It’s Time to Eliminate Traditional Filter Monitors
Superabsorbent Polymer (SAP) is a key component in filter monitors that are in standard use across the industry to ensure fuel quality while refuelling aircraft. However, given the accumulated evidence against SAP, the industry recognises the need for new options. In fact, the industry committed to begin phasing out the use of SAP in the refuelling process.1 Immediate and decisive action is needed, even as the industry focuses on recovering from the COVID-19 pandemic.2 At a time when the industry's margin for risk is smaller than ever, is your airline doing enough to mitigate the hidden threats associated with Superabsorbent Polymer (SAP)?
Eliminating the Risks of Refuelling
Read the transcript
Read the transcript
Description:
Shell’s Global Technical & Quality Manager, Rob Midgley, walks through a presentation explaining the risk of using superabsorbent polymer in filter monitors.
Title: Eliminating the Risks of Refuelling
Duration: 6:08 minutes
[Background music plays]
Bright, uplifting music
[Animation]
A three-dimensional model of Earth rotates while white silhouettes of planes fly across the globe. The right side of the screen displays photos of Andreas Schmidt, Rob Midgley, and Vincent Begon.
[Text displays]
Flightpath
[Text displays]
This episode
Eliminating the Risks of Refuelling with Traditional Filter Monitors
[Text displays]
Vincent Begon
Commercial Airlines Manager Europe
Shell Aviation
Vincent Begon: As the world and aviation are starting to look toward recovery, Shell are hosting a series of webinar on topic which we hope may help our airlines customer during this difficult time to help clear the runway of any obstacle. We would like to get you back in the air where you belong.
[Text displays]
Rob Midgley
Global Quality & Technical Manager
Shell Aviation
Rob Midgley: We're here to learn about the background of superabsorbent polymers and how Shell has been involved in investigating flight safety related events.
[Animated model showing the path of fuel through a traditional aircraft filter]
[Text displays]
The current industry approach
[Bulleted list]
- Two-stage filter monitors remove both dirt and water from fuel.
- Removal of water is critical to safety.
- These filters use SAP, with some amount released downstream into the engines.
Rob Midgley: Most filtration going into wing at the moment is done via filter monitors. The filter is really there as a last chance safety device for fuel going onto the aircraft. We've used this for many years, probably 90% of the aircraft fuellings or more use this type of technology. But we first saw trouble with this back in 2010. It happened after an aircraft refueled in a location called Surabaya in Indonesia. On that flight, the pilot lost control of the engines. This aircraft landed very high speed on a very long runway. So we're very close to having an aircraft loss here. But for the skill of the pilots and the training of the airline itself, we might well have had. So this ended with an investigation to try and understand what happened.
Shell was asked to be involved with this investigation. We were one of the few oil companies that has technical capability to be able to test filters at full scale and full flow rates.
[Animated model showing superabsorbent polymer in the filter, then zooming in to show the superabsorbent polymer as it fills with water and expands, becoming porous]
Rob Midgley: We found that when you get super absorbent polymer wet, then it doesn't just expand and grow, but it also softens in the process. And that makes it problematic when you're looking at filters because filters are designed to hold solid particulates that don't change their form.
[Slide showing bar graph of SAP output per manufacturer tested. Text displays: Filter Monitors SAP Migration Results - After SAP-Mitigation Controls Were Put Into Place]
Rob Midgley: Unfortunately, we then start to see a series of incidents happening within the industry. There was an IATA taskforce that was set up to investigate if there was any link between the presence of superabsorbent polymer and these operational incidents. The conclusion of that work is that we have to remove superabsorbent polymer.
What does it mean for airlines?
Strictly speaking, any fuel that has super absorbent polymer in it doesn't meet the fuel specifications. It's also clear that airlines themselves are responsible for ensuring that fuel meets the specification.
[Text displays]
THE OPERATIONAL CHALLENGE: AN AIRLINE’S POINT OF VIEW
Vincent Begon: Now I'll turn it over to our special guest Andreas Schmidt from Lufthansa to give us an airline's perspective.
[Text displays]
Andreas Schmidt
Manager Jet Fuel Quality
Lufthansa
Andreas Schmidt: Fortunately, there are very rare latest investigation reports available, which indicates that SAP contamination was root causing latest events, but there was no actual data available for SAP contamination checks. So there are additional mitigation measures, as it has been said, implemented in the industry, but their effectiveness was not yet proven according to our knowledge.
So we went on setting up our own program and try to see how these mitigation measures were effective or not.
We can conclude I think that real safety issues detected and needs proper mitigation. There is no safe option available besides phasing out filter monitors and we need to act now, play our role. Change can only happen if we all start acting.
Vincent Begon: What I don't understand is why this is still an issue and that no airlines can claim SAP free fueling today. What exactly are the reasons we aren't there yet?
Rob Midgley: It's mainly because there's a large number of the airline inter plane activity is done through filter monitors. The only currently approved alternative to filter monitors is to use filter water separators. It's got a physically much bigger vessel involved with filter water separators. Most vehicles don't have the space to fit them and if they do, you're often exceeding the weight limitations of the vehicles.
So lots of the work that's happened since 2017 is focusing on a solution that fits into the existing vessels. That's where we've done quite a lot of work with Shell jet protection. I'm proud to say that Shell has been involved with developing this alongside FAUDI Aviation and over the past few years.
[Slide showing Shell Jet Protection. Text displays: Developed with FAUDI Aviation, Pending approval by JIG, Most technically mature drop-in solution, Easily fitted into the current refuelling fleet, Sensor constantly assesses fuel for presence of water, Approval anticipated at end of 2020.]
Vincent Begon: That's good to see that there are options for SAP-free fuelling being developed and I'm glad that Shell is also doing its part. Is there any recommendation that you would like to share for them to prepare for these transition for this management of change? Any big recommendation?
Rob Midgley: First of all, the data shows, so coming back to basics of what we're trying to do. The data shows that all filter monitors have the potential to emit superabsorbent polymer, even when operated correctly, and within the bulletin's limitations. So that's point number one.
There's no safe limit for super absorbent polymer within aircraft systems. So the engine equipment manufacturers will tell you that. We must move away from filter monitors. As safety is Shell's number one priority, we're taking that responsibility very seriously and we're investing heavily in this transition and accelerating it.
The second point is that encouraging others to act early, so at least form a transition plan to be SAP free. So this is where we start to need to act together as an industry to drive that aspiration forward. Solutions are appearing that don't require a filter vessel change, and they're starting to become approved. So those conversations and those plans need to be set in place of how operators are going to be removing filter monitors, what time scale, and how is that going to work.
So finally, I think you can act today by working with suppliers at the industry as a whole can be working with airlines, OEMs and suppliers to make sure that we're SAP free and send a strong message to the industry that we need to be incorporating within the decision matrix driven in fuel contracting phase of how to accelerate that transitional process. So only by helping to accelerate the industry do we move to a safer pace more quickly.
[Visual of Shell™ pecten logo]
Contact us at: SAV-Flightpath@shell.com
The views, information, or opinions expressed during this video series are solely those of the individuals involved and do not necessarily represent those of the Shell group of companies and its employees. Shell Aviation has funded the production and recording of this video to drive sustainability conversations in the aviation industry.
It's Time to Eliminate Traditional Filter Monitors and the Risks They Pose
Questions about the safety of SAP first emerged in 2010 when a passenger jet belonging to a major international airline experienced engine trouble, causing it to lose thrust control and land at twice the normal speed. Thanks to the skill and training of the aircrew, this resulted in no injuries. But the cause was a mystery. Though not involved with the fuelling of the flight, Shell Aviation was asked as an independent expert by an Aviation Regulator and the airline, to investigate the cause of the incident. The team found a possible correlation between the presence of SAP and issues with the fuel-control unit experienced during the flight.
Following a further sequence of incidents, the International Air Transport Association (IATA) convened a Special Interest Group in May 2014 to investigate whether SAP was a factor in these cases as well. Participants included representatives from airframe and engine manufacturers, fuel-filter manufacturers, airlines and airline associations, the Energy Institute, and Shell Aviation, which chaired the group.
No easy solutions
Conventional fuel monitors are designed to capture water and solids from fuel before it's used by an aircraft. They do this by employing a physical filter to catch solid particles and SAP, a material that is also used in disposable diapers, to absorb water. As the IATA investigative taskforce looked into these fuel monitors, they discovered that under certain circumstances, SAP could become saturated and swollen and leak small, gel-like material into fuel. In rare cases, this SAP material can cause significant operational issues in engines. Since 2010, a total of eight incidents have been identified as a result of SAP migration into the fuel and have resulted in issues ranging from a loss of control to in-flight engine failure.3
"We started to see other engine and aircraft types involved, [issues like] heavy surge damage, complete turbine failure, an aircraft that lost its engine on take-off. So really serious stuff," Midgley said.
Filter monitor manufacturers have confirmed it is not possible to guarantee that no SAP will pass downstream in the fuel into the engines. 4And engine manufacturers will not endorse any level of SAP in fuel as "safe." The conclusion: It's not possible to use a filter monitor that contains SAP and be 100% confident that SAP contamination will not happen and will not impact engine performance.5
"We can see from that data that even with the controls that we have in place, existing filter monitors still have the potential to release superabsorbent polymer, Midgley said. "So, when we combine that with no known lower limits (for SAP in fuel), then we must transition away from filter monitors as an industry."
While the solution of replacing filter monitors is straightforward, it is not necessarily easy. Thousands of fuelling systems worldwide employ filter-monitor technology using SAP. The only currently available existing alternative involves the use of water filter separators, which are bulky and difficult to retrofit into existing fleets. Huge challenges loom at the world's largest and busiest airports, whose high-flow hydrant operations mean that new filter water separators would need to be massive and require new vehicles to carry them.6
"The filter water separator is physically a much, much bigger, much heavier vessel. That means that most vehicles don't have the space to fit them. If they do, you're often exceeding the weight limitations of the vehicle. So instead of now changing a filter … you're also changing the vessel. You're also potentially changing the vehicle as well. So that leads into a program of very high cost and very long implementation programs," Midgley said.
In addition to the potential safety risks, the price of postponing action to replace traditional filter monitors could be high. Inaction could impose costs on airlines since engine OEMs have determined that there is no safe level of SAP. Damage determined to be a result of SAP, therefore, may not be covered by OEMs.
"Real safety issues have been detected and need proper mitigation," Andreas Schmidt, Manager of Jet Fuel Quality at Lufthansa, told the webinar. "So, there is no safe option available besides phasing out filter monitors. We need to act now, and each play our role. Change can only happen if we all start acting."
A way forward through industry collaboration
The challenge of transitioning to safer, SAP-free refuelling demanded collaboration across the industry. With this in mind, Shell Aviation and FAUDI Aviation worked together to combine their technical expertise and develop a solution that doesn't use SAP. The result is a technically mature, drop-in solution that replaces the filter monitor with a dirt-defence filter which captures dirt suspended in fuel along with a new and extremely sensitive sensor that continually scans the fuel for water contamination. This system is 100% SAP-free and is called Shell Jet Protection.
The water sensor continually assesses fuel quality and can detect 30 parts per million of water in fuel flowing at up to 7 meters per second. When you're detecting less than 30 parts per million, then it's a very small number. "To put this into context, it is the equivalent of trying to detect and count 270 people in the 9-million-person population of Greater London if they were to all run past you at once. Then that's the sort of level of granularity we're talking about. So, these sensors are quite impressive technology." Midgley said.
If water is detected – a rare occurrence – fuelling of the aircraft is shut down. It detects the water rather than using a chemical to absorb it. The solution is pending approval by the Joint Inspection Group (JIG) and should be available later in 2020.7
"We're at the position now where we're confident that that technology is robust, and the industry as a whole has been working together with field trials to make sure that it operates successfully in the field," Midgley said. "Our intention is to have no filter monitors left in Shell locations where we are under operational control by the end of this year, end of 2020."
Safety is our industry's top priority, and the science is clear: Current filter monitor solutions emit SAP, and there is no safe level of SAP in aviation fuel. By recognising this risk and working together now, the industry can transition away from filter monitors that use SAP to enable safer and more efficient operations.
Ask Shell Aviation
At Shell Aviation, we understand that while the industry is facing various challenges as a result of the pandemic, enabling and maintaining efficient and safe operations will be crucial for Aviation’s recovery.
Today, most aircraft refuellers are fitted with filter monitors that prevent water and dirt particles from getting into the fuel and engine. While water is rarely present in aviation fuel, when it does occur, SAP has been used to prevent it from getting into the aircraft. The aviation industry has committed to phasing out SAP-based water filters used in the refuelling process due to ongoing safety concerns.
If you are concerned about the risks related to refuelling with traditional filter monitors and would like advice from Shell Aviation, please contact us using the contact form. Details of situation and location will dictate the level of support that Shell Aviation may be able to provide. Once your request is received, we will reply as soon as possible. To make it easier for us to assist you, please kindly provide as much information as possible when completing this form.
Click here to view the Questions & Answers from Eliminating the Risk of Refuelling with Traditional Filter Monitors Webinar
Like what you just read? There is more in the Flightpath series, sponsored by Shell.
Please sign up here to receive more Shell Aviation and Flightpath series updates.
Disclaimer
Disclaimer
Cautionary Note
The companies in which Shell plc directly and indirectly owns investments are separate legal entities. In this content “Shell”, “Shell Group” and “Group” are sometimes used for convenience to reference Shell plc and its subsidiaries in general. Likewise, the words “we”, “us” and “our” are also used to refer to Shell plc and its subsidiaries in general or to those who work for them. These terms are also used where no useful purpose is served by identifying the particular entity or entities. ‘‘Subsidiaries’’, “Shell subsidiaries” and “Shell companies” as used in this content refer to entities over which Shell plc either directly or indirectly has control. The terms “joint venture”, “joint operations”, “joint arrangements”, and “associates” may also be used to refer to a commercial arrangement in which Shell has a direct or indirect ownership interest with one or more parties. The term “Shell interest” is used for convenience to indicate the direct and/or indirect ownership interest held by Shell in an entity or unincorporated joint arrangement, after exclusion of all third-party interest.
Forward-Looking statements
This content contains forward-looking statements (within the meaning of the U.S. Private Securities Litigation Reform Act of 1995) concerning the financial condition, results of operations and businesses of Shell. All statements other than statements of historical fact are, or may be deemed to be, forward-looking statements. Forward-looking statements are statements of future expectations that are based on management’s current expectations and assumptions, including (without limitation) those concerning Shell’s strategy and operating plans, macroeconomic conditions, future energy demand, supply and product mix, commodity prices, demand for Shell’s products, production results and reserve estimates, development, execution and management of projects, energy transition and climate change, management of safety and environmental risks, costs, cash capital expenditures, technology advancements, legislative, judicial, fiscal and regulatory developments, regional conflicts and trading conditions, and involve known and unknown risks and uncertainties that could cause actual results, performance or events to differ materially from those expressed or implied in these statements. Forward-looking statements include, among other things, statements concerning the potential exposure of Shell to market risks and statements expressing management’s expectations, beliefs, estimates, forecasts, projections and assumptions. These forward-looking statements are identified by their use of terms and phrases such as “aim”; “ambition”; ‘‘anticipate’’; “aspire”, “aspiration”, ‘‘believe’’; “commit”; “commitment”; ‘‘could’’; “desire”; ‘‘estimate’’; ‘‘expect’’; ‘‘goals’’; ‘‘intend’’; ‘‘may’’; “milestones”; ‘‘objectives’’; ‘‘outlook’’; ‘‘plan’’; ‘‘probably’’; ‘‘project’’; ‘‘risks’’; “schedule”; ‘‘seek’’; ‘‘should’’; ‘‘target’’; “vision”; ‘‘will’’; “would” and similar terms and phrases. There are a number of factors that could affect the future operations of Shell and could cause those results to differ materially from those expressed in the forward-looking statements included in this content, including (without limitation): (a) price fluctuations in crude oil and natural gas; (b) changes in demand for Shell’s products; (c) currency fluctuations; (d) drilling and production results; (e) reserves estimates; (f) loss of market share and industry competition; (g) environmental and physical risks, including climate change; (h) risks associated with the identification of suitable potential acquisition properties and targets, and successful negotiation and completion of such transactions; (i) the risk of doing business in developing countries and countries subject to international sanctions; (j) legislative, judicial, fiscal and regulatory developments including tariffs and regulatory measures addressing climate change; (k) economic and financial market conditions in various countries and regions; (l) political risks, including the risks of expropriation and renegotiation of the terms of contracts with governmental entities, delays or advancements in the approval of projects and delays in the reimbursement for shared costs; (m) risks associated with the impact of pandemics, regional conflicts, such as the Russia-Ukraine war and the conflict in the Middle East, and a significant cyber security, data privacy or IT incident; (n) the pace of the energy transition; and (o) changes in trading conditions. No assurance is provided that future dividend payments will match or exceed previous dividend payments. All forward-looking statements contained in this content are expressly qualified in their entirety by the cautionary statements contained or referred to in this section. Readers should not place undue reliance on forward-looking statements. Additional risk factors that may affect future results are contained in Shell plc’s Form 20-F for the year ended December 31, 2025 (available at www.shell.com/investors/news-and-filings/sec-filings.html and www.sec.gov). These risk factors also expressly qualify all forward-looking statements contained in this content and should be considered by the reader. Each forward-looking statement speaks only as of the date of this content. Neither Shell plc nor any of its subsidiaries undertake any obligation to publicly update or revise any forward-looking statement as a result of new information, future events or other information. In light of these risks, results could differ materially from those stated, implied or inferred from the forward-looking statements contained in this content.
Shell’s net carbon intensity and net-zero emissions target
In this content we may refer to Shell’s “net carbon intensity” (NCI), which includes Shell’s carbon emissions from the production of our energy products, our suppliers’ carbon emissions in supplying energy for that production and our customers’ carbon emissions associated with their use of the energy products we sell. Shell’s NCI also includes the emissions associated with the production and use of energy products produced by others which Shell purchases for resale. Shell only controls its own emissions. The use of the terms Shell’s “net carbon intensity” or NCI is for convenience only and not intended to suggest these emissions are those of Shell plc or its subsidiaries.
Shell’s operating plan and outlook are forecasted for a three-year period and ten-year period, respectively, and are updated every year. They reflect the current economic environment and what we can reasonably expect to see over the next three and ten years. Accordingly, the outlook reflects our combined Scope 1 and 2 target, NCI target and our oil products ambition over the next ten years. However, Shell’s operating plan and outlook cannot reflect our 2050 net-zero emissions target, as this target is outside our planning period. Such future operating plans and outlooks could include changes to our portfolio, efficiency improvements and the use of carbon capture and storage and carbon credits. In the future, as society moves towards net-zero emissions, we expect Shell’s operating plans and outlooks to reflect this movement. However, if society is not net zero in 2050, as of today, there would be significant risk that Shell may not meet this target.
The information provided above regarding Shell’s NCI and net zero emissions target are not intended, nor should they be construed as introducing, suggesting or making any claim, target or representation thereof other than what is included in the content.
Forward-Looking non-GAAP measures
This content may contain certain forward-looking non-GAAP measures such as free cash flow and underlying operating expenses. We are unable to provide a reconciliation of these forward-looking non-GAAP measures to the most comparable GAAP financial measures because certain information needed to reconcile those non-GAAP measures to the most comparable GAAP financial measures is dependent on future events some of which are outside the control of Shell, such as oil and gas prices, interest rates and exchange rates. Moreover, estimating such GAAP measures with the required precision necessary to provide a meaningful reconciliation is extremely difficult and could not be accomplished without unreasonable effort. Non-GAAP measures in respect of future periods which cannot be reconciled to the most comparable GAAP financial measure are calculated in a manner which is consistent with the accounting policies applied in Shell plc’s consolidated financial statements. These forward-looking non-GAAP measures are provided to assist readers in understanding management’s use and expectations of such measures and may not be appropriate for other purposes.
The contents of websites referred to in this content do not form part of this content.
We may have used certain terms, such as resources, in this content that the United States Securities and Exchange Commission (SEC) strictly prohibits us from including in our filings with the SEC. Investors are urged to consider closely the disclosure in our Form 20-F, File No 1-32575, available on the SEC website www.sec.gov.