When Argentina invaded the Malvinas Islands in April 1982, A British Naval Task force was dispatched to the South Atlantic to recapture them. The Argentine Navy had no anti-submarine capability and so was effectively out of the war due to the presence of British Nuclear-powered submarines in the region. The main threat to the British flotilla came from the Argentine Air force. Of particular concern were the newly acquired Exocet anti-ship missiles. These French-made sea-skimming missiles were known to be highly effective and hard to defend against. The Argentine Super Etendard was known to be capable of firing the missiles. Operating from the Rio Grande Airbase on the Argentine mainland and able to reach the British task force, it was not long before they began to mount attacks.
When HMS Sheffield was hit and disabled by an Exocet, fear arose within the task force and at home that the Exocet could cause an humiliating defeat. The British believed that Argentina had around 5 Exocets in its Arsenal. If just one hid one of the 2 carriers in the task force, the war might be lost.
To counter this threat, the British Secret Services, the SAS and the SBS were called in.
MI6 Operations
Whilst plans were drawn up to neutralize the existing missiles in the Argentine inventory, MI6 were tasked with ensuring that Argentina could not get their hands on any more. Posing as black market weapons dealers, British agents endeavored to buy up all the Exocets on the open and black market. The agents also offered black market exocets to Argentineans in order to waste their time and resources on wild goose chase to buy them.
Operation Mikado
Map of Tierra del FuegoB Squadron of the 22nd Special Air Service were ordered to draw up plans to destroy the exocets, and the planes that could deliver them on their airbase on the Argentine mainland. Brigadier Peter de la Billiere, the then Director, Special Forces, inspired by the Israeli operation at Entebbe, proposed that the SAS perform a tactical landing and assault of an Argentine air base. A plan was subsequently devised for B Squadron to fly in 2 C130 Hercules of RAf Special Forces Flight (47 Sqn) directly from Ascension Island onto the Argentine Rio Grande airbase at Tierra del Fuego. Once on the ground, the 60 or so SAS men would assault the airfield, destroying any aircraft and Exocets present. They would also storm the Officer's mess, taking out the pilots. Following the attack, the SAS would then escape and evade to friendly Chile, either on the C130s, if they survived, or on their own.
Before the attack would go in, a preliminary reconnaissance mission, code named 'Operation Plum Duff' was launched. A small SAS team boarded a stripped down Royal Navy Sea King Mark IV which flew from the Task Force towards the Argentine Mainland. The plan was to put the SAS team ashore who would then march to the Rio Grande air base, put in an OP and send back intel on the defenses. The Sea King barely had enough fuel to reach the mainland and the 3-man air crew, from 846 RNAS, knew this was a one way mission.
The Sea King reached the Argentine coast without being detected but was soon enveloped in fog. 7 miles short of the intended drop-off point, and with the air crew and the SAS arguing over navigation, the Sea King headed for Chile where it landed, a few kilometers over the border. The SAS patrol decided to attempt to complete the mission, moving off on foot towards Argentina. The Sea King crew subsequently attempted to sink the helicopter in a lake but was unable to do so. They instead set the helicopter on fire on the lake's shore and then preceded to implement an escape and evasion plan. When the burnt out Sea King was subsequently found by the Chileans, the MoD tried to cover up the real purpose of the mission by claiming that the Sea King had suffered mechanical difficulties whilst on an anti-submarine patrol and had to make an emergency landing in Chile. Meanwhile, the SAS reconnaissance mission was eventually canceled.
note: for more info on 'Pulm Duff', see Special Forces Pilot: A Flying Memoir of the Malvinas War by Colonel Richard Hutchings, the Royal Marines pilot of the Sea King used to insert the SAS.
Whilst Plum Duff was underway, B Squadron began practicing for the assault operation, code named 'Operation Mikado'. Dry runs against British airfields began to highlight problems with the plan. The large C130s would appear on the target bases;s radar screens, giving the defenders ample time to prepare to repel the attack. This was true even with the C130s flying at tree-top level. To land on the runways, the lumbering cargo planes would have to slow to around 100 knots, making them easy pickings for AAA cannon or surface to air missiles. The Argentines might also simply block the runways with vehicles.
Another problem was that a lack of on-site intel would mean that there would be no guarantee that the Super Etendards or the Exocets would even be at Rio Grande when the assault force arrived. The SAS would also have no idea where the Exocets were kept or even where the pilot's mess was situated.
It soon dawned on both the SAS and the Thatcher administration that Operation Mikado would most likely fail which would have been a propaganda disaster for the British. The mission was duly scrubbed.
But still the threat from the Exocet remained., and British losses mounting. The SAS prepared to put in a plan B. Another SAS team planned to insert onto Tierra Del Fuego on gemini inflatables launched from the deck of Royal Navy submarine HMS Onyx, surfaced off the coast. The SAS men planned to sneak onto the air base, placing explosives on the parked planes, Exocets and pilot's mess. They would then escape on foot to Chile.
Before the plan could be carried out, the Argentineans surrendered at Puerto Argentino and the war was over. It later transpired that Rio Grande was defended by 3 battalions of Argentine Marines. Any SAS attack on the air base would most likely have ended in failure.
SBS Operations
In ex-SBS operator Duncan Falconer's memoirs, First into Action, the author describes how the Special Boat Service were involved in the effort against the Exocet. When MI6 discovered that a shipment of Exocets bound for Argentina were onboard a cargo ship moored in a foreign harbor, the SBS were tasked with destroying it. SBS divers were to swim into the harbor and place limpet mines on the ship's hull with the aim of sinking it. The mission was apparently called off at the last minute when it looked as if the campaign on the islands was drawing to a close and it was calculated that the missiles would not reach Argentina in time to be of help to the Argentineans.
It's also been reported that the SBS would have piloted the Gemini inflatables carrying the SAS strike team for the aborted attack on the Rio Grand base, outlined above.
