Israel’s F-35I fighter jets to get external fuel tanks

Israel’s Ministry of Defense has signed a contract worth over $34 million with Elbit Systems subsidiary Cyclone to develop external fuel tanks for the F-35I Adir fighter jet, extending the stealth aircraft’s range and reducing its dependence on aerial refueling for long-range missions across the Middle East.

The Defense Procurement Directorate of the Israel Ministry of Defense announced the contract, which covers the development and integration of external conformal or drop tanks based on an existing Cyclone design originally developed for the F-16.

Cyclone, a wholly owned subsidiary of Elbit Systems specializing in airborne systems and structural components, brings an established fuel tank engineering pedigree to the F-35 application, drawing on its F-16 work to adapt a proven design philosophy to a fundamentally different airframe. The deal is valued at over NIS 100 million, equivalent to over $34 million at current exchange rates.

The F-35I Adir, the Israeli variant of Lockheed Martin’s F-35A, entered Israeli Air Force service in 2017 and has since become a central element of Israel’s strategic strike capability. Israel has used the Adir in combat operations, including strikes against targets in Syria and Iran, making it one of the few air forces to have employed the F-35 in actual combat. The aircraft’s stealth characteristics, sensor fusion, and electronic warfare suite give it capabilities that no other aircraft in Israel’s inventory can replicate, but those advantages come with a range limitation that has strategic implications for a country whose most pressing potential targets lie at the outer edges of the aircraft’s unrefueled combat radius.

The F-35A in its standard internal fuel configuration carries approximately 18,000 pounds of fuel and has an unrefueled combat radius of roughly 700 miles on a typical strike profile. For the Israeli Air Force, which has consistently identified Iran’s nuclear program as its most critical long-range strike challenge, that range requires careful mission planning, aerial refueling support, or potentially routing through third-country airspace to reach targets in the Iranian interior. External fuel tanks address the range constraint directly, at the cost of increased radar cross-section — a meaningful trade-off for an aircraft whose value is partially predicated on its low observability.

The aircraft was designed for internal weapons and fuel carriage precisely to maintain the low-observable airframe geometry that makes it survivable in contested airspace. External tanks, which disrupt that geometry by adding protrusions and surface area that reflect radar waves, represent a departure from the stealth-optimized baseline configuration. That trade-off is operationally acceptable in many scenarios, particularly if the external tanks are jettisoned before entering the highest-threat portions of a mission’s route, but it is a genuine capability consideration that distinguishes an F-35 carrying external tanks from one flying internally clean. The extent to which Cyclone’s design mitigates this penalty through conformal shaping or other low-observable features is not specified in the available source material.

Cyclone’s foundation in F-16 external fuel tank development gives the project a starting point that is engineering-validated rather than notional. The F-16 has operated with various external tank configurations throughout its service history, including 370-gallon and 600-gallon centerline and wing tanks that have been integrated on Israeli F-16s specifically. Adapting that institutional knowledge to the F-35’s different aerodynamic and structural envelope is a technical challenge, but it is one that benefits from Cyclone’s existing familiarity with how conformal and external tank systems interact with fighter airframe loads, fuel transfer systems, and weapons station interfaces.

Israel’s Defense Minister Israel Katz and Director General Major General (Ret.) Amir Baram have framed the contract within the IMOD’s broader force buildup strategy for what they describe as an intense security decade ahead. That framing reflects the Israeli government’s assessment that the threat environment it faces — particularly from Iran’s nuclear and missile programs and from the network of Iranian-backed regional proxies – will intensify rather than stabilize over the coming years, requiring sustained investment in long-range strike capability and strategic depth. Extending the Adir’s operational range reduces dependence on aerial refueling aircraft, which are themselves high-value, limited-inventory assets that must be positioned and protected during long-range missions, and enhances the operational flexibility that mission planners need when designing strike packages against hardened, distant targets.

The Israeli Air Force’s combat employment of the F-35 against targets in Syria and, more recently, Iran, has provided real-world operational data on the aircraft’s performance in the most demanding air defense environments outside of a peer-versus-peer conflict. That operational experience has presumably informed Israeli Air Force requirements for the extended-range capability, giving the Cyclone development contract a specificity of operational purpose that theoretical range extension programs often lack. What the Israeli Air Force knows from experience about what range it needs, what threat environments it must penetrate, and what the trade-offs between stealth and range mean in practice is the operational foundation on which this $34 million contract rests.