10th August 2022

Fuel Tables

Initial Report

The company I work for has produced a quarterly fuel & carbon dashboard illustrating Captains’ fuel loading decisions based on a graduated position in relation to peers.  Those to the left of the fleet statistic chart have loaded extra fuel in addition to company SCF (Statistical Contingency Fuel) and those to the right have loaded minimal down to nothing extra on top of SCF.

This rather blunt tool does not reflect a multitude of variables including the assessed airmanship risks of the day that may be deemed to fall outside of the SCF feed data. Much of fuel carriage assessment comes from years of experience, coupled with accurate modern data feeds such as SCF. Fuel carriage decisions include variable/extreme weather, unforeseen level or route deviations that when assessed fall outside of loaded contingency in terms of perceived risk, as well as a comprehensive knowledge of the company fuel policy. This has never been completely black or white and no doubt never will. Indeed, an excellent decision to carry extra fuel based on the crew’s judged risk which subsequently is not used will be shown as discretionary fuel “not required”, perversely moving the Captain to the left of the chart. In reality this is discretionary fuel simply “not used”. Whether it was “required” or not is down to the judgement the Commander utilising knowledge, experience, flight specific data and the full spectrum of the vagaries of the day ahead. The pilot’s arrowed position on the chart simply and crudely represents how much extra fuel was loaded in relation to peer comparison.

Monitoring of SETO (single engine taxi out) & SETI (single engine taxi in) is however a useful area of data supplied, providing it does not encourage “competition”.  Pilots tend to be competitive in nature. Loading sensible fuel loads should be driven primarily on safe practice, followed by commercial awareness and further today, green credentials. Making this decision competitive in this fashion merely interferes with those safe priorities and indeed the focus ought to be equally on those on the right of the scale who think it’s “clever” to blindly rely on SCF data. The unwary will find themselves with low fuel states down a “blind alley”, being driven by an unintelligent and false sense of elitism, to immaturely please their positioning on the chart.

Operating at a zero cost index or selecting speeds close to the best lift/drag ratio speeds to save fuel can place the aircraft in close proximity to VLS (Airbus) causing havoc with ATC & other traffic in close proximity (.72 cruise Mach by example is not practical or ideal). This lack of awareness and due consideration results in other carriers having to alter their trajectories which in turn will damage the collective carbon footprint by increasing collective fuel burn. Further to this if unforeseen turbulence or wake is encountered the safe margins as well as decision options are also compromised.

Enough knowledge exists for all modern commercial pilots to be responsible regarding fuel usage. Intelligent safety orientated and commercial monitoring is no doubt prudent as well as showing responsible carbon footprint awareness. However, to make a competitive incentive to see whom can carry the least fuel can be viewed from a safety perspective as an irresponsible and reckless stance from an airline employer, albeit with good but misplaced motives at heart. Indeed, if a company chooses this behaviour then perhaps a “magnifying glass” ought to be directed at those carrying the least fuel to ensure safe practice.

In summary, the importance of a decision regarding a safe quantity of fuel ought not be influenced by a position on a graph. If it does, then this leads to a question over the quality of Command selection, training and authority regarding safe fuel decisions.

Company Comment

The graph depicts whether Discretionary Fuel was loaded on a flight and whether it had SCF allocated to it or 3%/5% Contingency Fuel. As the reporter correctly explains, the judgement as to whether Discretionary Fuel should be loaded relates to multiple factors but is usually related to destination weather. The benefit of fuel plans which have SCF is that they have some statistical knowledge which can mitigate some of the unknown factors from the fuel decision – for example, a regular early descent, which cannot be flight planned. As for some routes that may well not fit SCF rules, we agree that routes that have insufficient data to provide SCF are more exposed to requiring Discretionary Fuel to be loaded. The benefit in having SCF (95th percentile) is that it provides the crew with a question to ask themselves when deciding on the amount of fuel they are going to load for a flight – “is this the one flight in 20 that requires more fuel than has already been allocated today?” During storm Eunice we added additional fuel to all flights operating during this period and provided Destination Alternates that were not affected by the strong winds and therefore a viable option to use.

The ‘ME’ arrow on the graph shows where the individual is in relation to other Captains on the fleet, and simply shows the application rate of when Discretionary Fuel is loaded (not the amount). For example, a pilot who loads Discretionary Fuel on every flight they operate during the period, would be towards the left-hand side of the graph. This may be due to the fact that the individual was faced with a bad weather forecasts on every flight they operated during the period. The decision to take Discretionary Fuel in such circumstances may be wise considering traffic volumes and/or the destination airport they are operating to. However, it would be unlikely that the same pilot would be faced with bad weather on all of their flights in the next period, so their positioning within the graph is likely to change more to the right because Discretionary Fuel would be less likely to be carried. If the said individual loads Discretionary Fuel for every flight they operate, they would either be extremely unlucky in terms of weather at destination for all the flights they operate, or they lack the confidence in the fuel planning in the flight plan and/or the confidence in understanding fuel policy.

The dashboard is purely for the individual; it allows the individual to see what others are doing on the fleet, without identifying who those individuals are. It allows the individual to assess how effective they are in terms of fuel policy knowledge and fuel saving initiatives compared with other Captains on the fleet. There are no incentives given to pilots who regularly take less fuel than others and, similarly, there are no criticisms given to those who take additional fuel on every flight they operate. With regard to concerns about the influence that chart position has on the decision process and the risks to those carrying inappropriate low levels of fuel, we continue to monitor the amount of low fuel events we have as an airline and these trends have not changed since the dashboards were introduced. We will continue to monitor these events.

With respect to RETO and RETI [aka SETO and SETI in twin-engine aircraft], the use of the dashboard is to show how often a certain initiative is used and is simply there for the individual to see their results alone. They are also able to see what contribution their actions have (be it positive or negative) as to the environmental impact of aviation. Safety is always the primary factor for anything we do at [Airline]. We have every confidence in the quality, standard and training of our pilots, and our fuel policy and company culture ensures that crew always have the authority to make safe decisions, especially in terms of fuel loaded.

CHIRP Comment

We’re grateful for the company’s extensive comments explaining the rationale behind the fuel graphs and their intention to enlighten captains as to fleet norms and encourage them to improve their individual environmental carbon footprint. Notwithstanding, it’s human nature to reflect on one’s own performance in relation to others, and some less experienced captains might conceivably perceive implied pressure or incentives to carry less additional fuel even if they felt they needed it in what was ultimately a safety-critical decision. It’s probably fair to say that some captains may habitually carry too much fuel but, equally, there are probably those who are at the other end of the scale and who habitually accept the bare minimum which could also be a cause for concern. Ultimately, the decision on fuel loads is dependent on many factors that are route and weather dependent and, if used in the intended manner, at least the company’s charts and fuel calculations offer a basis for decision-making on the day given that they take route factors into account by using a statistical norm for what additional fuel was required from the last 100 flights.

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