My last post summarised the ins and outs of the missile weaponry used by most modern air forces today, and the impact that this had on fighter technology with the development of the interceptor and fighter-bomber as separate classes. This technology was flashy and rose to prominence during the Korean war, but the powers-that-be still used large bomber aircraft during that conflict and were convinced that carpet bombing was the most effective strategy for a large-scale land campaign. And who knows; if WWIII ever ends up happening, maybe that sheer scale of destruction will once again be called for.
However, this tactic was not universally appreciated. As world warfare descended ever more into world politics and scheming, several countries began to adopt the fighter-bomber as their principle strike aircraft. A good example is Israel, long-time allies of the US, who used American fighter-bombers early on during the 1970s Middle East conflict to take out the air bases of their Soviet-backed Arab neighbours, giving them air superiority in the region that proved very valuable in the years to come as that conflict escalated. These fighters were valuable to such countries, who could not afford the cost of a large-scale bombing campaign; faster, precision guided destruction made far better fiscal sense and annoyed the neighbours less when they were parked on their doorstep (unless your government happened to be quite as gung-ho as Israel’s). Throughout the 1960s, this realisation of the value of fighter aircraft lead to further developments in their design; ground-assault weapons, in the form of air-to-surface missiles and laser-guided bombs, began to be standard equipment on board fighter aircraft once their value as principle strike weapons was realised and demand for them to perform as such increased. Furthermore, as wars were fought and planes were brought down, it was also realised that dogfighting was not in fact a dead art when one’s opponents (ie the Soviet Union and her friends) also had good hardware, so maneouvreability was once again reinstated as a design priority. Both of these advances were greatly aided by the rapid advancements in the electronics of the age, which quickly found their way into avionics; the electronic systems used by aircraft for navigation, monitoring, and (nowadays) help flying the aircraft, among other things.
It was also at this time that aircraft began experimenting with the idea of VTOL: Vertical Take Off and Landing. This was an advantageous property for an aircraft to have since it limited the space it needed for its take off and landing, allowing it to land in a wider range of environments where there wasn’t a convenient long stretch of bare tarmac. It was also particularly useful for aircraft carriers, which had been shown during WW2’s battle of Midway to be incredibly useful military tools, since any space not used for runway could be used to carry more precious aircraft. Many approaches were tried, including some ‘tail-sitting’ aircraft that mounted onto a vertical wall, but the only one to achieve mainstream success was the British Harrier, with two rotatable engine vents that could be aimed downwards for vertical takeoff. These offered the Harrier another trick- it was the only aircraft with a reverse gear. A skilled pilot could, if being tailed by a hostile, face his vents forward so his engines were pushing him in the opposite direction to his direction of travel, causing him to rapidly slow down and for his opponent to suddenly find himself with an enemy behind him eyeing up a shot. This isn’t especially relevant, I just think it’s really cool.
However, the event that was to fundamentally change late 20th century air warfare like no other was the Vietnam war; possibly the USA’s biggest ever military mistake. The war itself was chaotic on almost every level, with soldiers being accused of everything from torture to drug abuse, and by the mid 1960s it had already been going on, on and off, for over a decade years. The American public was rapidly becoming disillusioned with the war in general, as the hippy movement began to lift off, but in August 1964 the USS Maddox allegedly fired at a couple of torpedo boats that were following it through the Gulf of Tonkin. I say allegedly, because there is much speculation as to the identity of the vessels themselves; as then-president Lyndon B. Johnson said, “those sailors out there may have been shooting at flying fish”. In any case, the outcome was the important bit; when (now known to be false) reports came in two days later of a second attack in the area, Congress backed Johnson in the Gulf of Tonkin Resolution, which basically gave the President the power to do what he liked in South-East Asia without making the war official (which would have meant consulting the UN). This resulted in a heavy escalation of the war both on the ground and in the air, but possibly the most significant side-effect was ‘Operation Rolling Thunder’, which authorised a massive-scale bombing campaign to be launched on the Communist North Vietnam. The Air Force Chief of Staff at the time, Curtis LeMay, had been calling for such a saturation bombing campaign for a while by then, and said “we’re going to bomb them back into the Stone Age”.
Operation Rolling Thunder ended up dropping, mainly via B-52 bombers, a million tonnes of bombs across North Vietnam and the Ho Chi Minh trail (used to supply the militant NLF, aka Viet Cong, operating in South Vietnam) across neighbouring Cambodia and Laos, in possibly the worst piece of foreign politics ever attempted by a US government- and that’s saying something. Not only did opinion of the war, both at home and abroad, take a large turn for the worse, but the bombing campaign itself was a failure; the Communist support for the NLF did not come from any physical infrastructure, but from an underground system that could not be targeted by a carpet bombing campaign. As such, NLF support along the Ho Chi Minh continued throughout Rolling Thunder, and after three years the whole business was called off as a very expensive failure. The shortcomings of the purpose-built bomber as a concept had been highlighted in painful detail for all the world to see; but two other aircraft used in Vietnam showed the way forward. The F-111 had variable geometry wings, meaning they could change their shape depending on the speed the aircraft was going. This meant it performed well at a wide variety of airspeeds, both super- and sub-sonic (see my post regarding supersonic flight for the ins and outs of this), and whilst the F-111 never had the performance to utilise them properly (since it was turboprop, rather than purely jet powered) the McDonnell F-4 Phantom did; the Phantom claimed more kills than any other fighter aircraft during Vietnam, and was (almost entirely accidentally) the first multi-role aircraft, operating both as the all-weather interceptor it was designed to be and the strike bomber its long range and large payload capacity allowed it to be.
The key advantage of multi-role aircraft is financial; in an age where the massive wars of the 20th century are slowly fading into the past (ha, ha) and defence budgets are growing ever-slimmer, it makes much more sense to own two or three aircraft that can each do five things very well than 15 that can only do one each to a superlative degree of perfection. This also makes an air force more flexible and able to respond faster; if an aircraft is ready for anything, then it alone is sufficient to cover a whole host of potential situations. Modern day aircraft such as the Eurofighter Typhoon take this a stage further; rather than being able to be set up differently to perform multiple different roles, they try to have a single setup that can perform any role (or, at least, that any ‘specialised’ setup also allows for other scenarios and necessities should the need arise). Whilst the degree of unspecialisation of the hardware does leave multirole aircraft vulnerable to more specialised variations if the concept is taken too far, the advantages of multirole capabilities in a modern air force existing with the modern political landscape are both obvious and pressing. Pursuit and refinement of this capability has been the key challenge facing aircraft designers over the last 20 to 30 years, but there have been two new technologies that have made their way into the field. The first of these is built-in aerodynamic instability (or ‘relaxed stability’), which has been made possible by the invention of ‘fly-by-wire’ controls, by which the joystick controls electronic systems that then tell the various components to move, rather than being mechanically connected to them. Relaxed stability basically means that, left to its own devices, an aircraft will oscillate from side to side or even crash by uncontrollable sideslipping rather than maintain level flight, but makes the aircraft more responsive and maneouvrable. To ensure that the aircraft concerned do not crash all the time, computer systems generally monitor the pitch and yaw of the aircraft and make the tiny corrections necessary to keep the aircraft flying straight. It is an oft-quoted fact that if the 70 computer systems on a Eurofighter Typhoon that do this were to crash, the aircraft would quite literally fall out of the sky.
The other innovation to hit the airframe market in recent years has been the concept of stealth, taking one of two forms. Firstly we consider the general design of modern fighters, carefully designed to minimise their radar cross-section and make them less visible to enemy radar. They also tend to shroud their engine exhausts so they aren’t visually visible from a distance. Then, we consider specialist designs such as the famous American Lockheed Nighthawk, whose strange triangular design covered in angled, black sheets of material are designed to scatter and absorb radar and make them ‘invisible’, especially at night. This design was, incidentally, one of the first to be unflyably unstable when in flight, and required a fly-by-wire control system that was revolutionary for that time.
Perhaps the best example of how far air warfare has come over the last century is to be found in the first Gulf War, during 1991. At night, Nighthawk stealth bombers would cross into Hussein-held territory to drop their bombs, invisible to Hussein’s radar and anti-aircraft systems, but unlike wars of old they didn’t just drop and hope at their targets. Instead, they were able to target bunkers and other such fortified military installations with just one bomb; a bomb that they could aim at and drop straight down a ventilation shaft. Whilst flying at 600 miles an hour.