The Israeli military continues to engineer new external fuel tanks for its specially configured “Adir” variant of the F-35 stealth fighter jet. The Adir, or F-35I, is an aircraft tailored by Israel for unique mission sets particular to address the kinds of enemy threats Israeli forces are likely to encounter. Simply put, extra fuel tanks can massively extend strike range and multiply combat options for Israel, should it be confronted with an operational need to attack enemies at greater distances than an F-35 fighter could normally reach.
According to an Israeli news site called Walla, the Israeli Air Force Flight Testing Center (FTC) at Tel-Nof Air Force Base is “developing the external drop tanks that will help the Adir to complete long-range missions over “third circle” targets, such a hypothetical strike against Iranian objectives.”
The first studies for new fuel tanks started at least during the system design and development phase (SDD) of the fifth-generation aircraft several years ago, Walla report, but nothing new appears to have surfaced in the last few years.
While the concept of external fuel tanks may upon initial examination seem to greatly reduce the stealth properties of an F-35 jet, the fifth-generation aircraft may indeed be able to preserve its low radar signature with extra tanks. How? Well, the Israeli report did not show any images or renderings of what an extra additional fuel tank may look like on the jet, yet previous instances of external fuel tanks such as the “conformal tanks” built onto the Navy F/A-18 fighter jets indicate that it is possible to align the configuration of the extra tanks along the body of the fuselage in a way that preserves blended wing-body stealth shapes, edges and contours.
Regardless, the addition of any degree of extra “metal” flying through the air, no matter how stealthily it is engineered, may increase the detectability of the jet, however perhaps not to a degree sufficient to render it vulnerable to Iranian S-400 air defenses. Also, the added range capacity afforded by the extra tanks increases strike reach and, of equal or greater significance, substantially enhances mission “dwell time” over target enabling F-35I jets to hunt for and strike targets on a single mission. This kind of added time on missions during strikes could prove to be of particular relevance in the case of Iran, because Israeli F-35 fighters would not only have to cross the Persian Gulf but also likely face off against a large number of Iranian targets. There may be mobile enemy missile launchers which require the F-35I’s drone-like surveillance to locate. Or there could be sensitive and somewhat obscured high-value targets such as nuclear facilities not easily attacked during short-duration missions. The longer a single F-35I fighter can operate over a particular area of operations, the less there may be a need for additional aircraft. This is important because fewer warplanes would make any air attack less detectable to Iranian radar.
The extra tanks for the Adir jet may prove particularly crucial given that Israel may not have an aerial refueler sufficiently stealthy or well positioned to add fuel to F-35 fighters during attack operations. Unlike the U.S. Navy which operates the carrier-launched MQ-25 Stingray refueler drone to extend maritime power projection, the Israeli military may not have a comparable ability to add fuel to the fifth-generation aircraft while in flight. Certainly, the existence of something like the Stingray drone can, in the case of the U.S. Navy, almost double the strike range and dwell time of carrier-launched F-35C stealth fighter jets.
Kris Osborn is the defense editor for the National Interest. Osborn previously served at the Pentagon as a Highly Qualified Expert with the Office of the Assistant Secretary of the Army—Acquisition, Logistics & Technology. Osborn has also worked as an anchor and on-air military specialist at national TV networks. He has appeared as a guest military expert on Fox News, MSNBC, The Military Channel, and The History Channel. He also has a Masters Degree in Comparative Literature from Columbia University.