# NTSB LAX96LA150: Lampert Revolution M500, N750GL, San Carlos, CA, March 31, 1996 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: March 31, 1996, 13:47 local (21:47 UTC) - Place: San Carlos, CA - Coordinates: 37.490085, -122.259399 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=37.4901&lon=-122.2594&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report January 17, 1997 - Report: Approved by Office Director - NTSB case key (mKey): 29403 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX96LA150 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/29403/pdf - Page: https://openairdocs.org/ntsb/LAX96LA150 ## Probable cause the pilot's failure to recognize a drive train disengagement and initiate an autorotation. The inadequate engine-to-transmission drive belt/pulley design, and the pilot's limited training and experience in rotorcraft operations were factors in this accident. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, approach - vfr pattern - final approach - rotor drive system,main rotor drive belt - shifted (contributing factor) - acft/equip,inadequate design, kit manufacturer (contributing factor) - rotor drive system,main rotor drive belt - disintegrated - rotor drive system,engine to transmission drive - disengaged - In flight collision with terrain/water, landing - flare/touchdown - unsafe/hazardous condition - not identified, pilot in command (cause) - lack of total experience in kind of aircraft, pilot in command (contributing factor) - autorotation - not performed, pilot in command (cause) - Roll over, landing - roll ## Analysis According to FAA airman records, the pilot did not hold a rotorcraft category rating. FAA inspectors examined the pilot's logbook and reported that he received a solo endorsement in helicopters about 1 1/2 years ago. The pilot was returning to the airport following a local area flight. About 1 mile west of the airport, the pilot began to smell something burning and said he sensed something was wrong. Shortly thereafter, he heard a 'slap' sound as the helicopter transitioned through 50 feet and 50 knots about 1/4 mile from the runway. The pilot stated that he 'didn't do anything [with the controls] but keep it headed for an open area between the taxiway and the runway.' The pilot said he did not flare or touch the collective, and the helicopter hit hard in the open area and rolled on its left side. An FAA airworthiness inspector examined the helicopter and found the engine to transmission drive belt fragmented, with rubber transfer throughout the engine compartment. Rubber transfer on the pulleys showed a forward movement pattern of the belt off the pulley. The inspector reported that the pulley was designed without a flange or other means to keep the belt aligned. ## Factual narrative On March 31, 1996, at 1347 hours Pacific standard time, a homebuilt experimental Lampert Revolution M500 helicopter, N750GL, collided with the ground and rolled over during landing at San Carlos, California. The aircraft was owned, built, and operated by the pilot. Visual meteorological conditions prevailed at the time and no flight plan was filed. The helicopter sustained substantial damage. The non-rotorcraft rated private pilot, the sole occupant, sustained minor injuries. The flight originated at Half Moon Bay, California, on the day of the accident at 1315 as a personal cross-country flight to San Carlos. According to FAA airman records, the pilot does not hold a rotorcraft category rating. FAA inspectors examined the pilot's logbook and reported that he received a solo endorsement in helicopters about 1 1/2 years ago. The pilot reported that he flew from San Carlos to Half Moon Bay earlier in the day and was returning to the San Carlos airport. About 1 mile west of the airport the pilot began to smell something burning and said he "sensed something was wrong." Shortly thereafter, he heard a "slap" sound as the helicopter transitioned through 50 feet and 50 knots about 1/4 mile from the runway. The pilot stated that he "didn't do anything [with the controls] but keep it headed for an open area between the taxiway and the runway." The pilot said he did not flare or touch the collective and the helicopter hit hard in the open area and rolled on its left side. An FAA airworthiness inspector examined the helicopter and found the engine to transmission drive belt fragmented, with rubber transfer throughout the engine compartment. Rubber transfer on the pulleys showed a forward movement pattern of the belt off the pulley. The inspector reported that the pulley is designed without a flange or other means to keep the belt aligned. ## Aircraft - Registration: [N750GL](https://openairdocs.org/deregistered/N750GL-2018-01-26), registration cancelled 2018-01-26, S/N 0062 (OpenAirDocs) - Reported make and model: LAMPERT REVOLUTION M500 (REVOLUTION) - Registry model: [Lampert Gary Mitchel REVOLUTION HELI M500](https://openairdocs.org/model/lampert-gary-mitchel-revolution-heli-m500) (registry code 05602HV) (OpenAirDocs) - Category: Helicopter, amateur-built - Serial number: 0062 - Airframe hours: 70 - Engines: Rotax 582 70 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Gary M. Lampert - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, January 25, 1996, 70 hours before - Departed: HAF, HALF MOON BAY, CA - Destination: SQL - Airport: SQL, San Carlos ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 45; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; seat: center; flight hours: 310 total, 70 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 180° at 12 knots - Visibility: 30 statute miles - Lowest ceiling: 15,000 ft broken - Temperature: 77 °F, dew point 34 °F - Altimeter: 29.00 inHg - Observed at: SQL ## 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 19960331005639A](https://openairdocs.org/incident/19960331005639A), Mar 31, 1996: San Carlos, CA, Substantial damage. On final, decared emergency, dropped 20FT, flipped onto its left side. 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.