# NTSB CEN13LA507: Robinson Helicopter R44 II, N744KA, Clayton, NM, August 26, 2013 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: August 26, 2013, 15:25 local (21:25 UTC) - Place: Clayton, NM - Coordinates: 36.597499, -103.274719 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=36.5975&lon=-103.2747&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: Minor injuries - Injuries: 3 minor, 1 uninjured - Status: Completed, report December 5, 2013 - Report: Approved by Office Director - NTSB office: Central Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 87868 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN13LA507 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/87868/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=87868 - Page: https://openairdocs.org/ntsb/CEN13LA507 ## Probable cause The pilot's loss of vertical control after the helicopter encountered a gusty tailwind while maneuvering at a low altitude and near the helicopter's maximum gross weight. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Robinson Helicopter R44 II, 99 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=7640122), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Wind: gusts](https://openairdocs.org/ntsb-findings/03034045): Environmental issues › Conditions/weather/phenomena · Ability to respond/compensate (probable cause); cases with it: [Robinson Helicopter R44 II, 10 cases](https://openairdocs.org/ntsb-findings/03034045/cases.md?model=7640122), [All aircraft, 1,199 cases](https://openairdocs.org/ntsb-findings/03034045/cases.md) - [Aircraft capability: climb capability](https://openairdocs.org/ntsb-findings/01061010): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [Robinson Helicopter R44 II, 5 cases](https://openairdocs.org/ntsb-findings/01061010/cases.md?model=7640122), [All aircraft, 183 cases](https://openairdocs.org/ntsb-findings/01061010/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-low-alt flying: Low altitude operation/event](https://openairdocs.org/ntsb-events/220); cases with it: [Robinson Helicopter R44 II, 45 cases](https://openairdocs.org/ntsb-events/220/sequence.md?model=7640122), [All aircraft, 780 cases](https://openairdocs.org/ntsb-events/220/sequence.md) - [Maneuvering-low-alt flying: Other weather encounter](https://openairdocs.org/ntsb-events/400); cases with it: [Robinson Helicopter R44 II, 14 cases](https://openairdocs.org/ntsb-events/400/sequence.md?model=7640122), [All aircraft, 1,127 cases](https://openairdocs.org/ntsb-events/400/sequence.md) - [Maneuvering-low-alt flying: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Robinson Helicopter R44 II, 74 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=7640122), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Maneuvering-low-alt flying: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Robinson Helicopter R44 II, 95 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=7640122), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that 25-30 minutes into the aerial photography flight, the helicopter began to settle (descend under power) while established in a left turn from an easterly heading about 100 feet above the ground. The pilot increased collective control, but the helicopter continued to descend as it approached two sets of power lines. He stated that with full engine power, the helicopter was able to clear both sets of power lines; however, the low rotor speed warning horn sounded as the helicopter crossed over the second set of power lines. The pilot briefly reduced the collective control to regain rotor speed, but, as the helicopter approached the ground, he increased collective control in another attempt to arrest the descent. The pilot stated that the helicopter impacted terrain in a manner similar to a hard landing, bounced, and rolled over onto its left side. The pilot reported there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation. In his statement, the pilot indicated the likelihood that the helicopter's encounter with a southerly wind gust during the left turn from an easterly heading sufficiently reduced the amount of available lift from the main rotor to allow the helicopter to descend with full engine power and collective control. A nearby weather station reported gusty wind conditions from the south, with peak speeds of 32 knots. A southerly wind gust during a left turn from an easterly heading would have resulted in a tailwind condition and an associated loss of available lift from the main rotor. The pilot estimated the helicopter's weight at the time of the accident was about 9 pounds below the helicopter's certificated maximum gross weight. The pilot's maneuvering of the helicopter at a low altitude, while at nearly maximum gross weight, reduced his ability to regain vertical control before the helicopter encountered the power lines and terrain. ## Factual narrative On August 26, 2013, at 1525 mountain daylight time, a Robinson Helicopter Company model R44 II helicopter, N744KA, was substantially damaged while maneuvering near Clayton, New Mexico. The commercial pilot was not injured. The 3 passengers sustained minor injuries. The airplane was registered to and operated by King Ag Leasing, under the provisions of 14 Code of Federal Regulations Part 91, without a flight plan. Day visual meteorological conditions prevailed for the personal flight, which departed Clayton Municipal Airpark (KCAO), Clayton, New Mexico, at 1450.The pilot reported that the purpose of the flight was to conduct aerial photography of a nearby location where the passengers had recently hunted. The pilot reported that he was concerned with the density altitude at the departure airport, so he initially loaded only two passengers and completed a takeoff and landing. The helicopter reportedly had no performance issues during the short flight and a third passenger subsequently boarded the helicopter. After an uneventful takeoff, the flight proceeded north of the airport toward the location to be photographed. The pilot reported that 25-30 minutes into the flight, the helicopter began to settle (descend under power) while established in a left turn from an easterly heading about 100 feet above the ground. The pilot increased collective control, but the helicopter continued to descend as it approached two sets of power lines. He stated that with full engine power the helicopter was able to clear both sets of power lines; however, the low rotor speed warning horn sounded as the helicopter crossed over the second set of power lines. The pilot briefly reduced the collective control to regain rotor speed, but as the helicopter approached the ground he increased collective control in another attempt to arrest the descent. The pilot stated that the helicopter impacted terrain in a manner similar to a hard landing, bounced, and rolled over onto its left side. The pilot reported there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation. The pilot stated that the helicopter likely encountered a southerly wind gust during the left turn from an easterly heading, which reduced the amount of available lift from the main rotor enough to allow the helicopter to descend with full engine power and collective control. Additionally, the pilot estimated the helicopter's weight at the time of the accident was about 2,391 pounds. The helicopter's certificated maximum gross weight was 2,400 pounds. The nearest aviation weather reporting station was located at Clayton Municipal Airpark (KCAO), Clayton, New Mexico, about 12 miles south of the accident site. At 1555, the KCAO automated surface observing system reported: wind from 160 degrees at 17 knots, gusting 32 knots; visibility 10 miles; broken ceiling at 8,000 feet above ground level; temperature 31 degrees Celsius; dew point 11 degrees Celsius;and an altimeter setting of 30.22 inches of mercury. At 1553, a peak wind was reported from 170 degrees at 32 knots. The weather station elevation was 4,964 feet mean sea level. The calculated density altitude was 7,721 feet. ## Aircraft - Registration: [N744KA](https://openairdocs.org/aircraft/N744KA), registered now, S/N 13168 (OpenAirDocs) - Reported make and model: Robinson Helicopter Company R44 II - Registry model: [Robinson Helicopter R44 II](https://openairdocs.org/model/robinson-helicopter-r44-ii) (registry code 7640122) (OpenAirDocs) - Registry engine: [Lycoming IO-540-AE1A5](https://openairdocs.org/engine/lycoming-io-540-ae1a5) (registry code 41899, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 13168 - Airframe hours: 129 - Engines: Lycoming IO-540-AE1A5 245 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: King Ag Leasing - Registered owner: King Ag Leasing - Airworthiness certificate: Standard, Normal - Last inspection: Annual, August 6, 2012, 129 hours before - Departed: KCAO, Clayton, NM - Destination: KCAO, Clayton, NM ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 60; injuries: none; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review March 31, 2012; seat: right; flight hours: 16,825 total, 606 in this make and model, 16,506 as pilot in command, 225 in the last 90 days, 62 in the last 30 days, 9 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 160° at 17 knots, gusting 32 - Visibility: 10 statute miles - Lowest ceiling: 8,000 ft broken - Temperature: 88 °F, dew point 52 °F - Altimeter: 30.21 inHg - Observed at: KCAO, 12 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 20130826019949A](https://openairdocs.org/incident/20130826019949A), Aug 26, 2013: Robinson Helicopter Company R44 II, Clayton, NM, Destroyed. On August 26, 2013, at approximately 1540 MDT, N744KA, a Robinson Helicopter Company model R-44 ii, registered to king ag leasing, inc., was on a local flight… ## Docket (3 files) The files NTSB released with the investigation on September 25, 2013, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=87868. 415 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 255 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40400260&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Weather Information (item 2, .PDF, 96 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40400261&FileExtension=.PDF&FileName=Weather%20Information-Master.PDF - Density Altitude Calculation (item 3, .PDF, 64 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40400262&FileExtension=.PDF&FileName=Density%20Altitude%20Calculation-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.