2020 Quarter 4

The Magazine of Helicopter Association International

Ensure Fuel Purity with Soak Testing
Walter Chartrand 2020 Q4

The performance and safety of your aircraft depend on this procedure.

At my firm, Aviation Marketing Services, we’re often asked about soak testing, which is used to verify the purity of aviation fuel.

If you’re responsible for—or depend on—fuel in your work, you likely know how important it is to perform a soak test after completing new construction or major repairs to tanks or piping. This applies to both fuel storage systems and servicing vehicles. Afterward, a laboratory evaluation of the fuel samples used in the soak test can detect any potential contaminants—from solvents used in coatings and linings, welding flux, preservative oils (corrosion inhibitors), valve grease, and other debris—that could compromise the performance and safety of the fuel.

Because soak testing is such an important step in purchasing fuel, any acquisition or modification contracts for new fuel systems or servicing vehicles should include a clause that requires the manufacturer or contractor to provide evidence that a proper soak test has been performed. The clause should also require that the test results verify the fuel meets the appropriate ASTM International specifications.

Let’s review how to conduct a soak test and the various lab tests involved.

Fuel Systems, Storage Tanks, and Related Equipment

A soak test consists of filling a fuel system (stainless steel, aluminum, epoxy lined, or rubber bladder) with an adequate volume of the appropriate-grade fuel and, after following the recommended recirculation procedures, allowing it to soak for a period of time recommended by ASTM or the specific fuel supplier. Before putting the fuel in the system, be sure to retain a sample to serve as a control batch should testing reveal ­off-specification product.

By following the stringent requirements of Energy Institute (EI) Standard 1541, Requirements for Internal Protective Coating Systems Used in Aviation Fuel Handling Systems, you’ll dramatically reduce the risk of fuel contamination. Adherence to this industry standard ensures that the proper coating materials were correctly applied and allowed to fully cure as recommended by the manufacturer, and that storage tanks (including piping, pumps, valves, meters, filter vessels, and so on) are filled to the normal level and the fuel recirculated completely at least once and allowed to soak for a minimum of four days and a maximum of seven.

At the end of the designated soak period, obtain a 1 gallon sample from the new or repaired system and send it off for laboratory evaluation. The best location from which to obtain a sample is the low-point drain. Remember to displace an adequate volume in the sampling piping to ensure a truly representative sample of the tank bottom.

Fuel-Servicing Vehicles and Hoses

All fuel-servicing vehicles with tanks and piping made of aluminum or stainless steel should have the appropriate fuel circulated throughout the system. Fueling vehicles (whether new, repaired, or those that have undergone an extended period out of service) should be filled to the normal level and the fuel recirculated completely at least once and allowed to soak for at least an hour. You may obtain 1 gallon representative samples of fuel from any combination of multiple low-point drains and combine them into a single sample.

For proper soak testing, every fueler loading hose and every aircraft fueling hose must meet industry standard EI 1529/IOS (International Organization for Standardization) 1825 for hoses and assemblies. The hose must initially be filled completely with the appropriate fuel and allowed to soak for at least eight hours. The fuel in the hose must then be disposed of properly and the hose refilled.

To verify the absence of any manufacturing residue, you must perform an appearance check of the fuel for discoloration. The fuel should then be recirculated in an amount equaling at least twice the volume of the hose, back into storage, upstream of filtration. Follow up with a hose-end nozzle strainer inspection to confirm the absence of any particulate contamination.

Lab Testing of Avgas and Jet Fuels

In the case of avgas 100LL (aviation gasoline 100 low lead), the critical aspects of contamination are interfacial tension (how well water separates out from the fuel) and gum contamination, which leads to engine anomalies. The tests that should be performed on avgas 100LL are:

  • ASTM D4176, appearance
  • ASTM D381, gum content
  • ASTM D1094, water reaction
  • ASTM D2887, simulated distillation (this test is more sensitive to residue and chemical contamination than the standard test for distillation, ASTM D86).
    The tests for aviation turbine fuels (also known as jet fuels) are the same as those for avgas 100LL, with the addition of the following:
  • ASTM D156, Saybolt color test
  • ASTM D3948, MSEP (microseparometer analysis, for water separation)
  • ASTM D2624, electrical conductivity
  • ASTM D3241, jet fuel thermal oxidation test (JFTOT)
  • ASTM D56, flash point.

The JFTOT is notable because it reveals any change in volatility along with oxidation characteristics and evaluates insoluble and soluble materials that form deposits in the engine.

Correct Sampling

Fuel sample preparation, handling, and ­follow-through are all key to successfully testing aviation fuel. If a jet fuel sample is drawn through sample points that incorporate metals such as cadmium, brass, or copper, the JFTOT results may fail. Similarly, using galvanized piping (zinc) in avgas 100LL could alter the lab results.

Finally, make sure the sampling point is clean and flushed before taking a sample. Accumulated solid particulate matter or any free water should be removed, and final fuel samples should be clear and bright. Use a 1 gallon, approved epoxy-lined sampling container, and flush and triple-rinse it with the fuel to be sampled and tested. 

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Recent Accidents & Incidents
ROTOR Staff 2020 Q4

The rotorcraft accidents and incidents listed below occurred from Jul. 1 to Sep. 30, 2020. The accident details shown are ­preliminary ­information, subject to change, and may contain ­errors. All ­information was obtained through the official websites included below, where you can learn more details about each event.

Australia – Australian Transport Safety Bureau (ATSB):

Britain – Air Accident Investigation Branch (AAIB):

Canada – Transportation Safety Board of Canada (TSBC):

New Zealand – Transport Accident Investigation Commission of New Zealand (TAIC):

United States – National Transportation Safety Board (NTSB):

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The Civil Industry Responds: One Team’s Story
Dan Reed 2020 Q4

Two pilots and a mechanic discover “what they could do” to help a devastated city.

As American Eurocopter (now Airbus Helicopters North America) pilots Bruce Webb and Frank Kanauka approached New Orleans early in the afternoon of Aug. 29, 2005, they fully expected to encounter a bit of chaos.

The two pilots, along with mechanic Bob Hernandez, had been dispatched by then–American Eurocopter President Marc Paganini with two helicopters, some cash (they assumed, correctly, that the devastated city would be off the grid and unable to process credit cards), and orders to “see what they could do” to help after what was then the worst hurricane in US history. But nothing could have prepared them for the next week.

“They didn’t know what to do with us,” Webb recalls, when he and Kanauka arrived. The two had landed their aircraft at the Superdome, and Webb had gone in search of the person in charge of the powerless (and therefore dark, hot, and ridiculously humid) indoor stadium holding tens of thousands of storm refugees.

Finally, Webb found the person in charge: a general (Webb never found out his name or service branch), who asked him, “Who are you working for?” To which Webb could only reply, “I guess you.” And so, for the next seven days Webb and his small EC120 and Kanauka, flying a larger EC135, volunteered as first responders.

At first, they and Hernandez, who came along to care for their aircraft and to manage logistics, formed one of the few civilian helicopter teams in the storm zone. But by the time the trio headed back to their Texas headquarters (leaving their helicopters behind to be flown by replacement teams), more than 400 helicopters, including more than 50 operated by civilian companies and individuals, were filling the skies over the 200-mile-wide storm zone. 

“The No. 1 thing I remember was Omaha 44 and Omaha 45. If you ask someone if they were flying at Katrina, and those words don’t mean something to them, then they weren’t there,” Webb says.

“Omaha 44 and Omaha 45 were the military aircraft that controlled your ability to enter the game, so to speak,” Webb explains. FAA operations were effectively offline for a couple of weeks, so early on after the storm passed, two military planes assumed overwatch duties, doing their best to control access to the skies over New Orleans and to keep the 600 or more helicopters and fixed-wing aircraft supporting the relief efforts from bumping into one another.

On their way into New Orleans, Webb says, “Frank and I topped off at Houma,” a New Orleans suburb just across the Mississippi River, where they also left Hernandez to find a place for them to stay and to set up a makeshift helicopter support operation at the local municipal airport. Once they started working for the general, they both began shuttling refugees with medical issues northwest to the campus of Louisiana State University in Baton Rouge, where a medical triage unit had been set up.

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Helicopter Events
ROTOR Staff 2020 Q4


HAI Virtual Aerial Firefighting Conference
Helicopter Association International
Learn more at rotor.org.

NOV. 26
Young Eagle Build and Fly Program
Experimental Aircraft Association
Hilo, Hawaii, USA
Learn more at eaa.org.

NBAA GO Virtual Business Aviation Convention & Exhibition (VBACE)
National Business Aviation Association
Learn more at nbaa.org.

European Rotors: The VTOL Show and Safety Conference
General Aviation Manufacturers Association
Learn more at gama.aero.

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Mark Bathrick, Director, Office of Aviation Services, US Department of the Interior
Jen Boyer 2020 Q4

DOI UAS have conducted nearly 1,800 flights supporting wildland fire operations this year.

As the incredibly intense and destructive 2020 wildfire season begins to wind down, HAI got the chance to ask Mark Bathrick, the director of the Office of Aviation Services for the US Department of the Interior (DOI), how the season went and what next year may hold.

ROTOR: This fire season was certainly one for the books. How were DOI helicopters and unmanned aircraft systems (UAS) assets used and how did they make the most impact?

Bathrick: DOI is committed to deploying all resources and technology to protect human health and safety. The department continues using the drone fleet during wildfire response operations. So far this year and despite challenges associated with COVID-19, DOI has conducted fuel management treatments on nearly 1 million acres, putting us ahead of our 10-year average.

Commercially contracted helicopters continued to play a vital role in wildland firefighting in 2020. A critical part of the annual preparation for the fire year is the inspection of aircraft for proper equipment and conditions and the training and evaluation of pilots prior to the contract start.

Working closely with our industry and interagency partners, the Office of Aviation Services (OAS) developed COVID-19 sensitive travel and inspection risk assessments and protocols that enabled us to exceed fire-year readiness requirements while also mitigating the risk of COVID-19 to our employees, commercial vendors, interagency partners, and the communities we visited to perform the inspections.

Our UAS continue to be used across the country in support of wildland fire operations.

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Working in Longline Operations
Christine DeJoy 2020 Q4

Longline work is a special niche of the vertical takeoff and landing (VTOL) industry, one that requires precision and intricate teamwork.

1 DON’T rely on the horizon for reference when flying longline.

In most helicopter flights, the pilot faces forward, looking out the windscreen at the nose of the aircraft to determine spatial positioning. But in external-load operations, which typically use lines of 100 to 250 feet that hang below the ship, it’s critical to look out the door of the helicopter and down—a practice even experienced pilots find challenging, says Cody Barton, chief pilot for Columbia Helicopters. “Using vertical reference is the toughest thing about longline to get used to,” he says. “It can frustrate a pilot who’s new to the sector. It really gives you humility.”

2 DO practice, practice, practice.

The key to becoming adept at longline work, say experts, isn’t so much the aircraft you train in but the amount of time you put into it. “It takes about 20 hours of flight time for a pilot with no longline experience to get to a point where you can safely fly a basic longline op,” says Andre Hutchings, director of operations at external-load training company Volo Mission (VM). In VM’s in-person classes, participants practice with various line lengths—50 feet versus 200 feet, for example—to solidify their skills. And in the ground portion of the course, they learn to appreciate the perspective of the ground crew, who must complete their work with helicopters hovering over their heads.

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Lazy T Ranch's Airbus AS350 B3e
Mark Bennett 2020 Q4

The Lazy T Ranch is several thousand acres of pasture, hayfields, rolling hills, and dramatic canyons 10 miles southeast of Ten Sleep, Wyoming, as the crow flies. Or, in this case, as the Airbus AS350 B3e flies. The ranch uses the helicopter to monitor fences and outbuildings, locate cattle, and haul equipment and supplies with a newly acquired hook that can also carry a Bambi Bucket, in case wildfire strikes.

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