On May 13, 1982, the Pebble Island airfield was under observation by an 8-man team from the 22nd Special Air Service Regiment (SAS) who had been covertly inserted. They verified the Argentine presence and marked a landing zone for an SAS strike force. The SAS would be supported by naval gunfire from the destroyer HMS Glamorgan (D19). Coordinating the fire support would be the Royal Marine specialists of 148 Commando Forward Observation Battery.
In the darkness of May 14-15, 1982, the SAS troopers and the Commando gunners - 45 men in all - boarded two Sea King helicopters aboard the aircraft carrier HMS Hermes (R12) and headed towards shore.
The British raiders landed about three and a half miles away from the airstrip. Each man was packing their personal weapons plus a total of 100 81mm mortar rounds, antitank rockets, and the explosive charges that would be placed among the Argentine planes.
On their approach, they spotted an enemy sentry but weren't spotted and reached the airfield undetected. The SAS immediately began placing their demolition charges among the planes along the airfield.
As the British made their escape, they detonated the charges that had been placed around the planes. At that moment Glamorgan began her bombardment and the SAS poured mortar and missile fire at the airfield and the Argentine defenders.
Eleven enemy planes went up in flames, and the airfield's fuel storage and ammo dump were also destroyed. The Argentine defenders, thinking they were under an attack that would seize the airfield, completed their own destruction by setting off their own prepared demolitions!
Two of the British soldiers were wounded, but they all made it back to their exfiltration point and boarded the helicopters to return to Hermes before daybreak.
The Pebble Island raid was a "classic SAS operation". "[I]ts success was evidence of what a well-handled British force could achieve against far larger numbers of the Argentinians."
When news of the successful raid reached the main British landing force en route to the Falklands, morale soared. Their upcoming landing had one air attack threat lifted before they even got ashore.
This post drew upon Battle for the Falklands by Max Hastings and Simon Jenkins (pp. 186-187, quote source) and the Wikipedia article "Raid on Pebble Island".