Everything airlines need to know about Statistical Taxi Fuel

In the world of commercial aviation, fuel management is a critical component of flight planning. Airline dispatchers prepare flight plans, ensuring that the aircraft carries the optimal amount of fuel for its journey. Several variables go into determining the necessary fuel load, and among these considerations is a small but vital component: taxi fuel.

🔎 Did you know that for a 10 hours flight in a A350, adding 10kg (22 lbs) of taxi fuel will emit about 11kg (24 lbs) of CO2 on the whole flight ? 

Let’s dive into how taxi fuel can help your airline optimize fuel efficiency.

What is the taxi fuel?

Taxi fuel refers to the fuel needed to move an aircraft from its parking position to the runway before takeoff and from the runway to its gate after landing.

As mentioned earlier, dispatchers create the flight plan detailing the minimum fuel required for the journey between airports. They determine the fuel needs for a flight by considering aircraft performance, any Minimum Equipment List (MEL) or Configuration Deviation List (CDL) items, the intended route, weather conditions, and all legally required reserves for contingencies, holding, alternate airports, and more.

Dispatchers are used to determine the exact amount of fuel needed based on these factors. However, for taxi fuel, most airlines still use a flat rate regardless of the departure airport—typically 200 kg (441 lbs) for a B737 or an A320.

Related content >>> How to reduce dispatcher extra fuel without compromising safety

Planning the right amount of taxi fuel before the flight is challenging. Although taxiing may seem like a minor part of the flight, failing to calculate this fuel accurately can have significant consequences.

On the one hand, insufficient taxi fuel can compromise safety. On the other hand, too much taxi fuel incurs substantial additional costs, not just financially but also by increasing fuel burn and CO2 emissions. Thus, it is important to find the right balance.

Take the example of Greater Bay Airlines: by defining a new policy for the planned taxi fuel the airline now saves more than 300kg (661 lbs) of fuel per day, representing an offset of 1 ton of CO2 per day.

This new policy, named  Dynamic Taxi Fuel at GBA, consists in adjusting more precisely the planned taxi fuel at each airport with the support of SkyBreathe® Analytics' data. 

Related content >>> Why optimized taxi fuel should matter to you?

Statistical Taxi Fuel Policy definition:

The efficiency of a taxi fuel policy can be measured using three key criteria:

1. Actual fuel consumption: by comparing actual fuel consumption to the planned amount, you can determine whether the policy is too aggressive. Ideally, actual consumption should match the planned fuel amount.

2. Pilot confidence: to gauge this, compare the amount of extra fuel requested by pilots before and after implementing the policy. If extra fuel requests increase, it indicates pilots don't trust the planned fuel quantities, which can be counterproductive.

💡 Building pilot trust is essential, and clear communication, either through discussions or pilot debriefing tools like SkyBreathe® MyFuelCoach, can help. 

SkyBreathe® MyFuelCoach pilot app

3. Reserve fuel usage: compare the use of reserve fuel before and after the policy change. For example, what percentage of flights have had to use their reserves? Understanding the cause of these anomalies allows for case-by-case adjustments.

Now that we have a better understanding of this practice, let's examine the key criteria your airline must consider when implementing it.

Tips to implement a Statistical Taxi Fuel approach in your airline ops

Which criteria do you have to take into account?

In order to apply the adapted policy to your airline, you need to consider different elements. The most important thing is to know how you define planned taxi fuel. To do so, you have to keep in mind several questions:

• Do your flights apply single-engine taxi (EOTO) in this airport?
• Do your pilots use APU during taxi out?

If yes, you need to know if you consider these particular operations in your flight plan. Moreover, you can even decide to consider the fuel burnt during the whole ground static phase.

Thus, your statistical approach will consider these parameters, and the results will be relevant and adapted to your operations.

When should you update and optimize the policy?

The closer your planned taxi fuel is to the actual taxi fuel, the more savings you make. In an ideal world, the policy should be changed for each flight, considering each parameter (weather, traffic, passenger weight, etc). But today, changing the taxi fuel policy for each flight is unrealistic.

Depending on the seasonality of your operations, we recommend changing your policy at least once or twice per year.

💡 For example, suppose your operations indicate that aircraft consume more fuel during a certain period of the year. In that case, you'll recommend a "higher" fuel policy for that season, which will be more reliable for safety reasons. However, during the other seasons, you will have a "lower" recommendation that will better suit your operations and allow you to achieve more significant savings.

To sum up 

This data-driven method allows you to fine-tune your fuel estimates, avoiding the risks associated with underfueling while eliminating the waste of excess fuel. Ultimately, optimizing taxi fuel not only enhances safety and operational efficiency but also contributes to significant fuel savings and CO2 emissions reduction. By embracing these fuel efficiency best practices, you can balance economic performance and environmental responsibility.

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[CASE STUDY]  Discover how Azul Linhas Aéreas streamlined fuel efficiency by transitioning from an in-house system to a cloud-based solution, integrating advanced data analytics and a dedicated pilot app.

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