620 Squadron was formed from a nucleus of "C" Flight, 214 Squadron, on the 17th June 1943. Based at Chedburgh and equipped with Stirlings, it was initially used in a night-time bombing capacity and carried out its first sorties two days after its formation. The Squadron flew its last mission for Bomber Command on the 19th November 1943, and three days later its twenty aircraft moved to Leicester East for conversion to the Airborne Forces role. Over the following months, the aircrews were trained in the art of towing gliders, dropping parachutists and supply containers.

As of the 4th February 1944, 620 Squadron flew numerous sorties over France on behalf of the Special Operations Executive (SOE), dropping arms and supplies to the Resistance forces, frequently using Tarrant Rushton as a forward base. On the 18th March, the Squadron was moved to RAF Fairford, which it shared with 190 Squadron, and training continued apace. During the remainder of that month, its aircraft carried out six exercises with airborne troops, each involving between eight and sixteen aircraft.

Normandy

620 and 190 Squadrons were both heavily involved in the first night of the Normandy landings. Commencing their take-off at 23:30 on the 5th June 1944, the two Squadrons carried between then eight hundred and eighty-seven men of the 5th Parachute Brigade to DZ-N, near Ranville. Twenty-three of 620 Squadrons Stirlings were used on this first lift, of which three were shot down by moderate anti-aircraft fire, and a further four received damage. Upon their return to Fairford, however, it was discovered that no fewer than twenty-seven aircraft from both squadrons were in an unserviceable condition, but the ground crews worked feverishly throughout the night and by morning all but two had been repaired.

On the evening of the 6th June, eighteen aircraft from each squadron helped to transport the main glider element of the 6th Airborne Division to their landing zones. Between them, the Horsa gliders that they towed carried two hundred and fifty-four men, thirty-three Jeeps, twenty-nine trailers, eleven motorcycles, and eight 75mm Pack Howitzers of the 211th Battery, 53rd (Worcestershire Yeomanry) Airlanding Light Regiment, RA. All but one of 620 Squadrons Horsas managed to reach their intended zone, at a cost of one aircraft shot down and six damaged by small-arms fire. The aircraft that was brought down was piloted by Flight Lieutenant Thring, who made a successful crash-landing in a field and, with all his crew safe, was able to contact friendly forces and return to base.

This lift marked the end of 620 Squadron's involvement in the invasion, and thereafter until August it resumed its SOE and SAS resupply flights with several Airborne Forces training exercises in between.

Arnhem

On the 17th September 1944, 620 and 190 Squadrons played a key role in the opening phase of Operation Market Garden, with each of them providing six Stirlings to carry to the Arnhem area the pathfinders of the 21st Independent Parachute Company, whose job it was to mark all of the drop and landing zones for the First Lift, half an hour in advance of the main force. The deployment was a complete success and was achieved without loss to the aircraft. A further nineteen of the Squadron's aircraft were involved in the main lift, each towing a Horsa glider, however three of these were forced to cast-off prematurely. On the following day, twenty-two Stirlings towed Horsas to the same landing zones, all but one of which arrived successfully. This latter glider was brought in by the Squadron with the Third Lift on the following day, accompanied by a further seventeen aircraft which dropped supplies.

On Wednesday 20th September, seventeen Stirlings took part in the resupply flight, with 620 and 190 Squadrons delivering six hundred and ninety-six canisters and one hundred and sixteen panniers between them. The Squadron suffered its first losses on this day with two aircraft shot down. Two aircrew bailed out from the first aircraft but were captured upon landing, of the remainder two RASC despatchers and four aircrew died, one of the latter having successfully bailed out but was drowned in the Rhine. The second aircraft was brought down by flak, three aircrew and two despatchers were killed, but three men survived.

Eleven of 620 Squadron's aircraft took part in Thursday's resupply effort, and in spite of an extreme level of anti-aircraft fire coupled with interception by enemy fighters, the Fairford Squadrons managed to deliver two hundred and forty canisters and thirty-four supply panniers. Two aircraft were lost in the attempt, one of which without any loss of life, the other made a crash-landing near Renkum after being hit by flak, one crew member and two despatchers were killed, but five aircrew survived the impact.

Wing Commander Lee led ten of his Stirlings to Arnhem on Saturday 23rd September, however his aircraft was shot down but all aboard survived. 620 Squadron's final sorties were carried out on the following day, with just five aircraft carrying supplies to the beleaguered 1st Airborne Division, however the situation on the ground was now so confused that only one of these was able to locate the dropping point.

From the 17th to the 24th September, 620 Squadron had flown a total of one hundred and four sorties to the Arnhem area, at a cost of five aircraft lost, eight aircrew and seven RASC despatchers killed, and seven men taken prisoner. A further fifteen men had bailed out over Arnhem, but these were successfully evacuated to the Allied lines when the 1st Airborne Division withdrew across the Rhine.

The Rhine Crossing

620 Squadron were employed in a variety of tasks in the months that followed Arnhem. On the 28th September they participated in a supply drop to Allied troops in Eastern France, and following a move to Great Dunmow on the 17th October, they carried out a series of drops to resistance forces in Holland and Norway. During January and February 1945, they were also engaged in several tactical bombing raids, dropping 500lb bombs on significant targets behind the German lines.

On the 24th March 1945, 620 Squadron returned to the Airborne Forces role when thirty of its Stirlings were used to tow Horsas on the first and only lift of the 6th Airborne Division to Hamminkeln; all but two of the gliders reached their allotted zone.

When hostilities in Europe came to an end in May 1945, the Squadron flew elements of the 1st Airborne Division to Norway to oversee the German surrender. Shortly after, the Squadron replaced its ageing Stirling fleet with the more powerful Halifax bomber. In January 1946, 620 Squadron was moved to the Middle East where, in June, the Halifaxes were exchanged for Dakotas. On the 1st September of that year, the Squadron ceased to exist when it was renamed 113 Squadron.

Commanders of 620 Squadron