A “STUPID” Mistake Is Making the F-35 UNSTOPPABLE

The Lockheed Martin F-35 Lightning II is a miracle of modern engineering. Combining supersonic speeds, advanced stealth technologies and an unprecedented sensor network, it's more of a flying supercomputer than a conventional fighter jet. But two of the three versions of this fighter, the F-35B and C to be precise, have always had a large and quite obvious flaw, visible from the very first glance. A bathtub-sized cannon bolted to the aircraft's belly. That cannon slows down the F-35's acceleration and expands its radar cross-section, harming both its agility and stealth capabilities. Yet somehow, the US military has turned what seems to be a massive mistake into the aircraft's deadliest advantage. To understand how and why this happened, we must first take a step back. Several decades back, in fact, to the days of the Vietnam War. In the mid-1960s, the McDonnell Douglas F-4 Phantom II was one of the most prominent and prevalent aircraft in disguise over North Vietnam. With nine external hardpoints, the F-4 had the ability to carry up to 18,650 pounds or 8,500 kilograms of weapons, including various air-to-air and air-to-surface missiles. It did not, however, originally come with its own internal gun, though some variants later carried external gunpods. It didn't need one, according to the engineers who designed it, because it had radar-guided Sparrow missiles and heat-seeking Sidewinders, and they should be able to eliminate any targets before the enemy could even think about fighting back. At least, that was the theory. In practice, it didn't quite work out that way. The A-9B Sidewinder, for example, was a far cry from the highly precise fire-and-forget air-to-air missiles of the modern era. It had numerous limitations, like a maximum effective range of just three nautical miles or the fact that it could only lock onto targets' exhausts when directly behind them. The Sidewinder's Seeker head also had a relatively low angular tracking rate of just 11 degrees per second, so it was almost entirely ineffective at targets performing hard evasive maneuvers. It also struggled with the sun and clouds, with its Seeker sometimes mistaking them for enemy targets. And all these issues added up, with the Sidewinders of the 60s having relatively low kill probabilities of around 16%. The AIM-7D Sparrow wasn't any better. The air-to-air missile had a minimum engagement range of between 3,000 and 5,000 feet, and every time a shot was fired, it was up to the pilot to keep their radar locked onto their target for the entire duration of the missile's flight. That wouldn't have mattered much in safe, uncontested airspace, but with enemy fighters in the air and potential danger lurking behind every cloud, it was incredibly risky for these pilots to simply fly in straight lines and hope for the best as their missiles drew nearer to their targets. As a result, the kill probability of the earliest Sparrow missiles used in Vietnam was less than 10%. On top of that, the rules of engagement meant that US pilots had to visually identify any enemy aircraft before firing on it, so they couldn't take advantage of the long-range nature of their weapons. They were compelled to get in close and put themselves at greater risk before even being authorized to lock on. As a result, F-4 pilots often found themselves in dogfight situations, but without the guns necessary to win those battles. On top of that, many of those pilots hadn't undergone any sort of extensive air combat maneuvering training, so they often had neither the skills nor the equipment needed to survive. They'd often have to slow down their aircraft to subsonic speeds and do their best to get behind their enemies, but were often too close to actually fire their missiles with any real hope of a successful impact. It's no wonder then that many pilots complained about the absence of cannons on these planes. US Navy pilot John Cheshire, for example, said the lack of an internal gun was the biggest mistake on the F-4, adding, Bullets are cheap and tend to go where you aim them. I needed a gun, and I really wish I had one. Marine Corps General John Daly agreed, noting that, Everyone in RF-4s wished they had a gun on the aircraft. Eventually, those calls became too loud to ignore. The Phantom was redesigned, with an external gun pod initially bolted on the fuselage before the entire airframe was redesigned with an internal M61 Vulcan cannon. From that moment on, America's military aircraft engineers vowed never to make the same mistake again. Even though there haven't been any recorded air-to-air gun kills for several decades, and world-leading defense contractor Lockheed Martin claims that the era of the dogfight is over, cannons are still listed in every operational requirements document. Whenever a new fighter is being designed, engineers are always told to make space for some sort of gun, even though it may never actually be fired. Why? Because it's an invaluable deterrent. The very presence of a cannon effectively denies the enemy the one option it would have to counteract missiles, getting up close and personal. It's not about dealing damage or scoring kills, it's about preventing your opponent from even thinking about getting too close. So, even when the finishing touches were being put on the F-35's design in the early 2000s, the requirements of the Joint Striker-Fighter Program dictated that it should carry a gun, and not just any gun, but one that was capable of achieving a kill probability of 35% against lightly armored vehicles at 9,000-foot slant range. That gun was the GAU-22A, a 25mm Gatling gun produced by General Dynamics Ordnance and Tactical Systems and based on the GAU-12-U design. Weighing in at 240lbs or 104kg and capable of firing up to 3,300 rounds a minute, this is a heavy-duty piece of equipment, and engineers had to find a way to fit it into one of the most advanced stealth fighter designs the world has ever seen. You don't need to be a military engineer to realize that the most logical option would be to somehow fit this weapon inside the body of the plane. That's exactly what designers did with the F-22 Raptor, for example, which conceals its gun inside its wing root. If and when the cannon needs to fire, a trap door opens up, and 100 rounds per second are unleashed against any target in view before the door seals shut, preserving the stealthy and aerodynamic nature of the airframe. For the F-35A, the designers more or less did the exact same thing, hiding the GAU-22A inside the fuselage. With the other two variants, however, the F-35B and C, it wasn't quite so easy, for one simple reason. There wasn't enough room. The F-35B is a short take-off-vertical-landing Stovall variant used by the Marines. In order to be able to take off from only small strips of land, it has a lift fan inside its body, along the three-bearing swivel module, which takes up a large amount of space, leaving little left over, certainly not enough to house a relatively bulky Gatling gun. The F-35C, meanwhile, is the US Navy's carrier jet and comes with both reinforced landing gear and close to 20,000 pounds, 9,000 kilograms of fuel, all stored internally, which is more than any other F-35 variant. Again, that means there's no room left for the GAU-22A. The only option left, therefore, was to position the gun externally, bolting it to the base of the aircraft's body, not behind a trapdoor or stealth panel, but right out in the open, wrapped in a huge carbon-fiber pod for protection. Two of those carbon-fiber pods exist, and both are made by a Danish company called Terma. There's the GPU-9A for the F-35B and the GPU-8A for the F-35C. On the surface, very little makes sense about this design choice. Not only does it look clumsy and awkward to have a huge bathtub-sized structure, tacked onto the bottom of the state-of-the-art stealth aircraft that cost around $110 million per unit, but the external gun pod has also been proven to negatively affect the fighter's performance. It disrupts the jet's aerodynamic design, adding air resistance and drag to what was once a smooth, sleek, and perfectly sculpted airframe. Data shows that the F-35A needs an extra 8 seconds to accelerate from speed to Mach 0.8, break the sound barrier, and reach Mach 1.2, otherwise known as the fighter's transonic acceleration, compared to the program's original performance estimate. The F-35B, meanwhile, with its external GAU-22, spends an extra 16 seconds on transonic acceleration, while the F-35C, which has the added weight of an external Gatling gun, plus the largest wings and most fuel, needs a whopping 40 seconds, five times more than the F-35A. Yet, despite these obvious issues, the external gun is far more valuable and beneficial for the US military than it first appears. But before we explore why, if this is the kind of insight you want more of, make sure you're subscribed to the Military Show. We break it down like this every week. To understand why the external gun of the F-35B and C works better than the internal cannon of the F-35A, we have to get to know this weapon a little better. The GAU-22A is a 4-barrel, 25mm Gatling gun. It's bigger than the 20mm Vulcan cannon seen on the likes of the F-22 and F-16, but more compact than the 30mm Avengers on A-10 Thunderbolt IIs, also known as Warthogs. It fires 55 rounds a second, at speeds of 3,560 feet per second, which is more than three times the speed of sound, and the cannon produces a sizable recoil force of around 3,700 pounds, or almost 16,500 newtons. That's about the same recoil as having a small jet engine pushing the airframe backwards every single time the pilot pulls the trigger. And this is where the beauty of the external pod begins to shine, because the pod is mounted from the centerline station, with the hardpoint situated right underneath the spine of the fighter. It's directly connected to the F-35's main longitudinal structural beam, which is the single most stable mount point on the entire airframe. That means that when the external cannon fires, all 3,700 pounds of its recoil force is isolated from the rest of the aircraft. That force passes through the hardpoint into the strong structural beam, rather than impacting the aircraft's composite exterior, stealth coatings, or internal components. In other words, the gun still kicks with every shot fired, but the pod absorbs that kick, so the actual airframe barely even feels it. To understand why that's so important, we have to compare the external pod design to the internal cannon seen on the F-35A. On that variant, the internal gun sits in a recess in the left side of the fuselage, behind a flush door. That kind of design can work. The F-22, for example, has an internal cannon, which is cleverly placed so that the recoil force is absorbed by the wing root. But that's not the case in the F-35A. There, every time the weapon fires, its recoil force passes directly into the composite skin of the aircraft's chine longeron, the critical structural beam that runs along the sharp edges of the aircraft's fuselage. That composite skin wasn't built to cope with such intense forces, so it starts to crack. The stealth skin of the F-35A, an integral part of its design, begins to break. Because of this, the usage of F-35A cannons was tightly scrutinized for years as engineers worked through concerns surrounding vibration, accuracy, and potential wear on the aircraft's stealth coating. Pilots still conduct live fire training exercises with the guns, but the military has taken extensive precautions to minimize unnecessary stress and damage to the aircraft's skin. And that's not the only problem. For years, the gun on the F-35A was also flagged in the Pentagon's annual evaluations as being inaccurate. From 2019 through to 2023, it failed to meet operational accuracy requirements. Even from 2024 onward, it's still technically classified as lacking in accuracy, though it has been deemed operationally effective. The external cannons on the F-35B and C, meanwhile, have none of these issues, thanks to their design and placement. The recoil force doesn't impact the airframe in any negative way, and with no risk of cracking or structural damage, there's no need for any restrictions regarding how, when, or where these guns are used. On top of that, the external guns have also been proven to be much more accurate. That's so important, because these fighters don't actually carry that many rounds. They use the PGU-32U semi-armor-piercing high-explosive-incendiary tracers, or SAPE-Ts, capable of blasting through light armor and detonating within their targets, burning them from the inside out. Each jet is equipped with 220 rounds in total, and a specialized controller limits the size of each burst to between 30 and 50 rounds. That means that each time the pilot pulls the trigger, approximately 40 rounds are fired, giving them only 5 or 6 trigger pulls before they run out of ammo. That's not a large number, so it's vital to ensure that every round counts and as many shots hit their targets as possible. Thankfully, the F-35 was designed with next-level accuracy in mind. In this jet, the pilot doesn't aim with their eyes, but with the aid of a special helmet-mounted display system, HMDS, that projects targeting data directly onto their visor. F-35s also use ESA radars to find and track targets, increasing the cannon's accuracy even more. That matters, because it unlocks any invaluable way for US forces to attack their enemies and achieve their objectives, the Lightning Carrier concept. This effectively involves transforming amphibious assault ships, like the USS Tripoli, into light aircraft carriers by embarking up to 20 F-35B stealth jets on each one. These rapid-response carriers can then provide almost instant fire support to Marines as and when required. Imagine troops are on the ground and pushing towards their objectives but need fire support to help suppress the enemy and allow them to advance. There are no early warning aircraft or electronic warfare planes like EA-18G Growlers in the sky around them. Nor can they rely on the likes of A-10 Warthogs, which need huge runways to take off and land. With a Lightning Carrier positioned nearby, a dozen or more F-35Bs can be in the air in a matter of seconds, ready to lend a hand, save lives, and accelerate the American advance, using their highly accurate external cannons to lay down radar-guided precision strikes from above without even needing to break through the clouds. And we haven't even got to the best and biggest advantage of the external pods of the F-35B and C. They don't necessarily need to hold cannons at all. Terma, the Danish company that makes the pod's carbon-fiber shells, developed a new variant called the Multi-Mission Pod, or MMP. Using the same outer mold as the standard gun pod, with the exact same shape and aerodynamic profile, the MMP introduces a whole host of new opportunities. Instead of a gun, it can carry an electronic warfare jammer, for example, capable of cutting enemy communications, imbuing the F-35 with the abilities of the EA-18G Growler. The MMP can also be equipped with an intelligence, surveillance, and reconnaissance ISR sensor package, allowing it to obtain even more intelligence than it already can with its systems. Alternatively, it could be fitted with a directional data link, turning it into a drone swarm commander capable of controlling and guiding an entire formation of Collaborative Combat Aircraft, CCAs. The MMP could even potentially support future directed energy or laser-based systems, allowing an F-35B or C fighter to one day counter enemy drones in ways that seem more like science fiction than modern warfare. This is the true power and almost limitless potential of the external pod design. It allows the F-35, which is already arguably the most versatile fighter ever created, to take on even more loadouts and confront even more diverse objectives simply by swapping out one pod for another. The core of the airframe remains the same. The size of the pod too remains the same. There's no difference in the aircraft's drag, speed, or overall performance, even as it changes from an EW setup to ISR, direct energy, or even the classic Gatling gun. With its gun built into its body, the F-35A isn't capable of any of these configurations, rendering it far less flexible and useful from a modern military perspective than its BNC siblings. Because the true value of the gun pod isn't the weapon it holds, but the space it creates. The F-35A is destined to always have this internal cannon, which restricts its viability and constricts its usefulness for missions to come. The BNC models, meanwhile, offer so much more. They give Marines and the Navy options. They empower these forces to ask the question, what does this mission need, before every deployment, and decide on the ideal equipment every time, be it a data link, ISR sensors, or something else entirely. When they first decided to attach an external cannon to the F-35 BNC, engineers were solving a problem the only way they could. Initially, it looked like an awkward solution, destined only to degrade the F-35's aerial performance. Over time, however, that awkward add-on turned out to be one of the most valuable pieces of the plane's design. The flaw became the feature, and inadvertently made these fighters more flexible, powerful, and future-proof than anyone ever imagined. Now you can learn more about how the US military is always evolving, breaking new ground, and finding innovative and exciting ways to project power in this video, which looks at the Trump-class battleships which are set to change the face of naval warfare like never before. Alternatively, check out this video to learn about how the US Navy has been testing laser weapons on aircraft carriers to make them more survivable and more lethal in the age of drone warfare. And finally, don't forget to subscribe to The Military Show for more insights and analysis just like this.