Der F-16 Fighting Falcon first flew in 1974. More than fifty years later, eight countries have collectively put around a billion dollars into making sure it can still survive a modern air defence network — and almost none of that money has gone into the airframe.

It has gone into a box. On 3 September 2026 L3Harris announced it had finished building the first 35 Viper Shield electronic warfare systems and was ramping towards full-rate production of the 233 on order.

Which is a quiet way of saying that the most important upgrade on a modern fighter is usually invisible.

What an electronic warfare suite actually does

Strip away the marketing and a fighter’s EW suite performs two jobs. First it listens, constantly, across a very wide slice of the radio spectrum, and works out what is illuminating the aircraft: a search radar, a fire-control radar, a missile seeker, and which specific type of each.

Then it lies. Having identified the threat, it transmits a signal engineered to make the enemy radar believe something untrue — that the aircraft is somewhere it is not, that there are several of them, or that there is nothing there at all.

Trade reporting describes Viper Shield as pairing a digital radar warning receiver with jamming based on digital radio frequency memory. DRFM is the technique that makes modern deception work: the system captures the incoming radar pulse, stores it digitally, alters it precisely, and sends it back. Because the returned signal is a modified copy of the radar’s own transmission, it looks exactly like a legitimate echo.

How radar jamming works, from early noise techniques to modern digital deception.

Why the F-16 needed it

The F-16 was designed as a small, cheap, agile day fighter. Survivability came from being hard to see and hard to hit. That logic has not aged well against modern integrated air defences with long-range radars, networked sensors and missiles that no amount of agility will out-turn.

The Block 70/72 answer has been to rebuild the aircraft’s senses: the APG-83 active electronically scanned array radar, new avionics, and now a new electronic warfare suite designed alongside them rather than bolted on afterwards. That integration matters, because a radar and a jammer that do not know what each other are doing will happily interfere with one another.

Eight countries paying for one American system

The financing is the genuinely unusual part, and L3Harris has been unusually direct about it. Development, laboratory work, flight testing and current production have been funded largely by foreign customers, not by the U.S. Air Force.

That is a sales pitch aimed squarely at Washington, and it inverts the usual pattern. Normally the U.S. services fund a system and allies buy it afterwards. Here the allies have paid to build it, and the company is inviting the U.S. Air Force to buy in at the back end and skip the development bill.

The advantage for later customers is the same in reverse. Peru, which selected Viper Shield in August 2026, joins a programme with an open production line and a supply chain already running.

The pod is the interesting bit

Alongside the first 35 systems, L3Harris assembled its first external pod built from production hardware. That single sentence widens the market enormously.

Integrating an EW suite inside an airframe is invasive and expensive; it means wiring, antennas, cooling and recertification. A pod hangs on an existing station. For the very large number of older F-16s flying worldwide that will never be rebuilt to Block 70 standard, a pod is the difference between getting the capability and not.

The counterpoint is honest: a pod occupies a hardpoint that could carry fuel or a weapon, and an external store is aerodynamically and radar-wise less elegant than an internal fit. It is a compromise, but it is a compromise that can be delivered this decade.

A breakdown of the main categories of electronic warfare and what each is for.

Software is the actual product

Viper Shield is described as software-defined and built on commercial off-the-shelf components, and that is the point that decides whether it stays relevant.

Electronic warfare is not a fixed contest. Threat radars change their waveforms; a countermeasure that worked last year can be useless against a software update pushed to an air defence battery. A suite whose behaviour lives in code can be reprogrammed against a new threat in a way that one built around fixed hardware cannot.

Whether that promise holds depends on something no press release covers: how quickly the mission data files behind it can be written, tested and distributed to eight different air forces. That is a bureaucratic problem rather than an engineering one, and it is usually the harder of the two.

Electronic warfare as a continuous contest between emitters, receivers and the people writing the software.

Sources: L3Harris press releases of 3 September 2026 and August 2026, FlightGlobal, The Defense Post, Defense Daily, Air Force Technology, Military Embedded Systems, aeroTELEGRAPH.