# NTSB CEN10LA556: Robinson Helicopter R44 II, N145DM, Duluth, MN, September 17, 2010 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: September 17, 2010, 00:23 local (05:23 UTC) - Place: Duluth, MN - Coordinates: 47.008335, -92.214996 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=47.0083&lon=-92.2150&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: Minor injuries - Injuries: 1 minor - Status: Completed, report April 12, 2011 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA-Minneapolis FSDO - NTSB case key (mKey): 77387 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN10LA556 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/77387/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=77387 - Page: https://openairdocs.org/ntsb/CEN10LA556 ## Probable cause The pilot's failure to identify and arrest the helicopter's descent due to spatial disorientation. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Perception/orientation/illusion: spatial disorientation](https://openairdocs.org/ntsb-findings/02022025): Personnel issues › Psychological · Pilot (probable cause); cases with it: [Robinson Helicopter R44 II, 10 cases](https://openairdocs.org/ntsb-findings/02022025/cases.md?model=7640122), [All aircraft, 358 cases](https://openairdocs.org/ntsb-findings/02022025/cases.md) - [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) - [Light condition: dark](https://openairdocs.org/ntsb-findings/03036020): Environmental issues › Conditions/weather/phenomena · Effect on operation; cases with it: [Robinson Helicopter R44 II, 8 cases](https://openairdocs.org/ntsb-findings/03036020/cases.md?model=7640122), [All aircraft, 448 cases](https://openairdocs.org/ntsb-findings/03036020/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: [Robinson Helicopter R44 II, 12 cases](https://openairdocs.org/ntsb-events/120/sequence.md?model=7640122), [All aircraft, 1,074 cases](https://openairdocs.org/ntsb-events/120/sequence.md) ## Analysis According to the pilot, he lifted the helicopter into a hover and subsequently established a 600 foot-per-minute rate of climb at 60 knots airspeed to depart the area. As the helicopter climbed out, he reported a sinking feeling in the seat and noticed that the vertical speed indicator displayed a descent. The pilot increased the engine power but the helicopter continued to descend. The pilot could not discern his exact height above the water because of the night lighting conditions and thought that the helicopter was higher off the water than it was; as a result, he did not flare prior to impact. A witness reported that the liftoff and initial climb also appeared normal and that the helicopter appeared to be level and remain in controlled flight the entire time. A postaccident examination of the airframe and engine revealed no mechanical malfunctions or failures that would have precluded normal operation. The witness commented that the conditions were dark at the time of the accident, but there was a distinguishable horizon. The light wind reported at the time of the accident and lack of convective activity in the area is inconsistent with a downdraft or microburst condition. ## Factual narrative On September 17, 2010, about 0023 central daylight time, a Robinson R44 II helicopter, N145DM, piloted by a commercial pilot, was destroyed during an in-flight collision with the waters of Island Lake near Duluth, Minnesota. The flight was being conducted under 14 Code of Federal Regulations Part 91 without a flight plan. Night visual meteorological conditions prevailed. The pilot sustained minor injuries. The flight departed from a beach on Island Lake and was on the initial climbout at the time of the accident. The intended destination was Duluth International Airport (DLH), Duluth, Minnesota, which was located about 10 miles south of the accident site. The pilot reported that he had flown from DLH to the beach site on Island Lake in order to show the helicopter to some prospective clients. After spending several hours, he decided to return to DLH. The pilot stated that he lifted off into a hover, and subsequently established a 600 foot-per-minute rate of climb at 60 knots airspeed to depart the area. As he climbed out, he reported a "sinking feeling in the seat all of a sudden," and noticed that the vertical speed indicator "started to dip down indicating a descent." His flight instruments indicated that the helicopter was at 60 knots airspeed and in level flight; "everything checked out." He increased engine power, but was still descending. The pilot referenced the flight instruments a second time and noted that "all indications showed level and 60 [knots]." He recalled thinking that the helicopter might have encountered a "microburst of some type." He added that he could not tell the helicopter's exact height above the water because of the night lighting conditions. The helicopter hit the water at about 60 knots. The pilot commented that he thought the helicopter was still higher off the water and, as a result, did not flare prior to impact. A witness reported that the start and warm up were unremarkable. In addition, the liftoff and initial climb also appeared normal. He stated, "If the entire event took 10 seconds, only the last 2, showed concern as we could see the distance between the [helicopter's navigation] lights and the reflection in the water markedly become closer, ultimately converging." He noted that the helicopter appeared to be level and remain in controlled flight the entire time. A post accident examination of the helicopter did not reveal any anomalies consistent with a pre impact failure or malfunction. Weather conditions recorded at DLH, located about 10 miles south of the accident site, at 2355, included: Scattered clouds at 11,000 feet above ground level (agl), 10 miles visibility, and winds from 180 degrees at 4 knots. At 0055, conditions included: Broken clouds at 10,000 feet agl, 10 miles visibility, and wind from 240 degrees at 7 knots. The moon set at 0058, about 35 minutes after the accident. It was in a waxing gibbous phase, with 73 percent of the visible disk illuminated. The witness commented that the "nightwas dark, but there was a distinguishable horizon." He did not feel that the conditions were "adverse" for the pilot's return flight. The pilot informed Federal Aviation Administration (FAA) inspectors that he had executed a similar type of night departure in June; although, the night of the accident was darker. The pilot did not hold an instrument rating. However, he was reportedly working toward the rating and he had accumulated about 30 hours of instrument flight time. ## Aircraft - Registration: [N145DM](https://openairdocs.org/deregistered/N145DM-2017-05-15), registration cancelled 2017-05-15, S/N 11004, built 2005 (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 series](https://openairdocs.org/engine/lycoming-io-540-series) (registry code 41530, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 11004 - Airframe hours: 1175 - Engines: LYCOMING IO-540 SER 300 horsepower reciprocating - Damage: Destroyed - Flight: Business, Part 91 - Operator: Lake Superior Helicopters - Registered owner: Jauss Aviation Inc - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, September 3, 2010, 8 hours before - Departed: PVT, Duluth, MN - Destination: DLH, Duluth, MN - Airport: DLH, Duluth International ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 24; injuries: minor; flight instructor, commercial; medical: class 2, without waivers/limitations; last flight review May 5, 2010; seat: right; flight hours: 1,600 total, 300 in this make and model, 65 in the last 90 days ## Weather - Conditions: Visual (VMC), Night/dark - Wind: 240° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: 10,000 ft broken - Temperature: 48 °F, dew point 45 °F - Altimeter: 29.95 inHg - Observed at: DLH, 11 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 20100917046489A](https://openairdocs.org/incident/20100917046489A), Sep 17, 2010: Robinson He R44 II, Duluth, MN, Destroyed. The pilot conducted a night takeoff from a beach and initiated his climb out over water. The sky/water reference line was poor due to few ground lights,… ## Docket (2 files) The files NTSB released with the investigation on November 9, 2010, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=77387. 1.3 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40338543&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Witness Statement (item 2, .PDF, 95 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40338544&FileExtension=.PDF&FileName=Witness%20Statement-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.