Misfuelling Accidents

Misfuelling aircraft with kerosene based Jet A-1 rather than Aviation Gasoline (AVGAS) continues to be a source of accidents.

PA31 15 Sept 2015 Manitoba

The Canadian Transportation Safety Board (TSB) has recently released an update on the 15 September 2015 accident involving twin engined Keystone Air Service Piper PA31-350 Navajo C-FXLO at Thompson, Manitoba.  Shortly after takeoff the aircraft experienced a malfunction and the crew attempted to land back at Thompson. The aircraft impacted terrain less than 1 nautical mile from the airport. All 8 persons on board survived.

PA31 C-F (Credit: TSB)

PA-31 C-FXLO (Credit: TSB)

The TSB say:

The ongoing investigation has confirmed that the aircraft received an incorrect type of fuel in Thompson, Manitoba, prior to departing for Winnipeg. The twin piston-engine aircraft requires aviation gasoline (AvGas), but was re-fueled with turbine engine fuel (Jet A1). The aircraft was destroyed by impact with trees and terrain; however, the aircraft cabin section remained largely intact. Almost all of the fuel was dispersed throughout the crash site from ruptured fuel cells but a sufficient quantity remained to obtain samples. There was no post-impact fire.

The occupants sustained varying serious injuries but were able to assist each other and exit the aircraft.

UPDATE 10 November 2015: Transport Canada has now suspended the operator’s AOC (for a third time since 2002). UPDATE 8 September 2016: The TSB release their report.

The refuelling technician, who had been working for the fuelling company for a just over a month, and had no prior aviation experience, had fuelled another aircraft with Jet A1 before the Keystone aircraft arrived and drove the Jet A1 truck to where the PA-31 had parked.

The aircraft commander had intended to relay the fuel requirements to the technician, but the Co-Pilot, who was escorting passengers, had noticed that the fuel technician was having trouble with the  fuel filler openings. The Co-Pilot assisted the technician and asked for required fuel.  The Captain overhead this conversation and so did not talk to the refueller.

Neither pilot noticed that the truck was a jet fuel truck. The technician did not spot the aircraft placard specifying aviation gasoline.

Aircraft Fuel Placard (Credit: TSB)

When the technician couldn’t get the flared fuel filler nozzle to fit, he switched to a narrower nozzle, defeating a defence to prevent Jet A1 being used on a piston engined aircraft, but was sometimes required on aircraft that needed Jet A1.

Fuel Nozzles (Credit: TSB)

Prior to departure, the Captain returned to the fuel providers office to collect the fuel slip but it was unoccupied  The crew then performed an abbreviated check before taking off.

TSB say:

The Esso fuel dealer at Thompson Airport was Mara-Tech Aviation Fuels Ltd, which operated the Imperial Oil owned facility and equipment under an aviation dealer agreement. In addition to its day-to-day operation of the facility, Mara-Tech was responsible for staffing the facility and training the employees. Training materials were supplied by Imperial and consisted of a series of CDs or VHS tapes whose content was organized into modules. Each module was accompanied by a corresponding multiple-choice quiz.

Aviation dealer agreements require that fuel dealers adhere to Imperial’s operating standards and procedures. Under the aviation dealer agreement, fuel dealers have a licence to use Imperial brand trademarks, such as Esso and Esso Aviation, in marketing their businesses.

The [fuel technician's] training consisted of reading the Imperial training material, viewing the CDs, and completing the corresponding multiple-choice quizzes. Additional certifications, such as Airside Vehicle Operator’s Permit and Transportation of Dangerous Goods, were administered by the manager at Mara-Tech’s Thompson facility.

The training was completed in 5 days and was followed by on-the-job training (riding along with the manager to gain experience fuelling aircraft). The fuel technician carried out the first unassisted fuelling on 22 August 2015.

PA46 22 February 2015 Washington

The US National Transportation Safety Board (NTSB) is investigating a 22 February 2015 fatal accident involving single engined Piper PA46-350P Malibu Mirage C-GVZW in Spokane, Washington state. The aircraft was destroyed and the pilot killed, during the attempted emergency landing when it struck a railroad track.  In their preliminary report the NTSB say:

…the fuel tanks ruptured during the accident sequence, and there was a strong smell of Jet [A-1] fuel present. The FAA inspector obtained the fuelling log from Western Aviation… the fuel log indicated that the accident airplane had been refuelled with 52 gallons of Jet [A-1] fuel prior to takeoff.

C421 27 August 2014 New Mexico

The NTSB is also investigating a 27 August 2014 fatal accident involving twin engined Elite Medical Transport / Amigos Aviation Cessna 421C Golden Eagle N51RX at Las Cruces (LRU), New Mexico when it impacted the ground shortly after takeoff.  All four people on board the air ambulance flight died.

Air Ambulance Accident Site Near Las Cruces (Credit: via KOAT)

Air Ambulance Accident Site Near Las Cruces (Credit: via KOAT)

According to the NTSB:

The airplane arrived LRU about 1834 to pickup a patient for a flight to PHX. The pilot was still seated in the cockpit when he gave the line service technician a verbal order for a total of forty gallons of fuel. The line service technician drove the fuel truck to the front of the airplane and refueled the airplane putting 20 gallons in each wing. The pilot then assisted the line service technician with replacing both fuel caps. They both walked into the office and the pilot signed the machine printed fuel ticket. …there was an immediate postimpact fire which consumed much of the airplane. Investigators who arrived at the scene on the day following the accident reported detecting the smell of jet fuel. A postaccident review of refueling records and interviews with line service technicians showed that the airplane had been misfuelled with 40 gallons of Jet A fuel instead of the required 100LL aviation gasoline.

Past History of Fuelling Accidents

In their report on the PA-31 accident the TSB comment:

…FAA AC 20-105B states, “Reciprocating [gasoline] engines that burn Jet A at high power settings suffer detonations, rapid loss of power, and high cylinder head temperatures, quickly followed by complete engine failure.”

Following a series of misfuelling events in the 1980s, the aviation industry took initiatives to prevent further occurrences. Some aircraft manufacturers issued service bulletins, and made kits available, to reduce the size of fuel filler openings on aircraft that required AVGAS. The FAA and TC subsequently issued airworthiness directives that made the service bulletins mandatory.

As a result, flared spouts that would not fit into the smaller AVGAS filler openings were introduced on fuelling equipment. Fuel suppliers placed additional labelling and placarding on fuelling equipment. [Aircraft Fuel Handling Technician] training programs were introduced, and more detailed operations manuals were developed. FAA AC 20-105B and bulletins issued by some aircraft manufacturers encouraged operators to remove the words “Turbo” and “Turbo-charged” from the cowlings of turbo-charged aircraft.

In 1993, size standards for fuel filler openings were incorporated in Federal Aviation Regulations (FARs) Part 23 Airworthiness Standards: Normal, Utility, Acrobatic and Commuter Category Airplanes. The standards specified that airplanes with engines that require gasoline must have fuel filler openings no larger than 2.36 inches; airplanes with turbine engines must have fuel filler openings no smaller than 2.95 inches; and each fuel filler opening must be marked with the fuel type and minimum grade.

Certain airplanes and rotorcraft powered by turbine engines cannot be fuelled using the Jet-A1 flared spout. Some aircraft manufactured prior to the current standard have fuel filler openings that do not meet the current dimension requirements. Aircraft that have been modified by replacing the reciprocating engine with a turbine engine sometimes retain their original fuel filler openings. The angle and location of the fuel filler openings on some aircraft make the use of the Jet-A1 flared spout impractical. Consequently, many Jet-A1 fuel trucks and stationary fuelling cabinets are equipped with a reduced-diameter spout that can be temporarily installed in place of the Jet-A1 flared spout.

A review of the TSB database revealed [see below] that, since 1980, there have been 21 recorded instances [in Canada] in which jet fuel was delivered to an aircraft instead of AVGAS, 10 of which have occurred since 2000. Of those 21 events, 17 occurred at an aerodrome, 3 were related to refuelling from drums, and 1 occurred at a float-plane dock. These misfuelling events resulted in 8 crashes and 11 forced landings. There was 1 fatality and a number of injuries, some severe. In 2 cases, the misfuelling was detected prior to departure of the aircraft.

TSB File # Inv Class Flown Fixed-wing Rotary-wing
A80Q0056 Nil Britten-Norman Islander YES X
A83O4077 Nil Piper PA-31 YES X
A88Q0058 C5 Piper PA-28 YES X
A92W0078 C5 Rockwell Aero Commander 685 NO X
A93O0287 C5 Canadair CL215 NO X
A97A0131 5 Piper PA-31 YES X
A97A0132 5 Hughes 269C YES X
A97C0140 5 Beech 60 Duke YES X
A98C0114 5 Piper PA-31-350 YES X
A98O0292 5 Schweizer 269C (300C) YES X
A99F0064 5 Piper PA-31 YES X
A00O0181 5 Cessna 414 YES X
A02P0089 5 Piper PA23-250 YES X
A05P0063 5 De Havilland DHC-2 YES X
A07Q0230 5 Piper PA-31 YES X
A07W0228 5 Piper PA-31-350 YES X
A10C0123 3 Rockwell Aero Commander 500S YES X
A11Q0036 3 3 Robinson R44 IIs YES X
A15F0029 5 Piper PA-46-350P YES X
A15C0134 3 Piper PA-31-350 YES X
A16Q0059 5 Piper PA-31 YES X


Total have issued a useful guide on avoiding errors in fuelling.  It includes a number of deliberate steps to trap any human errors or misunderstandings consistent with our past article: Professor James Reason’s 12 Principles of Error Management Some airfield fuel suppliers, such as at Lydd in Kent, refuse to supply fuel unless a clear fuel type decal is displayed. Anecdotally ‘turbo’ markings on aircraft (indicating turbo-charged piston engines) have been mistaken in the past as indicating gas turbine engines.

UPDATE 29 March 2016: The NTSB have issued safety alerts on fuelling, one for pilots and the other for refuellers.

UPDATE 25 June 2020: Japanese Jetstar Boeing 787 GEnx-1B Engine Biocide Serious Incident

UPDATE 19 July 2020: Wrong fuel added before crash of Alaska forestry plane that injured pilot and 3 firefighters, NTSB says

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