# NTSB DEN04LA047: Bell 47G-3B-1, N83702, Kremmling, CO, February 13, 2004 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: February 13, 2004, 13:45 local (20:45 UTC) - Place: Kremmling, CO - Coordinates: 40.053333, -106.368331 - Nearby events: https://openairdocs.org/map.md?lat=40.0533&lon=-106.3683&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report June 30, 2004 - Report: Approved by Office Director - Parties: FAA FSDO - NTSB case key (mKey): 58803 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN04LA047 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/58803/pdf - Page: https://openairdocs.org/ntsb/DEN04LA047 ## Probable cause the pilot's failure to attain landing flare and maintain adequate rotor rpm. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Hard landing, landing - aircraft control - not maintained, pilot in command (cause) - adequate rotor rpm - not available (cause) - autorotation - simulated ## Analysis According to the pilot, he was practicing autorotations from an altitude of 800 feet agl when "it appeared that the aircraft had inadequate main rotor rpm." The pilot said he attempted to recover to a hover; however, "sufficient rpm was not available to recover," resulting in a hard landing and substantial damage. ## Factual narrative On February 13, 2004, at approximately 1345 mountain standard time, a Bell, 47G-3B-1, N83702, was substantially damaged during a hard landing at McElroy Airfield, Kremmling, Colorado. The commercial pilot, the sole occupant on board, was not injured. Visual meteorological conditions prevailed. No flight plan had been filed for the local flight being conducted under the provisions of Title 14 CFR Part 91. The flight departed approximately 1230. According to the pilot, he was practicing "power-on recovery, autorotations" from an altitude of 800 feet agl. He said he had completed two autorotations and was attempting a third autorotation when "it appeared that the aircraft had inadequate main rotor rpm." The pilot said he attempted to recover to a hover; however, "sufficient rpm was not available to recover," resulting in a hard landing. During the impact, the vertical stabilizer and both tail rotor blades were bent and the tail rotor short-shaft separated from the long shaft. An examination of the helicopters systems revealed no anomalies. ## Aircraft - Registration: [N83702](https://openairdocs.org/deregistered/N83702-2017-12-01), registration cancelled 2017-12-01, S/N 66-8093, built 1966 (OpenAirDocs) - Reported make and model: Bell 47G-3B-1 - Registry model: [Bell 47G-3B-1](https://openairdocs.org/model/bell-47g-3b-1) (registry code 1181028) (OpenAirDocs) - Registry engine: [Lycoming TVO-435-B1A](https://openairdocs.org/engine/lycoming-tvo-435-b1a) (registry code 41938, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 3593 - Airframe hours: 11523.2 - Engines: Lycoming TVO-435-B1A 270 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, February 4, 2004, 5.4 hours before - Departed: 20V, Kremmling, CO - Airport: 20V, McElroy Airfield ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 43; injuries: none; commercial, flight instructor, private; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; last flight review October 13, 2003; seat: left; flight hours: 687 total, 276 in this make and model, 568 as pilot in command, 18 in the last 90 days, 13 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 18 °F, dew point 1 °F - Altimeter: 30.12 inHg - Observed at: EGE, 36 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 20040213002879A](https://openairdocs.org/incident/20040213002879A), Feb 13, 2004: Bell 47G3B1, Kremmling, CO, Substantial damage. (-23) On 02-20-04 pilot reported a hard landing had occurred the previous weed during practice autorotation landings. Damage included a sheared tailrotor short… ## Other investigations on N83702 (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 CEN13LA463](https://openairdocs.org/ntsb/CEN13LA463), Aug 6, 2013: Bell 47G-3B-1 (N83702), Vinton, IA, substantial damage. Probable cause: The pilot's operation of the helicopter at high gross weight and high density altitude while still in ground effect, which reduced the efficiency of the rotor system and the amount of lift produced,… 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.