# NTSB LAX00TA186: McDonnell Douglas 500N, N955SD, Los Angeles, CA, May 8, 2000 - Type: NTSB accident investigation - Classification: Accident · No injuries · Final report - Date: May 8, 2000, 09:25 local (16:25 UTC) - Place: Los Angeles, CA - Location: 34.0522° N, 118.2437° W: Placed by OpenAirDocs: center of Los Angeles, CA, within about 12 miles (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=34.0522&lon=-118.2437&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report July 17, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 49152 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX00TA186 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/49152/pdf - Page: https://openairdocs.org/ntsb/LAX00TA186 ## Probable cause The combined failure of the operator management and the check pilot to ensure the landing area was suitable for the slide on landing. Factors were the high vegetation that entangled the skids, resulting in the abrupt stop and nose down movement of the helicopter, and the training pilot's inappropriate response to the nose pitch down. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - On ground/water encounter with terrain/water, landing - roll - terrain condition - grass - terrain condition - high vegetation (contributing factor) - run on landing - attempted, dual student - proper assistance - not obtained, company/operator management (cause) - procedure inadequate, company/operator management (cause) - unsuitable terrain or takeoff/landing/taxi area - not verified, check pilot (cause) - misc rotorcraft,main rotor/tail boom contact - cut/severed - remedial action - improper, dual student (contributing factor) ## Analysis The flight instructor reported the purpose of the flight was to practice emergency procedures as part of routine intradepartmental training. The training was being conducted in an open field on property owned by the Sheriff's Department. The flight instructor stated that they often utilized the field for flight training purposes, and reported that he had done some training there about 1-week prior. He reported that they performed a high reconnaissance of the field prior to landing and he noted nothing unsuitable about the terrain. A ground survey was not performed prior to the conduct of training flights and landings in the field. The flight instructor stated that he reduced the throttle to ground idle about 10 to 12 feet agl to simulate a total power loss. The pilot trainee was on the controls; he landed the helicopter with no problems. The flight instructor stated that the helicopter slid forward only a few feet, then stopped abruptly. The skids had become entangled in some 18-inch-tall grass and imbedded vines, causing unexpected friction. He stated that the natural tendency to input aft cyclic to stop the aircraft from going over caused the main rotor blades to contact the tail boom. ## Factual narrative On May 8, 2000, at 0925 hours Pacific daylight time, a McDonnell Douglas 500N helicopter, N955SD, sustained substantial damage while performing off-airport landing training in Los Angeles, California. The helicopter was being operated by the Los Angeles County Sheriff's Department as a public-use aircraft under the provisions of 14 CFR Part 91. The commercial rated flight instructor and commercial rated pilot trainee were not injured. The local area instructional flight originated at the Long Beach, California, airport, about 0830. Visual meteorological conditions prevailed and no flight plan was filed. The flight instructor reported that the purpose of the flight was to practice emergency procedures as part of routine intradepartmental training. They were conducting the training in an open field on property owned by the Sheriff's Department. The flight instructor stated that they often utilized the field for flight training purposes, and reported that he had done some training there about 1 week prior to the accident. He reported that they performed a high reconnaissance of the field prior to landing; at that time he noted nothing unsuitable about the terrain. The flight instructor stated about 10 to 12 feet above ground level (agl), he reduced the throttle to ground idle to simulate a total power loss. The pilot trainee was on the controls; he landed the helicopter with no problems. The flight instructor stated that the helicopter slid forward only a few feet, then stopped abruptly. The skids had become entangled in 18-inch-tall grass and imbedded vines, causing unexpected friction. He stated that the natural tendency to input aft cyclic to stop the aircraft from going over caused the main rotor blades to contact the tail boom. The flight instructor reported that neither he nor the pilot trainee had seen the high vegetation before landing, nor had they ever noted it there in the field before. ## Aircraft - Registration: [N955SD](https://openairdocs.org/deregistered/N955SD-2004-07-26), registration cancelled 2004-07-26, S/N LN080, built 1996 (OpenAirDocs) - Reported make and model: McDonnell Douglas 500N - Registry model: [Mcdonnell Douglas Helicopter 500N](https://openairdocs.org/model/mcdonnell-douglas-helicopter-500n) (registry code 3027374) (OpenAirDocs) - Registry engine: [Allison 250-C20 series](https://openairdocs.org/engine/allison-250-c20-series) (registry code 03020, turbo-prop) (OpenAirDocs) - Category: Helicopter - Serial number: LN080 - Airframe hours: 2802 - Engines: Allison 250-C20 450 horsepower turbo shaft - Damage: Substantial damage - Flight: Public aircraft, Part 91 - Registered owner: Los Angeles County Sheriff Dpt - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, June 21, 1999, 64 hours before - Departed: LGB, LONG BEACH, CA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 55; commercial; airplane ratings: multi-engine land, single-engine land, single-engine sea; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: right; flight hours: 13,494 total, 865 in this make and model, 13,422 as pilot in command, 80 in the last 90 days, 15 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: variable at 5 knots - Visibility: 15 statute miles - Lowest ceiling: 17,000 ft broken - Temperature: 68 °F, dew point 59 °F - Altimeter: 30.00 inHg - Observed at: EMT ## 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 20000508036159A](https://openairdocs.org/incident/20000508036159A), May 8, 2000: Hughes 500N, Los Angeles, CA, Substantial damage. (-23) On may 8, 2000 at approx. 9:25 am PDT, a Mcdonnell Douglas 520N helicopter, N955SD, sustained substantial damage while performing off-airport training in… 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.