# NTSB GAA19CA344: Bell UH 1H, N4085L, Bethel, AK, June 6, 2019 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: June 6, 2019, 14:00 local (22:00 UTC) - Place: Bethel, AK - Coordinates: 60.792221, -161.764724 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=60.7922&lon=-161.7647&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report November 6, 2019 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 99641 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA19CA344 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/99641/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=99641 - Page: https://openairdocs.org/ntsb/GAA19CA344 ## Probable cause The pilot's improper fuel planning, which resulted in fuel exhaustion and a total loss of engine power, and his improper landing flare during a forced autorotation, which resulted in a hard landing. Contributing to the accident were the inoperative fuel gauge, which was not accurately calibrated, and the pilot’s reliance on the gauge. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Planning/preparation: fuel planning](https://openairdocs.org/ntsb-findings/02061030): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Bell UH-1H, 1 case](https://openairdocs.org/ntsb-findings/02061030/cases.md?model=1181407), [All aircraft, 719 cases](https://openairdocs.org/ntsb-findings/02061030/cases.md) - [Fluids: fuel](https://openairdocs.org/ntsb-findings/01071010): Aircraft › Fluids/misc hardware · Fluid level (probable cause); cases with it: [Bell UH-1H, 2 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md?model=1181407), [All aircraft, 1,695 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md) - [Performance/control parameters: landing flare](https://openairdocs.org/ntsb-findings/01062041): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Bell UH-1H, 2 cases](https://openairdocs.org/ntsb-findings/01062041/cases.md?model=1181407), [All aircraft, 1,285 cases](https://openairdocs.org/ntsb-findings/01062041/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Bell UH-1H, 9 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=1181407), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Fuel system: fuel indication system](https://openairdocs.org/ntsb-findings/01022840): Aircraft › Aircraft systems · Incorrect service/maintenance (probable cause); cases with it: [Bell UH-1H, 1 case](https://openairdocs.org/ntsb-findings/01022840/cases.md?model=1181407), [All aircraft, 30 cases](https://openairdocs.org/ntsb-findings/01022840/cases.md) - [Use of equip/info: use of equip/system](https://openairdocs.org/ntsb-findings/02063015): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Bell UH-1H, 1 case](https://openairdocs.org/ntsb-findings/02063015/cases.md?model=1181407), [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md) - [Fluids: fuel](https://openairdocs.org/ntsb-findings/01071010): Aircraft › Fluids/misc hardware · Inadequate inspection; cases with it: [Bell UH-1H, 2 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md?model=1181407), [All aircraft, 1,695 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering: Fuel exhaustion](https://openairdocs.org/ntsb-events/192); cases with it: [Bell UH-1H, 1 case](https://openairdocs.org/ntsb-events/192/sequence.md?model=1181407), [All aircraft, 804 cases](https://openairdocs.org/ntsb-events/192/sequence.md) - [Maneuvering: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Bell UH-1H, 3 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=1181407), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Autorotation: Hard landing](https://openairdocs.org/ntsb-events/092); cases with it: [Bell UH-1H, 2 cases](https://openairdocs.org/ntsb-events/092/sequence.md?model=1181407), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) ## Analysis The pilot reported that, before departure, he was told the helicopter was topped off with fuel for the multistop flight. He added that he did not verify the fuel quantity but that, when he departed for the last leg about 60 miles from the destination airport, the fuel gauge showed just below 600 lbs of fuel, and he decided to fly at 120 knots with a tailwind. He added that, about 3 miles from the destination airport, the engine lost power. He performed an autorotation, but the helicopter landed hard. The helicopter sustained substantial damage to the tailboom and transmission mounts. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. The pilot reported that, after landing, the fuel quantity gauge showed that there was about 225 lbs of fuel remaining and that the 20-minute fuel light, which did not illuminate during the flight, illuminated once on the ground. He estimated that the helicopter's fuel burn was about 75 to 80 gallons per hour (gph). The chief pilot, who was also the helicopter's owner, reported that he had refueled the helicopter on uneven terrain before the flight. He filled the tank to the bottom of the filler cap on the left side, which he estimated was about 10 to 15 gallons less than the total fuel capacity of the 210-gallon tank. He estimated that the helicopter burned about 90 gph. He added that there were no open mechanical squawks on the helicopter and that he was not aware of any mechanical issues. The Federal Aviation Administrator inspector who examined the helicopter at the accident site reported that the fuel quantity gauge had been serviced and calibrated earlier in the year but continued to indicate that fuel was onboard even after the helicopter ran out of fuel. The 20-minute low fuel light appeared to be functioning normally. ## Factual narrative The pilot reported that, prior to departure, he was told the helicopter was topped off with fuel for the multi-stop flight. He added that he did not verify the fuel quantity. During the last leg, he departed about 60 miles from the destination airport with just below 600 pounds of fuel and he decided to fly at 120 knots with a tailwind. He added that about 3 miles from the destination airport, the engine lost power. He performed an autorotation but landed hard. The pilot reported that after landing, the fuel quantity gauge read about 225 pounds of fuel remaining and that the 20-minute fuel light which did not illuminate during the flight, illuminated once on the ground. The pilot was unsure if anyone had verified the fuel quantity remaining after landing, but they added about 50 gallons of fuel and continued to the destination airport. He estimated that the helicopter's fuel burn was about 75 to 80 gallons/hour. The chief pilot and owner reported that he had refueled the helicopter, which was on uneven terrain, before the flight. He filled the tank to the bottom of the filler cap on the left side, which he estimated was about 10 to 15 gallons less than total fuel capacity of 210 gallon tank. He estimated that the helicopter burned about 90 gallons/hour. He added that there were no open mechanical squawks on the helicopter and that he was not aware of any mechanical issues. The Federal Aviation Administrator inspector, who examined the helicopter at the accident site, reported that the fuel quantity gauge had been serviced and calibrated earlier in the year, but continued to indicate fuel after the helicopter ran out of fuel. The 20-minute low fuel light appeared to be functioning normally. The helicopter sustained substantial damage to the tailboom and transmission mounts. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. ## Aircraft - Registration: [N4085L](https://openairdocs.org/deregistered/N4085L-2020-08-21), registration cancelled 2020-08-21, S/N 68-15655, built 1968 (OpenAirDocs) - Reported make and model: Bell UH 1H (No Series) - Registry model: [Bell UH-1H](https://openairdocs.org/model/bell-uh-1h) (registry code 1181407) (OpenAirDocs) - Registry engine: [Lycoming T53-L-13](https://openairdocs.org/engine/lycoming-t53-l-13) (registry code 41551, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 68-15655 - Year built: 1968 - Engines: Lycoming T53-13 1400 horsepower turbo shaft - Damage: Substantial damage - Flight: External load, Part 133 - Operator: Yukon Helicopters Inc - Registered owner: Yukon Helicopters Inc - Airworthiness certificate: Special, Restricted (Special) - Departed: None, Bethel, AK - Destination: BET, Bethel, AK - Flight plan: Company VFR - Equipment: Handheld GPS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 50; injuries: none; commercial; medical: class 2, without waivers/limitations; last flight review May 12, 2019; seat: left; restraint: 3-point; flight hours: 5,275 total, 2,500 in this make and model, 4,795 as pilot in command, 78 in the last 90 days, 62 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 310° at 9 knots - Visibility: 10 statute miles - Lowest ceiling: 1,600 ft broken - Temperature: 52 °F, dew point 43 °F - Altimeter: 30.23 inHg - Observed at: PABE, 2 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 20190606005969A](https://openairdocs.org/incident/20190606005969A), Jun 6, 2019: Bell UH-1H, Bethel, AK, Substantial damage. Aircraft experienced engine failure due to fuel exhaustion. ## Other investigations on N4085L (1) 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 DEN99LA160](https://openairdocs.org/ntsb/DEN99LA160), Sep 6, 1999: Bell UH-1H (N4085L), Silverton, CO, substantial damage. Probable cause: The total loss of engine power for undetermined reasons. A factor was the lack of suitable terrain for a forced landing. ## Docket (5 files) The files NTSB released with the investigation on August 9, 2019, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=99641. 4.1 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 3.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40475004&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Record of Conversation - Pilot (item 2, .PDF, 123 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40475005&FileExtension=.PDF&FileName=Record%20of%20Conversation%20-%20Pilot-Master.PDF - Record of Conversation - Chief Pilot/Owner (item 3, .PDF, 68 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40475006&FileExtension=.PDF&FileName=Record%20of%20Conversation%20-%20Chief%20Pilot%2FOwner-Master.PDF - Record of Conversation - FAA Inspector (item 4, .PDF, 68 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40475007&FileExtension=.PDF&FileName=Record%20of%20Conversation%20-%20FAA%20Inspector-Master.PDF - Accident Photos (item 5, .PDF, 335 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40475008&FileExtension=.PDF&FileName=Accident%20Photos-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.