What we observed

This signal states that aviation operators continue to rely on conventional jet fuel as their primary energy source.

These are about the broader oil-dependence of the chemical industry, not aviation fuel specifically, and should be treated as adjacent context rather than direct evidence for this signal.

A second, more directly relevant cluster does exist: IATA's Sustainable Aviation Fuel fact sheet and SAF overview page, the European Alternative Fuels Observatory's page on alternative fuels used in aviation, a KPMG piece on the development of alternative aviation fuels, and academic/industry reviews (ScienceDirect on alternative sustainable aviation fuel and energy, Springer on the research status of aviation alternative fuels). These items are genuinely on-topic for the aviation fuel question, though notably, each of them is framed around the *search for* and *development of* alternatives — which is consistent with, rather than a direct confirmation of, the claim that conventional jet fuel remains the dominant fuel in actual operational use.

What is changing

Historically, commercial and cargo aviation has run almost entirely on petroleum-derived jet fuel (Jet A and Jet A-1), with global refueling infrastructure, aircraft engine certification standards, and fuel procurement contracts built around this single, standardized fossil energy source for the better part of a century. This is the previous behaviour baseline against which this signal should be read.

What is emerging, based on the surrounding evidence pool, is not a change in that baseline but a parallel, growing body of activity around alternatives: SAF fact sheets from industry bodies like IATA, government-adjacent observatories tracking alternative aviation fuels in the EU, consulting-firm analysis of alternative fuel development, and a steady stream of peer-reviewed research into aviation alternative fuels and energy systems. The signal's own claim is that despite this visible activity, the underlying operational behaviour — which fuel actually powers the majority of flights — has not shifted. In other words, the change observed here is in the volume and visibility of alternative-fuel discourse and pilot activity, not in the fuel mix itself.

This is an important distinction for how the signal should be interpreted: it is tracking the persistence of a status quo in the face of rising counter-pressure, rather than tracking an active behavioural pivot by operators.

Why this matters

If accurate, this pattern of continuity matters because aviation is widely regarded as one of the most difficult sectors to decarbonize, given the energy density requirements of jet propulsion and the long asset lifecycles of aircraft and fueling infrastructure. A persistent gap between stated industry ambition around SAF (visible in the IATA and EU observatory materials) and actual fuel substitution has direct consequences: it affects the credibility of airline net-zero pledges, the pace at which regulatory blending mandates can realistically be enforced, and the risk profile for capital being deployed into SAF production, alternative feedstock supply chains, and next-generation propulsion technologies.

For adjacent industries — corporate travel buyers under emissions disclosure pressure, freight and logistics firms with scope 3 exposure to air cargo, and financial institutions financing aviation assets — the practical fuel mix, not the stated ambition, is what ultimately determines emissions outcomes. A signal indicating continued reliance on conventional fuel, even at low confidence, is a useful counterweight to more optimistic narratives built primarily on announcements, pilot programmes, and blending targets rather than realized fuel volumes.

The broader petrochemical-feedstock evidence in the linked pool, while not specific to aviation, reinforces a plausible structural driver: oil-derived inputs remain deeply embedded across multiple industrial systems, and aviation fuel substitution is one instance of a wider, slower-moving transition away from petroleum feedstocks generally.

How strong is the evidence

Within that pool, source diversity is reasonable in principle — items originate from industry bodies (IATA, KPMG), an EU government-linked observatory, academic publishers (ScienceDirect, Springer), an EU research portal (CORDIS), and general web sources — but roughly half of these sources are addressing petrochemical feedstocks in general rather than aviation fuel specifically, which dilutes how much of this pool can honestly be called on-topic. None of the linked items contains a direct, quantified statement of current SAF blend share or conventional-fuel dependency percentage that would directly substantiate the claim; the on-topic items are more about the existence and development of alternatives than about the current scale of operator reliance on conventional fuel.

Taken together, this signal should be read as directionally plausible and consistent with general industry knowledge about aviation's fuel dependency, but formally under-evidenced and not yet independently corroborated.

What we're watching next

Quettor will be watching for evidence that either strengthens or weakens this reading. Strengthening evidence would include quantified SAF blend-rate data from airlines or regulators showing what share of total aviation fuel volume is currently non-conventional, repeated observation of this signal across multiple collection dates (establishing time consistency), and corroboration from additional independent signals that could elevate this into a validated pattern. Weakening or complicating evidence would include data showing a faster-than-expected rise in SAF blending mandates being met, announcements of significant SAF production capacity coming online, or airline-reported fuel procurement figures showing a meaningful non-conventional share. It will also be important to track whether future evidence collection produces items specifically about aviation fuel consumption shares, rather than the current mix, which leans toward alternative-fuel development activity and adjacent petrochemical-feedstock discussion rather than direct operational fuel-use data.