National Transportation Safety Board
Aviation Accident Final Report

 

 

Location:

Bethel, AK

Accident Number:

GAA19CA344

Date & Time:

06/06/2019, 1400 AKD

Registration:

N4085L

Aircraft:

Bell UH 1H

Aircraft Damage:

Substantial

Defining Event:

Loss of engine power (total)

Injuries:

2 None

Flight Conducted Under:

Part 133: Rotorcraft Ext. Load

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.

 

Probable Cause and Findings

The National Transportation Safety Board determines the probable cause(s) of this accident to be:
 

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

Aircraft

Fuel - Fluid level (Cause)

Landing flare - Not attained/maintained (Cause)

Fuel indication system - Incorrect service/maintenance (Factor)

Fuel - Inadequate inspection

Personnel issues

Fuel planning - Pilot (Cause)

Aircraft control - Pilot (Cause)

Use of equip/system - Pilot (Factor)

Factual Information

History of Flight

Maneuvering

Fuel exhaustion

Loss of engine power (total) (Defining event)

Autorotation

Hard landing

 

 

Pilot Information

Certificate:

Commercial

Age:

50, Male

Airplane Rating(s):

None

Seat Occupied:

Left

Other Aircraft Rating(s):

Helicopter

Restraint Used:

 

Instrument Rating(s):

None

Second Pilot Present:

No

Instructor Rating(s):

None

Toxicology Performed:

No

Medical Certification:

Class 2 Without Waivers/Limitations

Last FAA Medical Exam:

01/07/2019

Occupational Pilot:

Yes

Last Flight Review or Equivalent:

05/12/2019

Flight Time:

(Estimated) 5275 hours (Total, all aircraft), 2500 hours (Total, this make and model), 4795 hours (Pilot In Command, all aircraft), 78 hours (Last 90 days, all aircraft), 62 hours (Last 30 days, all aircraft)

 

 

Aircraft and Owner/Operator Information

Aircraft Make:

Bell

Registration:

N4085L

Model/Series:

UH 1H No Series

Aircraft Category:

Helicopter

Year of Manufacture:

1968

Amateur Built:

No

Airworthiness Certificate:

Restricted

Serial Number:

68-15655

Landing Gear Type:

Skid

Seats:

2

Date/Type of Last Inspection:

 Unknown

Certified Max Gross Wt.:

9500 lbs

Time Since Last Inspection:

 

Engines:

1 Turbo Shaft

Airframe Total Time:

 

Engine Manufacturer:

Lycoming

ELT:

Installed, not activated

Engine Model/Series:

T53-13

Registered Owner:

Yukon Helicopters Inc

Rated Power:

1400 hp

Operator:

Yukon Helicopters Inc

Operating Certificate(s) Held:

Agricultural Aircraft (137); Rotorcraft External Load (133)

 

Meteorological Information and Flight Plan

Conditions at Accident Site:

Visual Conditions

Condition of Light:

Day

Observation Facility, Elevation:

PABE, 102 ft msl

Distance from Accident Site:

2 Nautical Miles

Observation Time:

2153 UTC

Direction from Accident Site:

257°

Lowest Cloud Condition:

 

Visibility

10 Miles

Lowest Ceiling:

Broken / 1600 ft agl

Visibility (RVR):

 

Wind Speed/Gusts:

9 knots /

Turbulence Type Forecast/Actual:

None / None

Wind Direction:

310°

Turbulence Severity Forecast/Actual:

N/A / N/A

Altimeter Setting:

30.24 inches Hg

Temperature/Dew Point:

11°C / 6°C

Precipitation and Obscuration:

No Obscuration; No Precipitation

Departure Point:

Bethel, AK (None)

Type of Flight Plan Filed:

Company VFR

Destination:

Bethel, AK (BET)

Type of Clearance:

None

Departure Time:

 AKD

Type of Airspace:

Class D

 

 

Wreckage and Impact Information

Crew Injuries:

1 None

Aircraft Damage:

Substantial

Passenger Injuries:

1 None

Aircraft Fire:

None

Ground Injuries:

N/A

Aircraft Explosion:

None

Total Injuries:

2 None

Latitude, Longitude:

60.792222, -161.764722 (est)

 


 


Administrative Information

Investigator In Charge (IIC):

Kathryn R Benhoff

Report Date:

11/06/2019

Additional Participating Persons:

Paula Huckleberry; FAA; Anchorage, AK

Publish Date:

11/06/2019

Note:

This accident report documents the factual circumstances of this accident as described to the NTSB.

Investigation Docket:

http://dms.ntsb.gov/pubdms/search/dockList.cfm?mKey=99641