# NTSB WPR13CA424: Robinson R44 - II, N190SH, Flagstaff, AZ, September 25, 2013 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Data collection · Final report - Date: September 25, 2013, 09:30 local (16:30 UTC) - Place: Flagstaff, AZ - Coordinates: 35.368331, -111.855834 - Nearby events: https://openairdocs.org/map.md?lat=35.3683&lon=-111.8558&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-flare/touchdown: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490) - Highest injury: Minor injuries - Injuries: 3 minor, 1 uninjured - Status: Completed, report November 19, 2013 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: FAA - NTSB case key (mKey): 88128 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR13CA424 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/88128/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=88128 - Page: https://openairdocs.org/ntsb/WPR13CA424 ## Probable cause The pilot's failure to maintain rotor rpm while landing in a gusty wind at a high density altitude. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Action: lack of action](https://openairdocs.org/ntsb-findings/02041030): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Robinson Helicopter R44 II, 6 cases](https://openairdocs.org/ntsb-findings/02041030/cases.md?model=7640122), [All aircraft, 792 cases](https://openairdocs.org/ntsb-findings/02041030/cases.md) - [Temp/humidity/pressure: high density altitude](https://openairdocs.org/ntsb-findings/03031020): Environmental issues › Conditions/weather/phenomena · Effect on operation; cases with it: [Robinson Helicopter R44 II, 11 cases](https://openairdocs.org/ntsb-findings/03031020/cases.md?model=7640122), [All aircraft, 278 cases](https://openairdocs.org/ntsb-findings/03031020/cases.md) - [Wind: gusts](https://openairdocs.org/ntsb-findings/03034045): Environmental issues › Conditions/weather/phenomena · Effect on operation; 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) - [Performance/control parameters: prop/rotor parameters](https://openairdocs.org/ntsb-findings/01062052): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (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) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-flare/touchdown: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490) (defining event); cases with it: [Robinson Helicopter R44 II, 16 cases](https://openairdocs.org/ntsb-events/490/sequence.md?model=7640122), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md) ## Analysis The pilot reported that he was landing the helicopter in a bowl-shaped meadow surrounded by mountains and trees. While circling the landing zone to determine the surface wind and descending, about 20 feet above ground level, the helicopter encountered a wind gust. The low rotor horn sounded and the pilot regained rpm, but another wind gust from behind again resulted in a loss of rotor rpm. The pilot said he was too low to recover, so he performed a run-on landing. The helicopter struck an earthen berm and rolled onto its left side, which resulted in substantial damage to the fuselage and tail boom. The elevation at the accident site was 8,411 feet; the density altitude was calculated to have been 10,059 feet. The pilot reported no preimpact mechanical malfunctions or failures with the helicopter that would have precluded normal operation. ## Factual narrative The pilot reported that he was landing the helicopter in a bowl-shaped meadow surrounded by mountains and trees. While circling the landing zone to determine the surface winds and descending, about 20 feet above ground level, the helicopter encountered a wind gust. The low rotor horn sounded and the pilot regained rpm, but another wind gust from behind again resulted in a loss of rotor rpm. The pilot said he was too low to recover, so he performed a run-on landing. The helicopter struck an earthen berm and rolled onto its left side, which resulted in substantial damage to the fuselage and tail boom. The elevation at the accident site was 8,411 feet; the density altitude was calculated to have been 10,059 feet. The pilot reported no preimpact mechanical malfunctions or failures with the helicopter that would have precluded normal operation. ## Aircraft - Registration: [N190SH](https://openairdocs.org/deregistered/N190SH-2016-10-11), registration cancelled 2016-10-11, S/N 11694 (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: [Lycoming IO-540-AE1A5](https://openairdocs.org/engine/lycoming-io-540-ae1a5) (registry code 41899, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 11694 - Year built: 2007 - Engines: Lycoming IO-540 245 horsepower reciprocating - Damage: Substantial damage - Flight: Part 135 - Operator: Atherton Aviation LLC, doing business as Phoenix Helicopter Services - Registered owner: Eric A. Spitzer LLC - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, August 8, 2013 - Departed: SDL, Scottsdale, AZ - Destination: Flagstaff, AZ ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 47; injuries: none; flight instructor, commercial; instrument ratings: helicopter; medical: class 2, without waivers/limitations; last flight review October 15, 2012; seat: right; restraint: 3-point; flight hours: 1,160 total, 607 in this make and model, 1,025 as pilot in command, 124 in the last 90 days, 40 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 220° at 18 knots, gusting 29 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 55 °F, dew point 36 °F - Altimeter: 30.02 inHg - Turbulence: Moderate - Observed at: FLG, 16 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 20130925022489A](https://openairdocs.org/incident/20130925022489A), Sep 25, 2013: Robinson Helicopter Company R44 II, Substantial damage. During approach to landing off airport in gusting wind conditions, N190SH experienced a hard landing and roll over. According to the pilot, the winds were… ## Docket (1 files) The files NTSB released with the investigation on November 6, 2013, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=88128. 973 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 973 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40402375&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.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.