Saturday, May 30, 2020

Wrong Fuel: Aero Commander 500S Shrike, N909AK; accident occurred May 28, 2020 near Aniak Airport (PANI), Alaska

Aviation Accident Factual Report - National Transportation Safety Board 

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 
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
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)

ANCHORAGE, Alaska (KTUU) - A Division of Forestry plane with four people onboard crashed shortly after takeoff in the Western Alaska community of Aniak Thursday, a Forestry spokesperson said.

Gov. Mike Dunleavy made the first public announcement of the incident shortly after 5 p.m. during his third online Town Hall meeting.

"The report that we have is all survived, (with) bumps and bruises," Dunleavy said.

Tim Mowry, with the Alaska Division of Forestry, said he had just learned of the incident when reached minutes later. Mowry said the pilot and three forestry staff on board did not suffer life-threatening injuries, but he did not know to what extent they were injured.

According to an Alaska State Troopers dispatch, the plane was a state-owned Aero Commander 500S Shrike. The pilot, Mark Jordan and three other passengers were all Medevaced to Anchorage with non-life threatening injuries.

NTSB Region Chief Clint Johnson says the crash happened at about 3:43 p.m. The plane came to rest in a body of water. The Aniak airport's runway sits nestled between slight bends in the Kuskokwim River and a slough of the Aniak River. Other small bodies of water are located near Aniak's airport as well.

Photos from Aniak resident Dave Mattson show the yellow State of Alaska plane resting in what appears to be a shallow body of water. Mattson, who owns an automotive store near the airport, was at the community's barge landing when he heard the crash from half a mile away.

"It's a miracle," Mattson said. "I don't see how anyone [survived this]."

By the time he had gotten to the site of the accident, troopers had responded and the passengers were already receiving care.

There is not a staffed fire in the region, Mowry said. He was still gathering more information about the flight and the incident.


  1. Could be another misfuel where Jet-A was added instead of 100LL. Crashed shortly after refueling and taking off, diesel fuel and oil reported in the water.

  2. I am at a loss as to why GA aircraft manufacturers and aviation fuel companies do not get with the FAA and mandate a required manufacturer spout and tank receptacle size for AVGAS vs. Jet-A so these things don't happen (and even if that is not the case here, it still happens). Similar to what automotive manufacturers have done for decades with oil companies at the gas pumps with diesel vs. gas.

    1. Jet-A nozzles were made into duck-bill "Hoover nozzle" shape years ago, but sometimes the fueler angles the end to get the Jet-A into the smaller 100LL filler opening. N326CW is an example:

  3. Never depart without checking the color of your fuel.

    1. A paper blot test might also be a good idea if it was just a top off. Take a look at color for a 50/50 mix experiment with photos here:

  4. Better yet, stay with the plane and supervise the refueling.

    1. Particularly for Aerostar and Commander/Shrike aircraft, with the known misfuel event histories.

      And it is unreal that any fuel tech would have so little interest in aviation that the obvious differences of piston and turboprop engines would not be immediately recognized (cylinder cooling fins visible and the lack of giant side-discharge exhausts). And of course, markings on fill ports.

  5. "Damage: UNKNOWN"

    When you find your airplane broken into pieces and resting in a pond it tells me the damage is pretty severe. I don't believe the damage is unknown.

    1. The front fell off and the back fell off. Recovery photo:

    2. Excellent photo. It'll take a lot of duct tape to get that bird back in the air.

    3. It was a nice Commander. I had taken a picture of it back in September 2019. My dad flew this aircraft reguarly. He wasn't flying it that day.

  6. I had a 680F Commander with piston engines. It had "Turbo" emblems on the side of the cowlings. One can see that causing confusing with the line guys.

  7. No preliminary report yet, they missed the two-week goal for that. Fuel sample after recovery would be of interest even if nothing more could be checked.

  8. NTSB 30 June preliminary report says it was fueled with Jet A, as suspected here in comments.

  9. Fuel port was clearly marked:

  10. From the accident report:
    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.

    Maybe the fueler meant "Do you want a PRIEST? Because I just fueled you like a jet."


Note: Only a member of this blog may post a comment.