The National Transportation Safety Board did not travel to the scene of this accident.
Additional Participating Entity:
Federal Aviation Administration / Flight Standards District Office; Anchorage, Alaska
Investigation Docket - National Transportation Safety Board:
State of Alaska operated by Division of Forestry
Location: Aniak, Alaska
Accident Number: ANC20LA050
Date and Time: May 28, 2020, 16:00 Local
Registration: N909AK
Aircraft: Rockwell 500
Aircraft Damage: Substantial
Defining Event: Wrong fuel
Injuries: 4 Serious
Flight Conducted Under: Public aircraft
Factual Information
On May 28, 2020, about 1600 Alaska daylight time, an Aero Commander 500S airplane, N909AK sustained substantial damage when it was involved in an accident near Aniak, Alaska. The pilot and three passengers sustained serious injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 public aircraft flight.
The airplane was owned by the State of Alaska and operated by the Division of Forestry.
According to the pilot, after arriving in Aniak, he had the local fuel vendor's ground service personnel refuel the airplane. He then signed the fuel receipt, and he returned to the airplane's cockpit to complete some paperwork before departure. Once the paperwork was complete, he then loaded his passengers, started the airplane's engines, and taxied to Runway 29 for departure.
The pilot said that shortly after takeoff, and during initial climb, he initially noticed what he thought was mechanical turbulence followed by a reduction in climb performance, and the airplane's engines began to lose power. Unable to maintain altitude and while descending about 400 ft per minute, he selected an area of shallow water covered terrain as an off-airport landing site. The airplane sustained substantial damage during the landing.
The fueler reported that he was unfamiliar with the airplane, so he queried the pilot as to where he should attach the grounding strap and the location of the fuel filler port. Before starting to refuel the airplane, he asked the pilot "do you want Prist with your Jet" to which the pilot responded that he did not. After completing the refueling process, he returned to his truck, wrote "Jet A" in the meter readings section of the prepared receipt, and presented it to the pilot for his signature. The pilot signed the receipt and was provided a copy. The fueler stated that he later added "no Prist" to his copy of the receipt, and that he did not see a fuel placard near the fueling port.
A postaccident examination revealed that the reciprocating engine airplane had been inadvertently serviced with Jet A fuel. A slightly degraded placard near the fuel port on the top of the wing stated, in part: "FUEL 100/100LL MINIMUM GRADE AVIATION GASOLINE ONLY CAPACITY 159.6 US GALLONS."
Pilot Information
Certificate: Airline transport; Commercial; Flight instructor
Age: 53, Male
Airplane Rating(s): Single-engine land; Single-engine sea; Multi-engine land
Seat Occupied: Left
Other Aircraft Rating(s): None
Restraint Used:
Instrument Rating(s): Airplane
Second Pilot Present: No
Instructor Rating(s): Airplane single-engine; Instrument airplane
Toxicology Performed: No
Medical Certification: Class 2 With waivers/limitations
Last FAA Medical Exam: September 5, 2019
Occupational Pilot: Yes
Last Flight Review or Equivalent:
Flight Time: 4869 hours (Total, all aircraft), 30 hours (Total, this make and model), 4003 hours (Pilot In Command, all aircraft), 40 hours (Last 90 days, all aircraft), 40 hours (Last 30 days, all aircraft), 4.5 hours (Last 24 hours, all aircraft)
Aircraft and Owner/Operator Information
Aircraft Make: Rockwell
Registration: N909AK
Model/Series: 500S
Aircraft Category: Airplane
Year of Manufacture: 1975
Amateur Built:
Airworthiness Certificate: Normal
Serial Number: 3232
Landing Gear Type: Retractable - Tricycle
Seats:
Date/Type of Last Inspection: March 5, 2020 Annual Certified
Max Gross Wt.: 6748 lbs
Time Since Last Inspection:
Engines: 2 Reciprocating
Airframe Total Time: 6966.4 Hrs as of last inspection
Engine Manufacturer: Lycoming
ELT: C126 installed, not activated
Engine Model/Series: IO-540 SER
Registered Owner:
Rated Power: 325 Horsepower
Operator:
Operating Certificate(s) Held: None
Meteorological Information and Flight Plan
Conditions at Accident Site: Visual (VMC)
Condition of Light: Day
Observation Facility, Elevation:
Distance from Accident Site:
Observation Time: 23:56 Local
Direction from Accident Site:
Lowest Cloud Condition: Few / 6500 ft AGL
Visibility: 10 miles
Lowest Ceiling: Overcast / 12000 ft AGL
Visibility (RVR):
Wind Speed/Gusts: /
Turbulence Type Forecast/Actual: /
Wind Direction:
Turbulence Severity Forecast/Actual: /
Altimeter Setting: 30.15 inches Hg
Temperature/Dew Point: 15°C / 2°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: Aniak, AK
Type of Flight Plan Filed: Company VFR
Destination: Soldotna, AK
Type of Clearance: None
Departure Time:
Type of Airspace: Class E
Wreckage and Impact Information
Crew Injuries: 1 Serious
Aircraft Damage: Substantial
Passenger Injuries: 3 Serious
Aircraft Fire: None
Ground Injuries:
Aircraft Explosion: None
Total Injuries: 4 Serious
Latitude, Longitude: 61.581665,-159.54306(est)
