Five noteworthy aviation sustainability developments in the past seven days curated by the Ishka Airfinance SAVi team.
Here are the new developments to keep in mind:
1. Arcadia secures 40,000t/year Uniper e-SAF offtake
e-SAF: German state-owned utility company Uniper on 23rd September signed a legally binding long-term offtake agreement with Arcadia eFuels for 40,000 tonnes of e-SAF per year for more than ten years from Arcadia’s Project Endor in Vordingborg, Denmark. Deliveries are currently expected to begin in the early 2030s, subject to agreed conditions and the plant entering commercial operation. The plant is planned to produce 80,000 tonnes of e-Fuels annually, with e-SAF as its primary product, meaning the Uniper agreement would account for a substantial share of planned output.
The deal, representing more than 400,000 tonnes of contracted eSAF, is one of Europe’s largest announced e-SAF offtakes to date, second only to IAG and Twelve’s 2024 agreement for 785,000 tonnes of e-SAF over 14 years, equivalent to around 56,000 tonnes per year.
When Ishka Airfinance spoke with Arcadia CEO Amy Hebert in August 2025, the developer highlighted long-term offtake certainty as a key requirement for advancing e-SAF projects. Project Endor since secured an EU Innovation Fund grant agreement in March 2026 and Arcadia said in March that it was continuing to advance the project towards FID. German fund manager KGAL, active in aircraft investment notably through its in-house lessor GOAL, also invested in the Vordingborg project in 2023 via its energy-transition fund KGAL ESPF 6.
The deal was announced two days after Germany, Austria and Luxembourg launched a joint e-SAF funding scheme worth up to €2.12 billion ($2.4 billion). The three countries plan to set up a double-sided auction. The scheme remains subject to European Commission state-aid approval.
2. Over half of airline CapEx classified as EU Taxonomy-aligned
EU Taxonomy: New research from CE Delft, commissioned by NGOs Opportunity Green and Fossielvrij NL, published on 23rd September, argues that the EU Taxonomy’s aviation criteria are allowing large amounts of conventional aircraft spending to be classified as sustainable investment. The analysis found that 52.8% of reported airline CapEx in 2025 was Taxonomy-aligned, equivalent to €9.57 billion ($10.9 billion). Almost all of this – €9.5 billion ($10.8 billion), or 52.67% of total CapEx – was classified as “transitional” expenditure, predominantly covering new conventional-powered aircraft (referred in the report as "fossil-fuel-powered") and aircraft maintenance. Just €24 million ($27 million), or 0.13%, related to activities the report categorises as sustainable, principally electric ground-handling equipment.
The report further argues that aviation is unusually generously treated compared with other sectors, as it was the only one of 115 sectors examined where more than half of total CapEx was classified as aligned transitional expenditure. It therefore contends the criteria are capturing routine fleet renewal that would have taken place regardless of the Taxonomy, and does not require a significant shift in investment towards lower-carbon technologies.
The report also criticises the Commission’s 2026 proposed revisions to the aviation criteria, which would extend the period during which qualifying aircraft can be Taxonomy-aligned from 2027 to the end of 2029, while delaying the point at which aircraft certified for 100% SAF operation become eligible under another criterion from 2028 to 2030.
The report comes days before the EU General Court is scheduled to deliver its judgment on a 2024 legal challenge brought by environmental NGOs against the Commission’s refusal to reconsider the aviation Taxonomy criteria (see more details on the challenge here).
3. A4E urges Parliament to convert aviation's full ETS payments into SAF allowances
EU ETS: Airlines for Europe (A4E) on 21st September renewed calls for a greater share of aviation revenues under the EU ETS to be reinvested in sector decarbonisation, responding to a new European Parliament draft report on the Commission’s 2026 ETS revision. The draft report from ENVI rapporteur Peter Liese proposes requiring Member States to reinvest 75% of ETS auction revenues in ETS-covered sectors, compared with 50% under the European Commission’s July proposal. The legislative file is awaiting a committee decision, with a first-reading plenary vote currently indicated for December.
A4E welcomed the greater focus on using ETS revenues for decarbonisation but argued that the approach does not go far enough for aviation, estimating that, under the proposed revision, only 13% of aviation ETS payments would be converted into allowances supporting SAF uptake. The airline association is calling for airlines to be able to convert their full ETS payments into SAF allowances, which it says would help bridge a “four- to ten-fold cost gap” between SAF and conventional jet fuel and support additional SAF offtakes and production. A4E also wants the mechanism to remain technology-neutral, arguing that removing support for HEFA SAF in 2029 would be “premature”.
Separately, the association continues to oppose extending the geographical scope of the EU ETS beyond the EEA, arguing this would undermine CORSIA, and says ETS funding should not be used for contrail avoidance, which it views primarily as an airspace and air-traffic-management issue.
4. Heart Aerospace redesigns aircraft with two motors, firms JSX order
New propulsion: Heart Aerospace on 23rd September unveiled an updated design for its production hybrid-electric regional aircraft, now called the ES-36 and featuring two (instead of four) motors and six additional seats over the preceding ES-30. Alongside the unveiling, US carrier JSX announced a “deposit-backed purchase agreement” (firming a previous letter of intent) for 50 ES-36 aircraft, with purchase rights for 50 more. The ES-36 also adds 1,415 pounds (642 kg) of payload capacity, while retaining the same maximum take-off weight and battery capacity as the prior design. The ES-36 adopts twin series-hybrid powertrains, with each utilizing a 1.65 MW electric motor to drive a propeller. The aircraft has an all-electric range of 125 miles (200 km), plus reserves, and a hybrid range of 745 miles (1,200 km), plus reserves. It is 11 feet (3.35m) shorter than the ES-30. The unveiling of the ES-36 follows the mid-August first flight of the company’s X1 demonstrator.
5. Bye Aerospace eFlyer 2 electric trainer aircraft completes first flight
New propulsion: Bye Aerospace announced on 24th September the successful first flight of the eFlyer 2 production prototype, an electric trainer aircraft. The flight marks a major milestone for the Colorado-based company, which is targeting the flight training market before moving to larger aircraft (see this IA SAVi interview with CEO Rod Zastrow). The eFlyer 2 combines an advanced electric propulsion system with a lightweight composite airframe and safety-focused design to reduce operating costs by up to 80% while eliminating in-flight emissions. The eFlyer 2 completed its planned flight test profile from Centennial Airport near Denver, Colorado. The aircraft integrates technologies from, among others, Safran Electrical and Power, magniX, Siemens, Toray, Composite Approach, Garmin, Sensenich Propeller, Electro.Aero, Flying S, M4 Engineering, ACME Aero, and Risse Racing. The firm is also developing a stretched four-seater eFlyer 4 and, as of 2021, had plans for a larger eight-seater eFlyer 800.
Also this week: Ishka Airfinance partner PACE, Fexco’s sustainability data and analytics division, announced a strategic combination with RDC Aviation, a leading global provider of aviation data and market intelligence. The combination brings together commercial aviation intelligence, carbon analytics and complementary global customer networks. To learn more, see this week’s announcement.
