Fighter aircraft have forged ahead on the cutting edge of technology since mankind began using them to kill one another with them en masse. This in turn means that fighters have generally been amongst the most expensive and complex war machines of their period, as well as subject to rapid replacement as the pace of development in aerospace technology has literally soared along in the last one hundred and twenty years.
But the vast expense of maintaining fleets of these cutting-edge machines has led to concerns on how to cut their costs while maintaining effectiveness. And one of the attempted resolutions to this that has been fairly consistent in popping up periodically as a potential solution is the concept of the “light fighter”. In essence, the idea is to build an aircraft of as minimal size and complexity as possible yet still retain some comparative combat effectiveness.
The idea really began to gain traction in the 1920s as the rapid development of fighters saw them begin the inevitable march towards greater size, complexity and expense. To be honest, the concept is certainly not without its merits, something that became more appreciated as the cost of fighter aircraft expanded, and it was from the 1950s onwards that the idea of the light fighter really found its place. Aircraft like the Northrop F-5, designed expressly with the recognition that smaller nations didn’t want nor could afford the costs of the latest aircraft being built, proved hugely successful and highly effective.
This was followed in the 1960s and ‘70s with the two major powers, the United States and the Soviet Union, beginning to actively create two-tier fighter systems with the development of aircraft combinations like the F-15 and F-16, the F-14 and F-18 and the MiG-29 and Su-27.
But once again the cost of such advanced aircraft gave many potential buyers pause, with even the supposed “cheap” options, aircraft like the F-16 or French Mirage 2000 still being huge investments. And this led to one country, Switzerland, giving serious thought to not just developing a light fighter for their requirements, but a REALLY light fighter.
Throughout the 1920s and ‘30s the Swiss had built up their own aircraft industry to provide for their own needs. Generally, this had built type’s licensed from other countries, though the Swiss had created their own unique designs such as the EKW C-36.
However, the coming of the jet age had largely meant that, despite spirited attempts to design their own aircraft, the Swiss had been forced to rely on at best building aircraft under license or simply buying outright from other countries. But with the continued expansion in size and costs of modern fighters, in the early 1980s the Swiss Air Force thought they saw an opportunity to perhaps have a crack at building their own aircraft once again. Moreover, that aircraft could potentially suit the Swiss nations own particular defensive needs better than a foreign design.
So in 1981 the ALR was established, which translates into the Aerospace Project Development Group. This aeronautical think tank bought together members of the Swiss Air Force, aero industry and the Swiss Federal Institute of Technology to explore new ideas and how technological advances in the field could be utilised with a view to building a Swiss fighter.
Ultimately, no combat aircraft would come of this, but it did create an intriguing concept aircraft.
The ALR Piranha.
The broad thinking was that the advances in engines, airframe design and composition and precision “smart” weaponry meant that a single airframe was now potentially much more capable than a multiple of earlier generation aircraft. Moreover, instead of leveraging this fact to make fighters bigger and more capable, the Piranha could be smaller but retain comparable combat capability to existing aircraft instead.
And when I say smaller, I mean SMALLER.
Though multiple potential versions of the Piranha were envisaged, the smallest would have had a wingspan of just 6m (19 feet 8in) and a length of just 10.7m (35 feet 2 in). In comparison the F-5E Tiger had a wingspan of 8.13m (26 ft 8 in) and a length of 14.69 m (48 ft 2 in). This aircraft would likely have been subject to replacement in Swiss service had Piranha progressed and users of the Tiger were considered a key potential market, so comparison between these two is particularly apt.
And I know that a bunch of you out there have already been frantically typing that the Piranha is basically a Swiss Gripen. Yes, in essence, and considering that a lot of the Swiss and Swedish air defence considerations are extremely similar that probably isn’t surprising. But again, the Piranha would have been positively tiny even compared to the Gripen, which is marginally bigger than the F-5.
The advantages of such a small aircraft went beyond just the costs of building it. Firstly, it made the Piranha a much harder target to acquire and engage, especially in visual air-to-air combat. In fact, I suspect that in a merged dogfight the Piranha would’ve been a real menace to try and keep track of during hard manoeuvring.
But the aircraft’s tiny size would also make it much easier to disperse and store in protected bunkers, something the Swiss in particular considered a major factor. Their air force was housed in deep caverns for protection and as such space was a real constraint on the numbers and size of aircraft that could be stowed securely.
Plus, the small size might constrain other factors such as weapon and fuel load, but here ALR thought that the new turbofan engines coming into service could help compensate for this. These produced surprising amounts of power in compact and fuel-efficient packages and thinking ahead to potential sales in the future ALR put thought into building multiple variants of the Piranha to meet different needs.
Though all the envisaged Piranha’s shared the same canard delta design with a fly-by-wire control system, the idea was that the new aircraft could be fitted with a range of avionics and engines, indeed with the option of having a single-or-twin engine fit, depending on the customer’s needs.
So, the initial Piranha 1 was a subsonic ground attacker with very limited capability, but subsequent proposed versions became gradually more advanced.
The Piranha 2 was to have Adour turbofans, the same engine that powered the SEPECAT Jaguar and BAE Hawk trainer. Three versions of this were proposed, the -2C, another simplified ground attacker with a non-afterburning engine, and the -2D(1) and 2D(2). These, which differed in having different sized wings, were proposed to have an afterburner variant of the Adour which would have produced 10,000lbf and given the Piranha 2D’s an anticipated top speed of around Mach 1.5.
Then there were the Piranha 4-and 5 which were planned to have twin French Larzac engines or American Garret TFE 1042’s respectively, pushing performance higher, while the final proposed variant, the -6, would have had a single RB 199 MK.104 – the same engine as used on the Tornado ADV. This, producing 16,400lbf with afterburner was expected to propel the tiny fighter to a top speed of Mach 1.9.
And just as with the powerplants, the different models were anticipated to use whatever avionics that best suited the customer. Laser designators and optical targeters were all theorised for ground attack variants of the Piranha, while for the air defence versions proposed radars were the AN/APG-67 from the F-20 Tigershark or the AN/APG-69 which is used on some updated F-5s.
These would have potentially given the Piranha the ability to use not just short range heat-seeking missiles, but also beyond-visual range radar guided missiles such as the AIM-7 Sparrow or the future AIM-120 AMRAAM that as in development. Combined with this would be an integrated gun, either a 27mm or 30mm cannon, and seven hardpoints for ordnance.
Naturally, bombload and fuel would be limited for such a small aircraft, but by using precision guided weapons it was expected that the Piranha would deliver far more “bang-for-its-buck” than aircraft using conventional munitions. Plus, as to its limited range, well, for Swiss Air Force requirements that probably wasn’t too much of a concern, as the country is small and doesn’t deploy outside their own territory.
And anyway, by using modern engines the Piranha would have, it was thought, been comparable in combat range to the sorts of aircraft that it was expected to replace – aircraft like the F-5, the Dassault Mirage III and the MiG-21. These had short combat ranges in comparison to their bigger breathren but did their tasks well enough.
Indeed, it’s notable that all these aircraft are still in service in heavily updated forms because the cost of improving them was less than the cost of replacing them, and they still do their jobs just about well enough some forty years after ALR recognised the need for a replacement for them.
And here is the thing about the ALR Piranha, and it’s a theme we see time and again in military aviation history – ALR were spot on with their idea; they were just too early…and maybe a little extreme on the sizing.
Because today we see a whole host of nations adopting light fighters, generally based on advanced trainers, and these are small, cheap(er) to operate and capable of using advanced weaponry. Indeed, for some nations these new light fighters have become their standard, replacing aircraft like the F-5, the Mirage and the MiG-21.
But as said, the Piranha was an idea both ahead of its time and perhaps a little too extreme. The aircraft saw some development work, progressing to air tunnel testing and to scale models being built and test flown. According to ALR in 1984 they even collaborated with Boeing on potentially setting up a joint venture to build and market the Piranha 6, but this was blocked by the US government.
And ultimately the Swiss government also signalled that they had lost interest and the whole project gradually wound down.
But it does leave a rather intriguing “what-if” aircraft.