# NTSB LAX94LA236: Sharp Scorpion TOO, N288JS, Beckwourth, CA, June 2, 1994 - Type: NTSB accident investigation - Classification: Accident · Fatal · Limited investigation · Final report - Date: June 2, 1994, 13:00 local (20:00 UTC) - Place: Beckwourth, CA - Coordinates: 39.790317, -120.460906 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.7903&lon=-120.4609&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Fatal - Injuries: 1 fatal - Status: Completed, report December 7, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 28757 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX94LA236 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/28757/pdf - Page: https://openairdocs.org/ntsb/LAX94LA236 ## Probable cause the failure of the tail rotor 'V' drive belt for undetermined reasons and the subsequent failure and separation of the tail rotor. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, cruise - rotor system - separation (cause) - Loss of control - in flight, cruise - normal - aircraft control - not possible, pilot in command - In flight collision with terrain/water, descent - uncontrolled ## Analysis Ground witnesses reported that the helicopter was cruising about 200 feet agl when popping sounds were heard. Parts then came off the helicopter and it descended rapidly to impact. Witnesses on the airport indicated this was the third flight of the day and that the builder/pilot may have been performing test flights. An FAA inspector reported that the tail rotor assembly was found about 90 yards from the main wreckage along with portions of a 'V' drive belt used to power the tail rotor. Color transfers similar to the drive belt material were found on the blades. The mode of belt failure was not determined. FAA records show the pilot held a private pilot certificate with an airplane single-engine land rating and did not hold a rotorcraft category rating. No evidence was found of a solo endorsement for helicopters. The last medical certificate issued to the pilot was dated March 8, 1988. No information was available concerning the last maintenance inspection. ## Factual narrative On June 2, 1994, about 1300 Pacific daylight time, a homebuilt experimental Sharp Scorpion Too helicopter, N288JS, sustained an in-flight separation of the tail rotor system and crashed about 1 mile west of Beckwourth, California. The helicopter was built, owned, and operated by the pilot. Visual meteorological conditions prevailed at the time and no flight plan was filed for the operation. The helicopter was destroyed in the accident sequence. The private pilot, the sole occupant, sustained fatal injuries. The flight originated from the Beckwourth airport on the day of the accident about 1230 as a presumed local area personal flight. Ground witnesses reported that the helicopter departed from the Beckwourth airport and was cruising about 200 feet agl when popping sounds were heard. The witnesses observed parts come off the helicopter, then it descended rapidly to ground impact. Information from individuals on the airport indicated this was the third flight of the day and that the builder/pilot may have been performing test flights. A Federal Aviation Administration (FAA) inspector from the Reno, Nevada, Flight Standards District Office responded to the accident site and examined the wreckage. He reported that the tail rotor assembly was found about 90 yards from the main wreckage along with portions of a 'V' drive belt, apparently used to power the tail rotor. Color transfers similar to the drive belt material were found on the blades. The inspector was unable to determine the mode of failure of the drive belt. According to FAA records, the pilot held a private pilot certificate with an airplane single-engine land rating. The pilot did not hold a rotorcraft category rating and no evidence was found of a solo endorsement for helicopters. The last medical certificate issued to the pilot was dated March 8, 1988. No information was available concerning the last periodic inspection performed on the helicopter. FAA records disclosed that the helicopter was first issued an experimental airworthiness certificate in the amateur built category on December 27, 1987. The helicopter reportedly had accrued a total time of 66 hours. ## Aircraft - Registration: [N288JS](https://openairdocs.org/deregistered/N288JS-2013-07-02), registration cancelled 2013-07-02, S/N SH 1, built 1987 (OpenAirDocs) - Reported make and model: SHARP SCORPION TOO (SCORPION T) - Registry model: [Sharp Jim SCORPION TOO](https://openairdocs.org/model/sharp-jim-scorpion-too) (registry code 13025FV) (OpenAirDocs) - Registry engine: [Rotorway RW-133 series](https://openairdocs.org/engine/rotorway-rw-133-series) (registry code 55000, reciprocating) (OpenAirDocs) - Category: Helicopter, amateur-built - Serial number: SH-1 - Airframe hours: 66 - Engines: ROTORWAY RW-133 160 horsepower reciprocating - Damage: Destroyed - Flight: Personal, Part 91 - Operator: James L. Sharp - Registered owner: James L. Sharp - Airworthiness certificate: Special, Experimental (Special) - Departed: O02 ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 67; private; airplane ratings: single-engine land; medical: expired; toxicology performed; flight hours: 1,200 total, 66 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 220° at 20 knots - Visibility: 30 statute miles - Lowest ceiling: none - Temperature: 72 °F, dew point 28 °F - Altimeter: 30.00 inHg - Observed at: TRK, 16 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 19940602013399A](https://openairdocs.org/incident/19940602013399A), Jun 2, 1994: Amtrrw SCORPION2, Beckwourth, CA, Destroyed, 1 fatal. Popping sound parts came off. Homebuilt copter struck ground. Lost tail rotor. Drive belt broke. Not rated in type. 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.