow, CA, February 15, 1994 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: February 14, 1994, 18:02 local (Feb 15, 1994, 02:02 UTC) - Place: Barstow, CA - Coordinates: 34.859592, -116.81047 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.8596&lon=-116.8105&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious - Status: Completed, report February 14, 1995 - Report: Approved by Office Director - NTSB case key (mKey): 28666 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX94LA126 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/28666/pdf - Page: https://openairdocs.org/ntsb/LAX94LA126 ## Probable cause the pilot's misjudgment of the landing flare altitude during a night autorotation while preoccupied with maintaining proper main rotor rpm. A factor in the accident was the pilot's visual perception which was affected by the outside ambient lighting conditions. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Hard landing, landing - flare/touchdown - light condition - dusk (contributing factor) - visual/aural perception, pilot in command (contributing factor) - autorotation - initiated, pilot in command - flare - misjudged, pilot in command (cause) ## Analysis The pilot intended to do several autorotations at the end of his daily flights to verify a new clutch assembly which was installed on the helicopter that morning. The pilot said that it was twilight, but that he could clearly see the runway lights when he lifted off to do the autorotations. The pilot made one successful autorotation and decided on a second one to check the main rotor rpm. The pilot said that during the second one the main rotor rpm was low, but he did not get a low rotor warning horn or light. The pilot said that during the descent he was trying to bring the main rotor rpm up by varying his airspeed until the flare point. Witnesses reported that the helicopter began a flare about 50 feet above the runway, then landed hard. The helicopter became airborne again, began to spin, and then landed hard, rolling onto its left side. No evidence of mechanical failure was found during an examination of the helicopter. Sunset occurred at 1733 and the end of civil twilight was at 1759. The accident was at 1802. ## Factual narrative On February 14, 1994, about 1802 hours Pacific standard time, a Bell 206L-1, N1077N, crashed during landing at Barstow-Daggett Airport, Barstow, California. The helicopter was engaged in a maintenance test flight performing autorotations to verify the installation of a freewheeling clutch assembly. The helicopter was operated by Aspen Helicopters, Inc., Oxnard, California, and was destroyed by impact. The certificated commercial pilot, the sole occupant, received serious injuries. Visual meteorological conditions prevailed. The flight originated at the Barstow airport on the day of the mishap at 1755 hours. In a verbal statement, the pilot said that he had completed a contract flight for the Department of the Interior and landed at Barstow. The pilot said he intended to do several autorotations to verify a new clutch assembly which was installed on the helicopter and signed off for return to service that morning. The pilot said that it was twilight, but that he could clearly see the runway lights when he lifted off to do the autorotations. The pilot made one successful autorotation and decided to make a second one to check the main rotor autorotational rpm. The pilot reported that during the second autorotation the main rotor rpm was low, but he did not get a low rotor warning horn or light. The pilot said that during the descent he was trying to bring the main rotor rpm up by varying his airspeed until the flare point. Witnesses reported that the helicopter began a flare about 50 feet above the ground on runway 22, then landed hard. The helicopter became airborne again, began to spin, and then landed hard, rolling onto its left side. The helicopter was examined by investigators from the Office of Aviation Safety, U.S. Department of the Interior. They reported finding no evidence of mechanical failure. The operator stated that the engine was still running after the helicopter came to rest and that the pilot shut the engine off. The freewheeling clutch unit was removed from the helicopter and sent to the manufacturer for examination under the supervision of a Federal Aviation Administration (FAA) inspector. No discrepancies were found during the examination. A National Transportation Safety Board computer program was used to determine the times of sunset and the end of civil twilight during the accident flight. According to the data, sunset occurred at 1733, and the end of civil twilight was at 1759. At 1802, the sun was 6.7 degrees below the horizon on a magnetic azimuth of 245.5 degrees. ## Aircraft - Registration: [N1077N](https://openairdocs.org/deregistered/N1077N-1997-03-31), registration cancelled 1997-03-31, S/N 45349 (OpenAirDocs) - Reported make and model: BELL 206L-1 - Registry model: [Bell Helicopter Textron 206L-1](https://openairdocs.org/model/bell-helicopter-textron-206l-1) (registry code 1182107) (OpenAirDocs) - Category: Helicopter - Serial number: 45349 - Airframe hours: 4826 - Engines: ALLISON 250-C30P 675 horsepower turbo shaft - Damage: Destroyed - Flight: Part 91 - Registered owner: Aspen Helicopters Inc. - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, January 22, 1994, 36 hours before - Airport: DAG, Barstow Dagget, runway 4, 5,119 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 51; commercial; airplane ratings: single-engine land; instrument ratings: helicopter, airplane; medical: class 1, valid medical--w/ waivers/lim; seat: right; flight hours: 9,757 total, 1,500 in this make and model, 9,557 as pilot in command, 59 in the last 90 days, 23 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Dusk - Wind: 170° at 5 knots - Visibility: 15 statute miles - Lowest ceiling: none - Temperature: 54 °F, dew point 10 °F - Altimeter: 30.00 inHg - Observed at: DAG ## 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 19940214004279A](https://openairdocs.org/incident/19940214004279A), Feb 14, 1994: Bell 206L1, Daggett, CA, Destroyed. Lost rotor RPM while testing new clutch assembly. Landed hard. Bounced. Came down in spin. Rolled over. ## Other investigations on N1077N (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 FTW81FA056](https://openairdocs.org/ntsb/FTW81FA056), Mar 25, 1981: Bell 206L-1 (N1077N), Gulf Of Mexico (Gulf of Mexico), substantial damage 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.