# NTSB DFW08CA177: Robinson R44 II, N804DF, Canyon Lake, TX, July 5, 2008 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Data collection · Final report - Date: July 5, 2008, 16:00 local (21:00 UTC) - Place: Canyon Lake, TX - Coordinates: 29.916944, -98.305557 - Nearby events: https://openairdocs.org/map.md?lat=29.9169&lon=-98.3056&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-hover: Loss of tail rotor effectiveness](https://openairdocs.org/ntsb-events/242) - Highest injury: Minor injuries - Injuries: 1 minor, 2 uninjured - Status: Completed, report August 28, 2008 - Report: Approved by Office Director - Parties: San Antonio FSDO - NTSB case key (mKey): 68395 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DFW08CA177 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/68395/pdf - Page: https://openairdocs.org/ntsb/DFW08CA177 ## Probable cause A total loss of tail rotor effectiveness. Contributing to the accident was the pilot's improper decision to operate inside the height velocity curve. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Robinson Helicopter R44 II, 40 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=7640122), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Performance/control parameters: prop/rotor parameters](https://openairdocs.org/ntsb-findings/01062052): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [Robinson Helicopter R44 II, 17 cases](https://openairdocs.org/ntsb-findings/01062052/cases.md?model=7640122), [All aircraft, 182 cases](https://openairdocs.org/ntsb-findings/01062052/cases.md) - [Performance/control parameters](https://openairdocs.org/ntsb-findings/01062000): Aircraft › Aircraft oper/perf/capability · Not specified (probable cause); cases with it: [Robinson Helicopter R44 II, 25 cases](https://openairdocs.org/ntsb-findings/01062000/cases.md?model=7640122), [All aircraft, 1,269 cases](https://openairdocs.org/ntsb-findings/01062000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-hover: Loss of tail rotor effectiveness](https://openairdocs.org/ntsb-events/242) (defining event); cases with it: [Robinson Helicopter R44 II, 9 cases](https://openairdocs.org/ntsb-events/242/sequence.md?model=7640122), [All aircraft, 100 cases](https://openairdocs.org/ntsb-events/242/sequence.md) ## Analysis The commercial pilot was conducting a photo flight with himself and two passengers in the four seat helicopter. The helicopter had been in a zero airspeed out of ground effect hover at approximately 40 to 50 feet above the ground for about 15 seconds when the pilot applied power to begin a vertical climb. According to the pilot, he then suddenly and without warning lost directional control, the helicopter began to spin nose right, and his application of full left pedal had no effect. The pilot initiated an autorotation and the helicopter landed hard on rough rocky sloping terrain between several trees. The crash caused substantial damage to the fuselage and airframe when the left skid gear partially collapsed and penetrated into the left rear passenger cabin floor area. The upper pylon was noticeably bent and wrinkled, and both main rotor blades were damaged. An on-scene investigation by an FAA maintenance inspector confirmed continuity and no apparent damage to the flight controls. There was no post-crash fire and the pilot and front seat passenger reported no injuries, but the left rear seat passenger suffered minor injuries and had to be carried out of the aircraft. The pilot reported the surface winds were light and variable, visibility 10 statute miles with scattered clouds at 3,000 feet, a temperature of 88 degrees, and an altimeter setting of 30.01 inches of mercury. ## Factual narrative The commercial pilot was conducting a photo flight with himself and two passengers in the four seat helicopter. The helicopter had been in a zero airspeed out of ground effect hover at approximately 40 to 50 feet above the ground for about 15 seconds when the pilot applied power to begin a vertical climb. According to the pilot, he then suddenly and without warning lost directional control, the helicopter began to spin nose right, and his application of full left pedal had no effect. The pilot initiated an autorotation and the helicopter landed hard on rough rocky sloping terrain between several trees. The crash caused substantial damage to the fuselage and airframe when the left skid gear partially collapsed and penetrated into the left rear passenger cabin floor area. The upper pylon was noticeably bent and wrinkled, and both main rotor blades were damaged. An on-scene investigation by an FAA maintenance inspector confirmed continuity and no apparent damage to the flight controls. There was no post-crash fire and the pilot and front seat passenger reported no injuries, but the left rear seat passenger suffered minor injuries and had to be carried out of the aircraft. The pilot reported the surface winds were light and variable, visibility 10 statute miles with scattered clouds at 3,000 feet, a temperature of 88 degrees, and an altimeter setting of 30.01 inches of mercury. ## Aircraft - Registration: [N804DF](https://openairdocs.org/deregistered/N804DF-2019-11-04), registration cancelled 2019-11-04, S/N 11265, built 2006 (OpenAirDocs) - Reported make and model: Robinson R44 II - Registry model: [Robinson Helicopter R44 II](https://openairdocs.org/model/robinson-helicopter-r44-ii) (registry code 7640122) (OpenAirDocs) - Registry engine: [Continental IO-540 series](https://openairdocs.org/engine/continental-io-540-series) (registry code 17051, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 11265 - Airframe hours: 421 - Engines: Lycoming IO-540-AE1A5 205 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial observation, Part 91 - Operator: Helicopter Tours of Texas - Registered owner: Royal Aeronautical Services USA LLC - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, June 1, 2008 - Departed: Gruene, TX - Airport: 34TS, Canyon Lake ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 60; injuries: none; commercial; medical: class 2, with waivers/limitations; last flight review October 1, 2007; seat: right; flight hours: 731 total, 113 in this make and model, 569 as pilot in command, 49 in the last 90 days, 21 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 88 °F - Altimeter: 30.01 inHg ## 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 20080705839879A](https://openairdocs.org/incident/20080705839879A), Jul 5, 2008: Robsin R44RAVENII, Spring Branch, TX, Substantial damage. (-23) On July 5, 2008, at approximately 1600 CDT, a Robinson R44 helicopter, N804DF, sustained substantial damage when it landed hard after loss of tail rotor… ## Other investigations on N804DF (2) 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 GAA17CA165](https://openairdocs.org/ntsb/GAA17CA165), Feb 19, 2017: Robinson Helicopter R44 (N804DF), Spofford, TX, substantial damage. Probable cause: The pilot's decision to hover-taxi out of the hangar and his subsequent failure to maintain clearance from the hangar. - [NTSB GAA15CA232](https://openairdocs.org/ntsb/GAA15CA232), Jul 16, 2015: Robinson Helicopter R44 II (N804DF), Prairie Lea, TX, substantial damage. Probable cause: The pilot's failure to maintain rotor rpm, resulting in an uncontrolled descent and collision with trees. 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.