Israel’s F-35I “Adir” features unique modifications no other operator is permitted to make—including the United States itself
When countries purchase the F-35 Lightning II from Lockheed Martin, they receive a sophisticated stealth fighter with one major caveat: strict rules prohibit any modifications whatsoever. Unauthorized tinkering is forbidden, and only U.S.-run facilities can service the aircraft. These non-negotiable rules protect sensitive technology and maintain the aircraft’s deeply integrated systems.
Unless you’re Israel.
The Only Exception
Israel is the only country the United States has approved to modify its F-35s, creating a unique variant called the F-35I “Adir” (Hebrew for “Mighty One”). Through contractual agreements with Lockheed Martin, Israel secured rights that make their F-35I variants optimized for Middle East conflicts—and potentially the most capable F-35 variant in the world.
Israeli-Specific Technology
The modifications go far beyond cosmetic changes. Israeli F-35Is feature indigenous electronic warfare systems optimized for regional threats like advanced Russian air defenses operated by Iran and Syria. The aircraft includes a “plug-and-play” main computer architecture that allows integration of Israeli weapons systems without compromising the base platform.
Perhaps most significantly, Israeli engineers developed an overriding Israeli-built command and control program that runs on top of Lockheed’s operating system. This ensures compatibility with datalinks used by Israeli air and ground forces—critical for tracking hostile surface-to-surface rocket launchers and surface-to-air missile systems across the region.
Israel even manufactures unique wings domestically, making the F-35I structurally distinct from any other variant.
Extended Range for Iranian Targets
Israel’s modifications prioritize one critical capability: striking distant targets without aerial refueling. The Israeli Air Force has developed extended-range modifications including external fuel tanks that enable direct strikes against Iranian nuclear facilities and air defense systems without requiring tanker support.
This capability proved crucial during recent operations against Iran, fueling speculation about just how far Israel has pushed the F-35’s range envelope beyond standard specifications.
Domestic Maintenance Freedom
Unlike every other F-35 operator, Israel maintains its fleet domestically. Israel’s Nevatim Air Base hosts dedicated F-35 maintenance facilities, giving Israeli engineers unrestricted access to the aircraft for upgrades and modifications. Other operators must send their aircraft to specialized Lockheed facilities for any work beyond routine maintenance.
Israel also received the only F-35 testbed aircraft ever delivered to an air force outside the United States, enabling continued domestic development and testing.
Combat-Proven Advantage
On May 22, 2018, Israeli Air Force commander Major General Amikam Norkin announced that Israel had become the first country in the world to use the F-35 in combat. Since then, Israeli F-35Is have accumulated over 15,000 operational flight hours across multiple combat theaters.
The aircraft’s capabilities were demonstrated during strikes against heavily defended Iranian targets, where Israeli modifications to electronic warfare systems and extended range proved decisive in penetrating sophisticated air defenses.
The Strategic Calculation
The United States granted Israel these unprecedented privileges for strategic reasons. Israel faces immediate, advanced threats from state actors equipped with Russian air defense systems—threats most other F-35 operators don’t regularly confront. Israeli combat experience and technological feedback benefit the broader F-35 program, even if American pilots never fly the specific Israeli variant.
As of 2025, Israel operates 46 F-35I aircraft across three squadrons. The modifications ensure that Israel’s F-35s aren’t just equivalent to the American version—in certain critical respects, they’re ahead.
