# NTSB ERA11IA436: Bell 206, N484AE, Relience, TN, August 1, 2011 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: August 1, 2011, 18:18 local (22:18 UTC) - Place: Relience, TN - Coordinates: 35.233333, -84.45417 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=35.2333&lon=-84.4542&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Controlled flight into terr/obj (CFIT)](https://openairdocs.org/ntsb-events/120) - Highest injury: No injuries - Injuries: 4 uninjured - Status: Completed, report April 24, 2012 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 81355 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA11IA436 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/81355/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=81355 - Page: https://openairdocs.org/ntsb/ERA11IA436 ## Probable cause Inadvertent contact with wires due to the lack of visual cues regarding their presence and the low angle of the sun, which was directly in the takeoff path. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Object/animal/substance: wire](https://openairdocs.org/ntsb-findings/03022032): Environmental issues › Physical environment · Awareness of condition (probable cause); cases with it: [Bell Helicopter Textron Canada 206L-4, 1 case](https://openairdocs.org/ntsb-findings/03022032/cases.md?model=1181455), [All aircraft, 588 cases](https://openairdocs.org/ntsb-findings/03022032/cases.md) - [Light condition: glare](https://openairdocs.org/ntsb-findings/03036030): Environmental issues › Conditions/weather/phenomena · Not specified; cases with it: [Bell Helicopter Textron Canada 206L-4, 1 case](https://openairdocs.org/ntsb-findings/03036030/cases.md?model=1181455), [All aircraft, 109 cases](https://openairdocs.org/ntsb-findings/03036030/cases.md) - [Light condition: bright light](https://openairdocs.org/ntsb-findings/03036010): Environmental issues › Conditions/weather/phenomena · Not specified; cases with it: [Bell Helicopter Textron Canada 206L-4, 1 case](https://openairdocs.org/ntsb-findings/03036010/cases.md?model=1181455), [All aircraft, 28 cases](https://openairdocs.org/ntsb-findings/03036010/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Controlled flight into terr/obj (CFIT)](https://openairdocs.org/ntsb-events/120) (defining event); cases with it: [Bell Helicopter Textron Canada 206L-4, 1 case](https://openairdocs.org/ntsb-events/120/sequence.md?model=1181455), [All aircraft, 1,074 cases](https://openairdocs.org/ntsb-events/120/sequence.md) ## Analysis Before landing, the pilot performed a high and low reconnaissance of the area and received a briefing of the obstacles by the landing zone. The crew was advised of wires along the road north of the field and large rolls of hay spaced intermittently across the field. The pilot then landed the helicopter in a field and picked up a patient who had been involved in a motor vehicle accident. Given the weight of the helicopter and power available, the pilot elected to perform an airspeed-over-altitude takeoff on a westerly departure path along the long axis of the landing zone. The departure path was signaled to the landing zone commander, who issued an approval for the takeoff. During the initial takeoff climb, the helicopter struck wires and returned to the field for landing. After the incident, a closer inspection of the takeoff path revealed that a three-strand group of wires crossed the west side of the field perpendicular to the takeoff path. When viewed from the point of departure, the wires appeared to emanate from the thick, tall tree lines that bordered both sides of the landing zone, and were superimposed against a background of dense woods. There were no additional visual cues (poles, towers, or transformers) available that could be associated with the wires. Additionally, at the time of the accident, the sun was directly in the takeoff path and 30 degrees above the horizon. The bright sunlight and glare conditions likely reduced the ability of ground crew and the flight crew to discern wire obstacles. ## Factual narrative HISTORY OF FLIGHT On August 1, 2011, about 1818 eastern daylight time, a Bell 206 L4 helicopter, N484AE, operated by Air Evac EMS, Inc., sustained minor damage from a wire strike during takeoff in Reliance, Tennessee. The certificated commercial pilot, two crewmembers and one patient were not injured. Visual meteorological conditions prevailed, and a company flight plan was filed for the flight that departed a farm field in wooded, hilly terrain. The medical evacuation flight was conducted under the provisions of 14 CFR Part 135, and destined for Erlanger Medical Center Heliport (0TN8), Chattanooga, Tennessee. In a written statement, the pilot stated that the purpose of the flight was to pick up a patient that had been involved in a motor vehicle accident. The landing zone (LZ) was a large field where he performed an approach after performing a "high and low recon" of the area, and receiving a briefing of the obstacles by the "LZ command" that was established by the local fire department. The crew was advised of wires along the road north of the field, and large rolls of hay spaced intermittently across the field. After he determined the weight of the helicopter and power available, the pilot decided on an "airspeed over altitude" takeoff. The pilot chose a westerly departure path because the field offered a "long, open area with down-sloping terrain." The departure path was signaled to the LZ commander, who issued approval for the takeoff through a firefighter. The pilot initiated the takeoff, and when the helicopter reached 50 feet and 40 knots, the pilot adjusted the flight controls for a 60-knot climb. About that time, the pilot heard a loud "thud" and saw scuff marks on the windscreen that alerted him to the wire strike. He announced the emergency to his crew, and completed a precautionary landing back to the field. Written statements provided by both crewmembers were consistent with the pilot's. On August 2, 2011, a Federal Aviation Administration (FAA) aviation safety inspector visited the site, and photographed the area. Damage to the helicopter was limited to the windscreen, and no major structural damage was noted. Scratches in the paint and marks on the upper and lower Wire Strike Protection System (WSPS) were consistent with a wire strike. The inspector observed that a three-strand group of wires crossed the west side of the field perpendicular to the takeoff path. When viewed from the point of departure, the wires appeared out of the thick, tall tree lines that bordered both sides of the LZ, and were superimposed against a background of dense woods. There were no additional visual cues (poles, towers, or transformers) available that could be associated with the wires. PERSONNEL INFORMATION The pilot held a commercial pilot certificate with ratings for rotorcraft helicopter and instrument helicopter. He reported 2,173 total hours of flight experience, of which 116 were in the incident helicopter make and model. His most recent FAAsecond-class medical certificate was issued on June 1, 2011. AIRCRAFT INFORMATION According to FAA records, the helicopter was manufactured in 2010. The most recent inspection in the helicopter Approved Aircraft Inspection Program (AAIP) was completed July 27, 2011, at 564 total aircraft hours. METEOROLOGICAL INFORMATION At 1853, the weather conditions reported at Lovell Field, Chattanooga, Tennessee, located approximately xx miles xx of the incident site, included few clouds at 6,500 feet, visibility 10 miles, temperature 36 degrees C, dew point 15 degrees C, and an altimeter setting of 29.93 inches of mercury. The wind was from 120 degrees at 6 knots. The calculated density altitude at the time of the incident was 3,318 feet. According to the U.S. Naval Observatory, at the time of the incident the azimuth of the sun was about 273 degrees east of north, and the sun was positioned approximately 28 degrees above the horizon. ## Aircraft - Registration: [N484AE](https://openairdocs.org/aircraft/N484AE), registered now, S/N 52411, built 2010 (OpenAirDocs) - Reported make and model: BELL 206 (L4) - Registry model: [Bell Helicopter Textron Canada 206L-4](https://openairdocs.org/model/bell-helicopter-textron-canada-206l-4) (registry code 1181455) (OpenAirDocs) - Registry engine: [Rolls-Royce 250-C30P](https://openairdocs.org/engine/rolls-royce-250-c30p) (registry code 54013, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 52411 - Airframe hours: 564 - Engines: Rolls-Royce 250-C30P turbo shaft - Damage: Minor damage - Flight: Part 135 - Operator: Air Evac Ems Inc - Registered owner: Wells Fargo Bank Northwest NA Trustee - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, July 27, 2011, 9 hours before - Departed: Relience, TN - Destination: 0TN8, Chattanooga, TN - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 30; injuries: none; commercial; instrument ratings: helicopter; medical: class 2, without waivers/limitations; last flight review November 25, 2010; seat: right; flight hours: 2,173 total, 116 in this make and model, 1,223 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: 20° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 97 °F, dew point 59 °F - Altimeter: 29.93 inHg - Observed at: KCHA, 42 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). - [Incident 20110801016359I](https://openairdocs.org/incident/20110801016359I), Aug 1, 2011: Bell Helicopter 206L-4, Reliance, TN, Minor damage. This was a scene flight from a field not designated as a heliport. The fire department had cleared the landing zone and was standing by with the ground… ## Docket (8 files) The files NTSB released with the investigation on March 21, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=81355. 3.8 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 663 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40351854&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Crew Member Statments (item 2, .PDF, 66 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40351855&FileExtension=.PDF&FileName=Crew%20Member%20Statments-Master.PDF - FAA Inspector Statement (item 3, .PDF, 86 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40364789&FileExtension=.PDF&FileName=FAA%20Inspector%20Statement-Master.PDF - Air Evac Operations Procedures (item 4, .PDF, 700 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40351872&FileExtension=.PDF&FileName=Air%20Evac%20Operations%20Procedures-Master.PDF - Chattenooga (CHA) Meteorological Conditions (item 5, .PDF, 63 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40352013&FileExtension=.PDF&FileName=Chattenooga%20(CHA)%20Meteorological%20Conditions-Master.PDF - Chattanooga Area Sunlight Conditions (item 6, .PDF, 59 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40352018&FileExtension=.PDF&FileName=Chattanooga%20Area%20Sunlight%20Conditions-Master.PDF - Photo 1: View of Wires Behind Helicopter (item 7, .PDF, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40364693&FileExtension=.PDF&FileName=Photo%201%3A%20View%20of%20Wires%20Behind%20Helicopter-Master.PDF - Photo 2: View of Wires Suspended Through Trees (item 8, .PDF, 784 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40364694&FileExtension=.PDF&FileName=Photo%202%3A%20View%20of%20Wires%20Suspended%20Through%20Trees-Master.PDF 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.