Optimizing fuel efficiency in today’s aviation landscape is crucial for cost savings and sustainability. In this interview, Viva Aerobus' Head of Fuel Efficiency, Nancy Madrigal, explores how the airline leveraged advanced analytics to reduce Zero Fuel Weight discrepancies and improve its fuel efficiency.
What is Zero Fuel Weight and how it can impact aircraft fuel efficiency
Fuel efficiency is influenced by aircraft performance during flights and the accuracy of pre-flight data, such as Zero Fuel Weight (ZFW). This is a critical input in flight planning, and any discrepancy between the planned and actual ZFW—known as ZFW error—can significantly impact fuel consumption, flight safety, and even operational costs.- An overestimated ZFW leads to excess fuel being loaded, increasing aircraft weight and, thus, fuel burn.
- The other way around, an underestimated ZFW risks inadequate fuel loading, forcing pilots to compensate with additional fuel, which also harms efficiency.
Related Content >>> All you need to know about Zero Fuel Weight Error and how to reduce it
Airline Case Study: Reducing a 2.1 tons error in Zero Fuel Weight
How VivaAerobus' team improved ZFW - explained
One of the first queries Viva Aerobus’ team created using SkyBreathe® Analytics Query Editor was designed to compare the planned and the actual Zero Fuel Weight across their operations.
Upon analyzing the detailed data generated by this query, the airline uncovered a significant delta of approximately 2,100 kg (2.1 tons) between the planned and actual ZFW on their flights. This large difference had been driving inefficiencies, increasing fuel consumption, and inflating operational costs for the airline, so it had to be corrected.
The first step in solving this issue was to identify the root causes of the ZFW discrepancy and implement targeted strategies to reduce the delta.
Step 1: Customizing passenger weight by route
One of the primary contributors to the ZFW error was an overestimation of passenger weight. Viva Aerobus analyzed historical data from checked baggage and implemented a new process where specific passenger weights were assigned based on the route taken.
"We began to implement different strategies to try to reduce this delta. We started by having a specific passenger weight per route, based on the data we had about checked baggage's weight. We inserted that in our flight planning system as a first step." Nancy Madrigal explained.
Step 2: Refining weight segmentation between adults & children
In their assessment, Viva Aerobus realized that their flight planning system did not differentiate weight between adults and children when calculating total passenger weight. This oversight was causing further discrepancies in Zero Fuel Weight calculations. By introducing a segmentation system that assigned separate weights to adults and children, Viva Aerobus hoped to further reduce the ZFW delta.
However, after analyzing the updated data, they found that this helpful segmentation was not enough to eliminate the error.
"After this implementation we analyzed the numbers in the query but we didn’t see a very high improvement in the numbers. This helped us to detect that something else was wrong with our segmentation in the flight planning system." shared Nancy Madrigal
Step 3: Implementing a no-show factor
Recognizing that no-show passengers could also contribute to ZFW errors, the airline introduced a no-show factor into its flight planning system.
This adjustment helped correct passengers who failed to board, ensuring that fuel was not being loaded unnecessarily for absent passengers.
"After fixing the segmentation between adults and children and the implementation of the no-show factor, we started seeing real improvement in the delta of Zero Fuel Weight, reaching up to 500 kg, 550 kg of delta as average in the last month," detailed Viva Aerobus' Head of Fuel Efficiency.
The results
Using advanced data analysis insights and swift implementation of corrective measures, Viva Aerobus successfully reduced around 74% of their ZFW delta from over 2,100 kg to an average of 500-550 kg (0.5 tons) per flight.
"Without our SkyBreathe® Query Editor, we wouldn’t have been able to monitor if the actions we were implementing were correct and actually working," emphasized the representative from Viva Aerobus.
This improvement directly impacted the airline’s fuel consumption, reducing unnecessary fuel burn and delivering substantial cost savings.
Regarding fuel savings, not carrying those extra 1500kg represents around 1.8kg of fuel saved per flight for the airline. Considering the whole fleet and network at VIVA, the estimated fuel savings are around 125 tons per year or around 400 tons of C02.
Check out Nancy Madrigal's full interview!
LEARN MORE
[CASE STUDY] Discover VivaAerobus' impressive path to mastering fuel efficiency.
Read the full interview:
What are the main advantages/benefits of SkyBreathe® Analytics?
The biggest advantage of SkyBreathe® is that you can actually measure fuel efficiency in a precise way.
You can create a detailed picture to see how your company is performing with various fuel conservation projects.
Having this complete picture makes it easier to identify areas of opportunity, start improving, and think about how to be more efficient and greener.
Can you share a concrete use case where SkyBreathe® Analytics helped you achieve your goals?
The first example that comes to my mind is the improvement we made with the Delta Zero Fuel Weight. This was one of the first queries we created as a company with SkyBreathe®.
The team built a query that compares the planned Zero Fuel Weight and the actual Zero Fuel Weight. When we ran the query, we saw a large delta: about 2100 kg, which was a big difference.
We got to work! We implemented several strategies to reduce this delta.
First we assigned a specific passenger weight per route based on the data we had about checked baggage, which we then added to our flight planning system.
Then, we performed a weight segmentation between adults and children. Our flight planning system didn’t automatically separate these groups, so children were assigned an adult weight, which wasn’t accurate.
After implementing these changes, we reviewed the numbers again, but we didn’t see a significant improvement. This helped us identify that there was still something wrong with our segmentation in the flight planning system.
We made the necessary corrections, and in parallel, we added a no-show factor to our flights in the flight planning system.
Once we fixed the segmentation and implemented the no-show factor, we started seeing a real improvement in the Delta Zero Fuel Weight, reducing the delta to around 500–550 kg on average over the last month.
But without our SkyBreathe® query, we wouldn’t have been able to monitor whether the actions we were implementing were correct and whether the implementations were actually working.
As a SkyBreathe® Advisor beta tester, can you describe your overall experience with these new features? What are the main benefits?
I think Advisor is easy to use and has a lot of potential.
At Viva, we don’t currently have the Continuous Descent Approach (CDA) best practice available in SkyBreathe® MyFuelCoach for pilots. Some pilots say it’s not possible or really difficult to perform because of CDA constraints.
However, the insights we've gained from SkyBreathe® Advisor have shown us that we can still implement this practice, as some pilots are already doing it. This is something we can start monitoring and encourage more pilots to adopt.
What does the SkyBreathe® Community mean to you?
I really love being part of this community. Through OpenAirlines I have been able to connect with colleagues from all around the world. It’s a great way to exchange experiences, not just about fuel efficiency, but also about life in general and aviation, which we are all passionate about.
I’m really happy to be a part of this community, and I’m really thankful to the OpenAirlines team for always being open to feedback and making us feel heard. This is really valuable to both me and my company.
What aspect of the OpenDay conference do you find the most valuable?
OpenDay is about the community and about to know people from different airlines with different fleet, different objectives, different sizes. But I think everybody in the community is sharing one common objective: to have a better and greener future in aviation.
What has been the most enjoyable or memorable part of the conference for you so far?
I was really excited when you presented the new version of SkyBreathe® MyFuelCoach. It’s a fresh version of the app, and I’m sure my pilots will be thrilled with it. I can’t wait to show them the new features through videos, meetings, and a tour around our base.
I think that is going to be really great for us.
Also, I really enjoyed the boat trip along the river here in Toulouse. Watching the sunset while connecting with people was a special moment. It was a nice break and a memorable experience.
