UK SOF in the Falklands War: Operation Plum Duff, we’re raiding Argentina

“Action stations! Action stations! This is not a drill!” was the only alert the duty officer of HMS Sheffield managed to give before the impact.

The warning came too late.

Seconds later, an Exocet missile, fired by a sea-skimming Argentinian aircraft, rammed the ship’s starboard side, hitting it between the galley and the forward engine room. An inferno of flame and smoke quickly engulfed the vessel. The order to abandon ship soon came.

Ultimately, the empty destroyer would sink six days later, May 10, while being towed away. Twenty men died. The Exocet had just made its deadly introduction.

A French-built anti-ship missile, the Exocet can be fired from sea, air, and land. At the start of the war, the British knew that the Argentinians possessed at least five Exocets and five Super- Etendard aircraft that could fire them.

With Sheffield’s burning hull a testament of the missile’s destructive capabilities, Rear Admiral Woodward, the Commanding Officer of the Naval Task Force, and his military and political superiors back in Britain urgently sought ways to counter this lethal threat.

If any of the two aircraft carriers, HMS Hermes and HMS Invincible—which were the actual targets the day Sheffield was attacked—were sunk, the Task Force would lose its vital air cover, and the landings would have to be aborted.

A humiliating defeat loomed ominously.

The British reckoned that the aircraft were based either in Rio Gallegos or Rio Grande. The former was farther north, and thus the more unlike option; the latter, located in Tierra del Fuego, in the south part of Argentina, and approximately 400 miles from the Falklands, was judged, correctly, to be the staging area wherefrom the Argentinian aircraft, with their deadly payloads, launched.

Interestingly, the marine officer in charge of defending Rio Grande airbase had participated in several exchange programs in Britain, and not only understood how the British military apparatus operated but also knew the capabilities and achievements of the SAS and SBS.

With the outbreak of hostilities, he thus, shrewdly fortified his airbase against a Special Forces threat. All in all, Rio Grande was guarded by no less than a brigade of marines, with numerous anti-aircraft weapons and shoulder-fired SAM missiles at their disposal.

Not being privy to the defensive preparations of the Argentines, the British commanders hatched their plans. After a hasty debate, a special forces raid prevailed as the best option.

Enter the SAS.

The SAS commanders in Hereford came up with a quite remarkable and true to their motto, “Who Dares Wins,” plan: Operation Mikado would be an Entebbe-style raid, wherein two specially configured C-130s would force-land the troopers of SAS B Squadron, who would then storm the base destroying the aircraft and the missiles, and killing the pilots—and everything before afternoon tea!

This dashing scheme had a slight flaw since no one had the slightest clue about the Rio Grande airbase: where the aircraft were parked—if they were even there—where the missiles were stowed, where the pilots slept, who and what defended the base?

No one could provide a sufficient answer to these vital, for the success of such an audacious mission, questions. A reconnaissance patrol would have to be inserted first. The reconnaissance operation was named Plum Duff.

It envisioned two separate SAS recce patrols of four men each. One would reconnoiter the Rio Grande airbase and the other the Rio Gallegos—to confirm that the planes and missiles weren’t there.

Helicopter was chosen as the method of insertion—the submarine option was discarded because the only conventional submarine capable of performing the mission, HMS Onyx, was still miles away to the north; a land insertion from nearby Chile was also rejected because of legalities; and finally, the parachute option was excluded because of the need for the few specially configured C-130s which could fly so far to prepare for Operation Mikado.

But this option presented a considerable headache: the range of the helicopter and the need for Invincible, the aircraft carrier from where the chopper would take off, to be far away from the range of Argentinian aircraft once daylight came, dictated that this would be a one-way mission.

With such large stakes at play (the possible sinking of an aircraft carrier), however, it was decided that it such was a risk worth taking. The Sea King helicopter and its aircrew would come from 846 Naval Air Squadron, the only Navy Squadron equipped and trained to conduct nighttime special forces insertions.

Although they had only been issued with a few pairs of primitive night vision goggles (NVGs) after the sailing of the Task Force, through hard work and determination, the pilots had managed to master the art.

Since 1 May, they had inserted and resupplied numerous SAS and SBS patrols in the Falklands in preparations for the Task Force landings. Back in Hereford, it was decided that the two recce patrols be merged into one eight-man recce/fighting patrol.

This change would eventually have grave consequences for the outcome of the operation. Instead of a quick in-and-out reconnaissance of the airfield, which would have been easier with four commandos—and what the men preferred—the patrol was forced to sacrifice its secrecy, agility, and endurance—they had to substitute extra ammo and explosives for precious rations, only starting with four days’ provisions—for the slim possibility that they would be able to destroy the targets without the assault force.

The reason for combining the two patrols was a political one: the SAS high command—more specifically Brigadier de la Billière, the SAS director—feared that the Cabinet wouldn’t approve Operation Mikado, which would stretch the already strained bounds of legality to breaking point, and thus wanted the men of the reconnaissance mission suitably equipped to destroy the targets if necessary.

Once they had completed the mission, the troopers would escape and evade to neighboring Chile, while the aircrew would land in the neutral country before destroying the helicopter and making their way to the British consulate.

In secret, Pinochet’s Chile was friendly to the British cause, yet for diplomatic reasons, she remained outwardly a neutral nation.

From the beginning, Operation Plum Duff was plagued by poor planning and inconsistencies. Directly contradicting the special forces mentality, the men of 6 Troop B Squadron, who would perform the mission, weren’t included in the planning session; they were just briefed.

Moreover, the only available maps of the area were two Second World War land survey charts—one of them was ‘liberated’ from Cambridge University’s library and the other looked like it had been torn from a school Atlas—each in worst condition than the other.

Even a reconnaissance mission needs some prior information in order to be successful, yet Plum Duff was denied this. The obvious limitations and poor planning notwithstanding, the operation was given the green light.

On 15 May, the eight-man SAS team flew to Ascension Island. The following day they embarked with their equipment on a C-130 and parachuted into the cold, stormy waters of the South Atlantic before being picked up and ferried to Invincible.

During their drop, however, their uniforms and gear had been soaked because of their inadequate wet suits and poorly taped containers—the SBS that did have the adequate dry suits and waterproof containers hadn’t been consulted because of the cross-service feud.

Once aboard the aircraft carrier, the men desperately tried to dry their clothes and gear for that night’s operation. Fortunately for them, heavy fog postponed the mission for the following night.

On the early hours of 18 May, a specially configured Sea King, carrying eight heavy-laden troopers and three crew members, launched into the cold night. For the first 300 miles, the chopper flew at the comfortable height of 200 feet. Suddenly, and approximately 50 miles before landfall, a bright, eerie light flushed in the pilots’ NVGs.

Unbeknownst to them, an oil rig was situated there. Yet no one had briefed them of its existence.

Not wanting to alert the Argentinians of their presence, the helicopter descended at 50 feet and flew a circuitous route to the north. It was during this unplanned detour, that an Argentinian destroyer patrolling a few miles to the south had, unknowingly to the British crew since the Sea King didn’t have an internal radar detection system, spotted them.

Even before reaching Argentina their mission had been compromised. Once over land, the chopper dropped at 20 feet. Visibility was poor. Thick, heavy fog dominated the dark sky. Fuel was running low; the detour hadn’t been generous to their precious fuel reserves.

The ponderous Sea King was forced to a slow hover, cautiously probing the grey darkness. Flying above the fog wasn’t an option since Rio Grande’s radar would have instantly pinged them. The helicopter had to land.

The situation was dire. No one knew with certainty where they were. With every passing second, the chopper’s deafening noise increased their chances of detection. A heated argument ensued between the lead pilot and the SAS Captain commanding the patrol.

The patrol leader believed they were surrounded and wanted to relocate to the emergency infiltration point. Conversely, the lead pilot argued, incorrectly, that they were only a few miles from their planned insertion point. Crucial minutes passed.

“This was a horrible situation,” the SAS Captain recalled years after the operation, “there was such a huge weight of expectation for the mission to be successful, to be balanced against walking out of the helicopter into what may well have been an already compromised situation and perhaps even into an enemy position. . . It really felt like the posthumous Victoria Cross versus living to fight another day” (Southby-Tailyour).

The Captain’s authority prevailed. They flew to the emergency infiltration point.

After a brief and hectic flight, it became evident that the alternative drop-off point was inaccessible due to the thick fog. The pilots, believing that the mission had been aborted, flew to Chile to proceed with the planned destruction of the helicopter. The SAS Captain thought otherwise.

He informed the pilots that he intended to press with the mission and ask to be dropped off at the nearest possible landing clearing. The first such point was inside Chile, and nearly 80 miles from the Rio Grande airbase. Nonetheless, the Captain was firm.

The noisy Sea King landed. The SAS troopers pushed their 80-pound Bergens out of the cabin and set up a 360-degree perimeter. With the chopper already a distant and noisy memory, the commandos began their arduous trek.

Tactical procedures restricted them to march only during the darkness, with the days spend in hiding. This and their scant four days’ rations made the success of the mission all but improbable.

In the SAS, however, such arguments don’t exist. The men pressed on.

Endless miles of mossy grass and peaty soil. That is the best way to describe the featureless Terra del Fuego, which the patrol had to traverse. Furthermore, this was the infamous austral winter of Argentina. The rays of the sun, if they shone at all, were feeble. Temperatures were continuously below freezing.

Progress was excruciatingly slow.

After many twisted ankles and strained muscles, the patrol stopped to prepare for dawn. During the daylight hours, the Captain took stock of their situation. With their current pace, it would take them two-and-a-half days just to reach the border with Argentina, with Rio Grande being still 30 miles away. Clearly, the four days’ rations weren’t enough. The billiard-like landscape didn’t offer any eatable alternatives—and even if it did, they hadn’t been briefed on any eatable plants, which stands as another example of poor planning.

It was during these hours that one of the men became ill. Although not life-threatening, his condition forced them into a dilemma: they could spit, leaving three men to nurture the sick Sergeant while the other four made a run for Rio Grande (minus the extra ammo and explosives).

But this option was quickly rejected because they only had two maps. Orders were urgently needed. The Captain used his satellite phone to contact Hereford. Quickly explaining their unsustainable situation, he wasn’t shocked to find out that he was to proceed with the mission—by now, it had dawned to them that they weren’t expected to survive.

Meanwhile, the crew of the helicopter had followed their orders and tried to sink the chopper in a lake. Yet the trusty Sea King refused to sink, prompting them to burn it.

For several days and nights, they evaded the Chilean forces who were searching for them. Eventually, they were found and flown to Santiago and the British embassy. Their capture, however, had caused an international stir. They were forced to explain their cover story—supposedly they had been lost while searching for Argentinian submarines—in a televised news conference.

The Argentines were now certain that a special forces patrol had been inserted and heightened their vigilance.

Back in the wilderness, on the night of 20 May, the patrol restarted its slow slog towards the border. The constant freezing sleet, combined with the ankle-twisting ground, made their progress desperately slow.

When they hid for the day, they figured that they were still 40 miles away of Rio Grande. And although the sick trooper’s condition was improving, their fast-fading rations warranted a decision. They again called Hereford with an urgent resupply request.

Hereford’s answer wasn’t what they expected: they were to tab to the emergency rendezvous point, where an SAS liaison attached to the British embassy in Chile would pick them up. Since such a contingency hadn’t been discussed prior to launching the mission—yet another proof of poor planning— the men were perplexed.

Also, there was a significant issue with this order: the patrol was to meet with the liaison on the following night, 22 May, on a small bridge near the coastal road. But, due to the inadequacy of the maps, the patrol leader wasn’t exactly sure of their position.

With only twenty-four hours to reach the pick-up point, the men of 6 Troop tabbed into where they thought was the correct spot. By now, almost all their rations were gone and their radio irreversibly broken. Night came, the liaison did not.

They stalked the bridge for three days and nights. Finally, on the pre-dawn hours of 26 May, a starving SAS Captain went with another man to hitch a ride to the nearest town. Putting on civilian jackets and leaving behind their webbing and guns, except their 9mm Browning pistols, they quickly found a Chilean trucker willing to take them.

The truck dropped them at the small town of Porvenir, a few miles east of the city of Punta Arenas. Unshaven, smelly, and tired they blended rather easily with the rough lot that inhabits this far corner of the world. With the persuading powers of the dollar, they managed to find a dwelling and desperately needed food. Refreshed, they dialed the British consul in Punta Arenas.

The horrified bureaucrat on the other end of the line had, apparently, not been informed of their mission. He recommended that they surrender themselves to the Chilean authorities before abruptly hanging up.

More food and clothes would be required. Scouring the village for both, they unexpectedly stumbled upon their SAS liaison. After discreetly making contact, they informed him of the perilous condition of their comrades. That night, 27 May, six dirty, starving men emerged from their hideout near the bridges, and were driven away to the village.

Once cleaned and fed, they heard with amazement their liaison stating that the operation was still a go!

They should be prepared to cross the border with Argentina on a moment’s notice. The following day, however, their orders changed once again and they were ordered to fly to Santiago, the capital of Chile. There, they stayed in a safe house until their repatriation on 8 June.

Operation Plum Duff might have been a failure, with the SAS having no eyes on Rio Grande airbase, yet Hereford decided that Operation Mikado would proceed. The SAS were going to storm an airfield.