# NTSB SEA08CA124: Bell 206B, N526DL, Murietta, CA, April 27, 2008 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: April 27, 2008, 14:30 local (21:30 UTC) - Place: Murietta, CA - Coordinates: 33.571109, -117.128334 - Nearby events: https://openairdocs.org/map.md?lat=33.5711&lon=-117.1283&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-flare/touchdown: Hard landing](https://openairdocs.org/ntsb-events/092) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report June 30, 2008 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 67947 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA08CA124 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/67947/pdf - Page: https://openairdocs.org/ntsb/SEA08CA124 ## Probable cause The flight instructor's inadequate supervision and delayed remedial action. A contributing factor to the accident was the dual student's improper flare. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: landing flare](https://openairdocs.org/ntsb-findings/01062041): Aircraft › Aircraft oper/perf/capability · Incorrect use/operation (probable cause); cases with it: [All aircraft, 1,285 cases](https://openairdocs.org/ntsb-findings/01062041/cases.md) - [Attention/monitoring: monitoring other person](https://openairdocs.org/ntsb-findings/02021535): Personnel issues › Psychological · Pilot (probable cause); cases with it: [All aircraft, 200 cases](https://openairdocs.org/ntsb-findings/02021535/cases.md) - [Action: delayed action](https://openairdocs.org/ntsb-findings/02041025): Personnel issues › Action/decision · Instructor/check pilot (probable cause); cases with it: [All aircraft, 894 cases](https://openairdocs.org/ntsb-findings/02041025/cases.md) - [Tail rotor](https://openairdocs.org/ntsb-findings/01046400): Aircraft › Aircraft propeller/rotor · Not specified; cases with it: [All aircraft, 23 cases](https://openairdocs.org/ntsb-findings/01046400/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-flare/touchdown: Hard landing](https://openairdocs.org/ntsb-events/092) (defining event); cases with it: [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) ## Analysis The commercial pilot was receiving instruction and reported that during the seventh practice full touchdown autorotation, the helicopter touched down on the aft part of the landing skids and started to rock forward. He stated he applied aft cyclic to prevent the helicopter from rolling forward, and one of the main rotor blades subsequently struck the tail boom. The flight instructor said that he was unable to react in time to level the helicopter prior to touchdown. Examination of the helicopter revealed structural damage to the tail boom and tail rotor drive shaft. No mechanical anomalies were reported with the flight control system. The pilot stated in the "How could this accident have been prevented?" section of the Pilot/Operator Aircraft Accident/Incident Report form, "proper execution of a full down autorotation by fully leveling the aircraft before touchdown." ## Factual narrative The commercial pilot receiving instruction reported that during the seventh practice autorotation to landing that day, the helicopter touched down on the aft part of the landing skids and started to roll forward. The pilot stated he applied aft cyclic to prevent the helicopter from rolling forward and one of the main rotor blades subsequently struck the tail boom. The flight instructor stated that he was unable to react in time to level the helicopter prior to touchdown. Examination of the helicopter revealed structural damage to the tail boom and tail rotor drive shaft. No mechanical anomalies were reported with the flight control system. The pilot stated in the "how could this accident/incident have been prevented" section of the Pilot/Operator Aircraft Accident Report form, "proper execution of a full down autorotation by fully leveling the aircraft before touchdown." ## Aircraft - Registration: N526DL (not matched to a registry record) - Reported make and model: Bell 206B - Category: Helicopter - Serial number: 3215 - Engines: Allison 250-C20 420 horsepower turbo shaft - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Go Heli LLC - Registered owner: Go Heli LLC - Airworthiness certificate: Standard, Normal - Departed: F70, Murietta, CA - Airport: F70, French Valley Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 39; injuries: none; commercial, flight instructor, airline transport; airplane ratings: single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2; flight hours: 4,296 total, 1,600 in this make and model, 120 in the last 90 days, 49 in the last 30 days - Flight instructor; age 58; injuries: none; flight instructor, commercial, airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2 ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 90 °F, dew point 5 °F - Altimeter: 30.03 inHg - Observed at: KRIV ## 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 20080427836699A](https://openairdocs.org/incident/20080427836699A), Apr 27, 2008: Bell 206B, Murrieta/Temec, CA, Substantial damage. (-23) The helicopter hit the tarmac hard during a practice autorotation. Damage consisted of a nicked main rotor, drive shaft cover damage, and torqued tail… 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.