Fleet air defence since 1945
From Kamikaze to hypersonic missiles
Article published on Air et Cosmos website 29/06/2022
Beyond the human tragedy, the loss of the Moskva is a terrible blow to the prestige of the Russian Navy. How can a ship designed for anti-aircraft defence, equipped in theory with a set of redundant and complementary systems, and considered until recently to be superior to the Western Aegis/Aster, be hit and, above all, sunk by so few Exocet-class missiles?
In this article, we'll look at how fleet air defence has had to evolve to adapt to new threats since 1945.
The threat since 1945
The birth of guided missiles
The Second World War saw the use of aircraft in anti-ship warfare. The fleet's anti-aircraft defence had to evolve to meet the saturating attacks of dive-bombers, torpedo planes and, especially in the Pacific, kamikazes, which caused enormous losses (some fifty ships).
Air defence was based on radar detection, with 10 to 15 minutes' warning, and several defensive curtains. The first curtain provided air cover for the fleet if aircraft carriers were available. The second curtain was based on medium-calibre artillery to hit targets at medium altitude. The last curtain, which was by far the densest and most ammunition-intensive, was the small-calibre rapid-fire artillery for close-in anti-aircraft defence: 12.7mm and above all the famous 40mm Bofors "Pom pom", which is still used today.
This iron wall, which pilots had to cross to drop their bombs, torpedoes or rockets on their targets, did not allow pilots to project themselves into a long career, as the losses were enormous.
The Japanese, with little regard for the lives of their young pilots, simply replaced their attack aircraft with much faster rocket planes (Okha) to increase the chances of a hit. But there was still no hope of survival for the pilots who guided these early anti-ship missiles until impact. The air supremacy of the US Navy prevented this weapon from making any significant impact.
The Luftwaffe, keen to keep their pilots alive, used its Wunderwaffe with some effectiveness from 1943 onwards on isolated ships (some fifteen ships sunk).
Ruhrstahl's Fritz X guided glider bomb and Henschel's HS 293 marked the first step in another revolution in naval warfare.
These weapons, guided by radio/TV from an aircraft flying less than 10 kilometers from its target, sank the cruiser Roma and damaged several other Allied cruisers before Allied air supremacy made their use impossible.
However the concept of a guided weapon fired from a safe distance was an example for many designers to follow.
INS Eilat, the first victim of Termites
Under the influence of Admiral Gorshkov, the Soviet Navy quickly developed a formidable new anti-ship weapon, and exported them in huge numbers to all its allies. The 2.5-ton P15 Termit missile could be carried in a rack of 4 in small, inexpensive patrol boats, giving countries with no blue water navy sufficient firepower to threaten NATO's surface fleets.
Flying at 30 metres and almost Mach 1, this salvo-fired weapon was extremely difficult to intercept.
On October 21 1967, 3 Egyptian patrol boats fired 4 P15s without even leaving the harbour, to create a tactical surprise, and destroyed the Israeli ship with 3 direct hits.
The Israeli ship designed in 1944 had no defence adapted to this new threat.
For 6 years, the Israeli navy will be preparing its revenge by developing fast, light ships equipped with anti-ship missiles and electronic systems enabling them to detect and jam guidance radars.
The Israeli navy, the smallest branch of Israeli armed forces, had to make up for this affront.
1972 Battle of Đồng_Hới
Meanwhile, a little further to the east, the first major conflict in which a modern air force was pitted against an integrated defence system was taking place. Only one notable event occurred off the coast of Vietnam, when a raid by two or three MiG17s, a simple, rustic aircraft, attacked an American flotilla of 3 ships, 2 of which were equipped with the first-generation anti-aircraft missile, the Terrier.
The US Navy claims to have shot down a MiG and sunk 3 North Vietnamese patrol boats; the North Vietnamese for their part deny any losses.
Both sides agree, however, that the MiGs did damage 2 American ships.
This engagement showed the vulnerability of the ships, due to the lack of effectiveness of this first-generation SAM system, which was incapable of intercepting fast, low-flying targets. The US Navy learned a lesson of humility that day; they will never again come so close to shore without air cover.
1973 The revenge
Having 'stolen' their new ships from the Cherbourg shipyard, the Israeli sailors spent 3 years fine-tuning tactics and weapons for their 500 tons Sha'ar 3 and 4 fast patrol boats.
The Israeli ships, being too small to be equipped with bulky anti-aircraft systems, decided to rely on electronic warfare and small anti-ship missiles. Because of their missile's range disadvantage, they had to avoid being detected and engaged by enemy systems at all costs. They used radar echo amplification technology devices mounted on helicopters and chaff rockets to deceive enemy radar operators.
The Syrians, fooled by the numerous echoes, fired all their missiles at maximum range at fictitious targets.
Once the enemy ran out of missiles, the Israelis could then close in at full speed to fire their Gabriel anti-ship missiles, sinking 2 ships and forcing the third to run aground.
They would use the same tactics with the Egyptian fleet the following day, thus ensuring their control of the seas for the rest of the conflict.
The Israelis have demonstrated the importance of electronic warfare at sea. Chaff, EM detection and jamming, as well as the helicopter's ability to see targets well beyond the horizon. This equipment has become standard on all military vessels worldwide.
This engagement between small ships with first-generation missiles took place at ranges of less than 30 km, while NATO and Red fleet blue water navies’ were beginning to deploy weapons systems with ranges 5 to 10 times greater.
To everyone's surprise, the next major naval battle will not be in the North Atlantic to defend old Europe but to reclaim a small piece of land in the South Atlantic belonging to the British Crown.
Operation Corporate
When Margaret Thatcher asked Admiral Leach, Chief of Staff of the Royal Navy on April 2nd 1982, if they could take the island back he confidently answered:
"Yes we can and we should, because if we do not, or if we pussy-foot in our actions and do not achieve total success, in a few months we shall be living in another country whose word counts for little.",
Margaret Thatcher didn't hesitate another second to put her trust in the First Sea Lord, despite the fact that her entourage gave the operation no chance of success.
The Ministry of Defence, the British Army, the Royal Air Force and even American allies all considered this operation impossible.
Admiral Leach knew that his navy was doomed by budget cuts; his aircraft carriers and a large number of frigates had already been sold to allied countries. He probably saw this as the Royal Navy's last chance to demonstrate its ability to defend the Crown.
In the space of 48 hours, no less than 220,000 tonnes of warships, including 2 aircraft carriers and 23 frigates, together with an air group of 28 Sea Harrier fighters and 165 helicopters, set sail. All this was followed by 68 ships totalling 980,000 tonnes to support the 28,000 British sailors and soldiers.
During the three-week cruise to the South Atlantic, Admiral Woodward, commander of the fleet, had to plan how to neutralise enemy threats with the equipment at his disposal.
The first defensive curtain of his fleet was his submarine force, which could engage the two Argentine surface groups as far away from the fleet as possible. The loss of the cruiser General Belgrano, sunk by HMS Conqueror on May 2, quickly removed any threat from the rest of the enemy fleet. Since the Argentinians had no effective means of hunting nuclear submarines, they ordered all their surface ships to return to port. The Argentine fleet, equipped with Exocet missiles and a light aircraft carrier, was thus neutralised and played no further role in the conflict.
Its second curtain was based on its 28 Sea Harriers, a small subsonic fighter ill-suited for the role of interceptor, but which would prove indispensable against Argentine low-level bomber raids on the amphibious force, thanks to the brand-new AIM 9L Sidewinder missiles that the Americans rushed to deliver to the Royal Navy at the start of the conflict.
The final defensive level was based on ship-to-air missiles, artillery and EW systems. The Royal Navy had 2 generations of long-range missiles in the fleet, the Sea Slug and Sea Dart, capable of ranges of 40 km and 60 km respectively, and two generations of short-range missiles (less than 5 km): the Sea Cat, at the end of its life, and the Sea Wolf, which was very promising (capable of intercepting an artillery shell flying at 800 m/s) but still unreliable.
The amphibious force will use the most modern system available for air defence, Type 42 destroyers for long-range engagement (SeaDart) and Type 22 destroyers for low-altitude engagement with Seawolf. The question that kept Woodward awake at night was whether these systems, none of them were combat proven, were really capable of stopping Argentine air raids and negating the 5 available exocets fitted to the recently delivered Super Étendards.
British air defence officers were well aware of the Exocet's performance. The first warning would come from ESM detection of the radar emissions of the Super Étendards, searching for targets from 60-70 km away. Once fired, the missile flies within 5 meters of the surface at 800 km/h to a predetermined point, where it switches on its radar for final guidance. Because of the speed, altitude and curvature of the earth, ships can only detect the missile less than 2 minutes before impact. To defend itself, the fleet would have to use Israeli tactics, i.e. create as many false targets as possible, thanks to a huge consumption of decoys and helicopters equipped with radar echo amplifiers.
The Argentinian pilots had the opposite vision of this very challenging problem: how to get close enough to the invading fleet and survive this deadly multi-layered defensive death trap, against which they had no fighter escort or electronic protection systems.
Their survival depended solely on their ability to fly very low (15m) and as fast as possible, to avoid detection.
A typical mission for a Dagger or Skyhawk flights was to fly at very low altitude over water or terrain, to avoid enemy fighter patrols and long-range missiles.
With no escort or defensive armament, any interception by Sea Harriers would result in huge losses; 21 Argentine fighters would not come back.
The Sea Harrier quickly earned its nickname the Black Death.
Aircraft that successfully avoided the fighter screens were then engaged by frigates equipped with SeaCat/SeaWolf and all available small to medium-calibre artillery. Some ships were even equipped with laser blinding systems, the effectiveness of which has never been proven.
23 aircrafts were stopped by this final layer of defence. The surviving pilots had only a few seconds to select a target and drop unguided bombs in attack profiles very similar to the torpedo plane pilots of WWII though at near supersonic speed.
It's impossible not to admire the courage of these pilots, who set off on missions with the same armaments as the Stukas of the 40s, against one of the best-equipped and best-trained navies on the planet.
Despite all the odds, they inflicted heavy losses on the Royal Navy, sinking 6 ships and disabling 12 others, 6 of which would probably have been lost if the bomb detonators’ had worked properly.
But the human and material cost was exorbitant! 48 Argentinian pilots fell victim to the British defences, almost half of the attack aircraft involved (Skyhawks and Daggers); an unbearable loss rate that will definitely disqualify any strike at sea without stand-off weapons in the eyes of any commander.
The Argentinians kept the Super Étendard Exocet for attacking the carrier group, but the use of decoys, the layout of the ships and the very limited number of missiles available prevented them from being targeted. Two ships were hit: the Sheffield, an anti-aircraft frigate taken by surprise, and the Atlantic conveyor cargo transformed into a helicopter carrier.
The combination of aircraft and anti-ship missiles became a key weapon against which all navies had to find a response.
Developments since 1982
The Falkland was the first conflict where modern warships had to defend themselves against fighters and missile attacks. There were many lessons learned it had a profound influence on the evolution of world navies over the last forty years.
The importance of air cover
Cap F14
A surface ship has a radar detection volume limited by the Earth's curvature; a fighter or missiles flying at low altitude cannot be seen beyond 35-40 km from the ship. A surface group equipped with Awacs-type aircraft can create a detection bubble with a radius of over 500 km, and vector interceptors far away from friendly ships, well beyond the detection and engagement zone of the enemy strike package.
A fleet under the protection of an AWACS and fighters will allow all friendly assets to remain electronically silent denying the enemy a good situational awareness. But it will keep all the members of its group informed of their own positions and of any inbound threats thanks to a networked environment (link 11-16 etc.)
Cap F14
Today, a modern aircraft carrier group can detect a target with an Awacs or a drone and order a plane or a ship to engage, without the latter switching on its radar. This collaborative engagement capability is a real revolution in fleet defence, enabling us to take our adversaries by surprise.
After the Falklands, the effectiveness of the Sea Harrier/Sidewinder combination was never again called into question (26 shots; 18 aircraft shot down). Without them, 22 more Argentinian aircrafts would have had an opportunity to sink more Royal Navy Ships.
Subsequently, the Royal Navy commissioned 2 extra aircraft carriers for the Sea Harriers, which will be eventually equipped with high-performance Amraam radar-guided missiles. They will also transform a number of helicopters into mini AWACS.
If, in 1982, the Royal Navy still had at its disposal the two 45,000-ton aircraft carriers it scrapped in the 70s, equipped with F4G Phantom supersonic fighters capable of flying twice as fast, twice as far and with 4 times as many missiles as the Sea Harrier, this war simply wouldn't have happened, the Argentinians would never have dared to invade against such a threat.
Improved engagement capabilities of surface-to-air missiles
Aegis ships in action
Today, an air raid is considered suicidal if it has to approach within 60-80 km of a group defended by modern ships equipped with several hundred SAMs. Fortunately, this is no longer one of the missions envisaged by any pilots. They now rely on long-range anti-ship weapons.
Modern SAM systems can handle dozens of targets simultaneously (Aegis, PAAMS, S300F). They are also optimised to handle manoeuvring missiles moving at high speed (Mach 2+).
The strength of an Aegis-type system lies in the centralisation of the firing decision by a computer, which feeds on information supplied by all the sensors on the networked ships, aircraft and ground stations. Firing orders are redistributed to the same platforms according to the weapons available to them.
This highly automated system is, of course, supervised by humans, but full automation is essential in the event of a saturating attack by ever-faster missiles, where the time between detection and impact is counted in tens of seconds.
Point defence
The final defensive curtain was also considerably strengthened by the introduction of 20 or 30-mm Phalanx or Goalkeeper radar-guided guns with high rates of fire (80 to 100 rounds per second) or very short-range missile systems (Mistral, RAM, Seaceptor). Swarm attack by cheap drones or fast RIBS has become a threat in recent years,
Enhanced survivability
Warships are no longer equipped with armour plates to deflect AP shells; their survival depends on their ability to survive fires and floods in the event of impact.
The loss of HMS Sheffield, due to failed fire equipment and insufficient crew training in firefighting, was an electroshock. A few years later, the USS Stark, a frigate identical in size to the Sheffield, survived the impact of 2 Exocet missiles fired by an Iraqi Falcon. The crew succeeded in controlling the fires thanks to effective procedures and equipment (oxygen-suppressing Halon gas, anti-fire sprays, etc.).
Compartmentalisation, improved construction materials, reduction of radar and infrared signatures, and fire-resistant ammunition are just some of the developments that further enhance the survivability of ships.
Notable incident since 1982
Several warships, each isolated, were the victims of missile attacks. Two notable incidents were the 2006 attack on the Israeli corvette INS Hanit, which was hit by a missile fired by Hezbollah, and the USS Stark, which was hit by 2 Iraqi Exocets.
In both cases, the ships were hit because the defence system was not active; both survived.
New threats, old threats...
The Chief of Staff of the French Navy, in a recent speech to a new generation of graduating officers, stated that they belonged to a generation that would most probably experience high-intensity naval warfare.
With this in mind, crew training and research budgets need to be stepped up to maintain our technological edge, which is real but slowly eroding.
But the centrepiece of any blue water navy is still the aircraft carrier.
Its usefulness is regularly called into question. Expensive and supposedly highly vulnerable, its offensive capabilities remain unrivalled to this day. Its air group is also a fleet's best defence system, able to neutralise enemy raids long before they become a threat, even with new exotic weapons (missiles or Rail guns).
The British have not forgotten the indispensable role they played in 1982, nor should France.
Sources
Air defence artillery in combat =>Mandeep Singh
One hundred days => Admiral sandy Woodward
Harpoon data annex 1990
La guerre des malouines => Charles Maisonneuve &Pierre Razoux
