# NTSB FTW04LA220: Bell 212, N181W, Umpire, AR, August 24, 2004 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: August 24, 2004, 14:30 local (19:30 UTC) - Place: Umpire, AR - Coordinates: 34.230556, -94.059722 - Nearby events: https://openairdocs.org/map.md?lat=34.2306&lon=-94.0597&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report December 28, 2004 - Report: Approved by Office Director - Parties: FAA/FSDO - NTSB case key (mKey): 59975 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW04LA220 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/59975/pdf - Page: https://openairdocs.org/ntsb/FTW04LA220 ## Probable cause The pilot's encounter with settling with power resulting in a loss of control. A contributing factor was the high density altitude. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, takeoff - initial climb - weather condition - high density altitude (contributing factor) - settling with power - encountered, pilot in command (cause) - aircraft control - not maintained, pilot in command (cause) - In flight collision with object, descent - uncontrolled - object - tree(s) ## Analysis The 3,807-hour helciopter pilot had just departed a private heliport on a hot day approximately 70 pounds under the certified gross weight. The pilot stated that the take-off was normal and the helicopter climbed slowly. He then increased the climb rate with a slight rearward cyclic movement. The helicopter responded by initially climbing then it immediately began to descend. During the descent, the pilot attempted to dump the chemical load, but reported that the dump doors failed to operate until his fourth try. Shortly thereafter, the main rotor blades struck trees and the helicopter descended to the ground and came to rest in an upright position. Examination of the helicopter and the dump valves revealed no mechanical deficiencies. Interpolation of the published Hover Ceiling in Ground Effect performance chart revealed that the helicopter was within the performance envelope. According to the Federal Aviation Administration (FAA) Rotorcraft Flying Handbook, pages 11-5 to 11-7, Vortex Ring State (Settling with Power), "Vortex ring state describes an areodynamic condition where a helicopter may be in a vertical descent with up to maximum power applied, and little, or no cyclic authority. The term 'settling with power' comes from the fact that the helicopter keeps settling even though full engine power is applied." The investigator-in-charge (IIC) calculated the density altitude at 3,155 feet. ## Factual narrative On August 24, 2004, about 1430 central daylight time, a Bell BH212 twin-engine helicopter, N181W, was substantially damaged during loss of control shortly after departure, approximately five miles south of Umpire, Arkansas. The commercial pilot, the sole occupant, sustained minor injuries. The helicopter was registered to and operated by Weyerhaeuser Company of SeaTac, Washington. Visual meteorological conditions prevailed, and a flight plan was not filed for the local 14 Code of Federal Regulations Part 137 agricultural flight. In a written statement, the 3,807-hour pilot reported that while spraying, his "Satloc" spray navigation system computer "crashed." He returned to the heliport, landed, and after rebooting the "Satloc" system, was able to recover his spray data. While at the heliport, the helicopter was fueled for a total of 600 pounds, and chemical mix was added for a total of 392 gallons. The helicopter departed approximately 70 pounds under it's certified gross weight, which was 11,200 pounds. The pilot reported, "the take-off was normal with speed building normally and the helicopter climbing slowly." He then increased the climb rate with "slight" rearward cyclic movement. The helicopter responded by initially climbing then "immediately" it began to descend. During the descent, the pilot attempted to dump the chemical load, but reported that the dump doors failed to operate until his fourth try. Shortly thereafter, the main rotor blades struck trees and the helicopter descended to the ground and came to rest in an upright position. A Federal Aviation Administration (FAA) aviation safety inspector performed an on-scene examination of the helicopter. He reported that the helicopter came to rest in heavily wooded terrain and sustained structural damage. The four chemical dump valves were examined by the FAA inspector and the operator's lead mechanic. The examination revealed no mechanical deficiencies with the valves. Interpolation of the published Hover Ceiling In-Ground Effect performance chart revealed that the helicopter was within the performance envelope. At 1453 central daylight time, the weather observation facility at Helms Sevier County Airport (DEQ), De Queens, Arkansas, which is located approximately 20 miles southwest of the accident site, reported wind variable at six knots, visibility 10 statute miles, few clouds at 4,600 feet, temperature 91 degrees Fahrenheit, dew point 73 degrees Fahrenheit, and a barometric pressure setting of 29.86 inches of Mercury. The investigator-in-charge (IIC) calculated the density altitude at 3,155 feet. According to the Federal Aviation Administration (FAA) Rotorcraft Flying Handbook, pages 11-5 to 11-7, Vortex Ring State (Settling with Power), "Vortex ring state describes an areodynamic condition where a helicopter may be in a vertical descent with up to maximum power applied, and little, or no cyclic authority. The term 'settling with power' comes from the fact that the helicopter keeps settling even though full engine power is applied. In a normal out-of-ground effect-hover, the helicopter is able to remain stationary by propelling a large mass of air down through the main rotor. Some of the air is recirculated near the tips of the blades, curling up from the bottom of the rotor system and rejoining the air entering the rotor from the top. However, when the helicopter begins to descend vertically, it settles into its own downwash, which greatly enlarges the tip vortices. In this vortex ring state, most of the power developed by the engine is wasted in accelerating the air in a doughnut pattern around the rotor. In addition, the helicopter may descend at a rate that exceeds the normal downward induced-flow rate of the inner blade sections. As a result, the airflow of the inner blade sections is upward relative to the disc. This produces a secondary vortex ring in addition to the normal tip-vortices. The secondary vortex ring is generated about the point on the blade where the airfoil changes from up to down. The result is an unsteady turbulent flow over a large area of the disc. Rotor efficiency is lost even though power is still being supplied from the engine." ## Aircraft - Registration: [N181W](https://openairdocs.org/deregistered/N181W-2011-06-16), registration cancelled 2011-06-16, S/N 35058, built 1992 (OpenAirDocs) - Reported make and model: Bell 212 - Registry model: [Bell 212](https://openairdocs.org/model/bell-212) (registry code 1181420) (OpenAirDocs) - Registry engine: [Pratt & Whitney PT6T-3B](https://openairdocs.org/engine/pratt-whitney-pt6t-3b) (registry code 51522, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 35058 - Airframe hours: 5551.4 - Engines: Pratt & Whitney Canada PT6T-3B 900 horsepower turbo shaft; Pratt & Whitney Canada PT6T-3B 900 horsepower turbo shaft - Damage: Substantial damage - Flight: Aerial application, Part 137 - Registered owner: Weyerhaeuser Company - Airworthiness certificate: Special, Restricted (Special) - Last inspection: 100 hour, August 13, 2004, 20.5 hours before - Departed: Wickes, AR - Airport: DEQ, J Lynn Helms Sevier County Air ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 48; injuries: minor; commercial; medical: class 2, valid medical--no waivers/lim.; last flight review May 13, 2003; seat: right; flight hours: 3,807 total, 324 in this make and model, 3,753 as pilot in command, 70 in the last 90 days, 22 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: variable at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 91 °F, dew point 73 °F - Altimeter: 29.86 inHg - Observed at: KDEQ, 21 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 20040824022869A](https://openairdocs.org/incident/20040824022869A), Aug 24, 2004: Bell 212, Dequeen, AR, Substantial damage. (-23) On August 24, 2004, about 1430 CDT a Bell 212 twin engine helicopter, N181W, was substantially damaged during loss of control shortly after departure,… 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.