Eyewitness: My main thought was that I hope I don't mess up

Flight Lieutenant Mike Rutland was still wearing his flying suit and his hands were still blackened with grime yesterday afternoon as he told his story. Little more than an hour earlier he had returned from a mission over southern Iraq – a mission that in its own way made history for both the RAF and for the pilot, 27.

Two hundred miles into southern Iraq, the Harrier pilot and his squadron leader had been diverted from their original, classified target. They were told by their flight controllers hundreds of miles away in Saudi Arabia that something had been spotted on the desert floor far beneath them.

"What had been spotted was a [mobile] surface-to-air missile launcher," the 4th Squadron pilot, speaking at the Al-Jabar air base, said. "I headed back with the squadron leader on my tail ... It was hard to see. It was moving very fast, swerving and then slowing up."

Flt Lt Rutland, from Norwich, had been informed of his original target two days ago – giving him plenty of time to think about what was to come, not least last night when he came on duty at midnight and was told that before he went to sleep he needed to put on his chemical suit in case of attack. It was Flt Lt Rutland's first combat mission, which can only have added to his tension.

High above the Iraqi desert as he and his squadron leader approached the mobile missile launcher, Flt Lt Rutland received a further surprise: he, and not his commanding officer, would be required to fire on the target. Flt Lt Rutland's Harrier was equipped with a Maverick missile – an American air-to-surface tactical missile that he said the RAF had not used before. But before he could fire it, he had to manoeuvre his aircraft into position. Flt Lt Rutland used his hands to help demonstrate the moves he undertook that put the Harrier in the correct position to fire. It took him between 30 and 40 seconds from the moment he was informed that he would be firing. "I was very nervous. My main thought was that I hope I don't mess up. You also think there must be some anti- aircraft fire coming up at you."

At this point – with the adrenalin flowing through his body – that Flt Lt Rutland said he spotted movement below. It was the operator of the missile launcher getting out of the cab of the vehicle and running across the desert, desperate to escape the Harrier.

With the Harrier in position, he fired the missile. Even from the height he was at he could see the weapon had struck. "There was a big whoosh," he said.

Group Captain Mike Harwood, 44, the base commander at Al-Jabar, said many British pilots had been fired at as they launched the strikes.

"There is a lot going on down there that they don't see," he said. "They see puffs of black and white smoke like you get in an old Gregory Peck film, but it's a lot more dangerous. Our job is to know what stuff they could have, stalk it. If it's something unpleasant, it has to go."