Leaving his teaching position at King's County Academy, Kentville Nova Scotia, Harold Thompson enlisted with the RCAF in October of 1940. The Oxford Nova Scotia native would have been surprised if anyone had told him that in less then two years he would be meeting King George in person.
From the time of his enlistment and through his training not much has been found. The early record keeping at 419 squadron was of little help in giving the exact date that he arrived at 419. The best that can be surmised is that he arrived with P/O Jost's crew sometime near the end of March or the very beginning of April. Even P/O Jost is not mentioned as coming to the squadron.
(The ORB records did not mention crew arrivals until much later in the war)

Since Jost is recorded to have first taken 2nd. pilot training on April 5th 1942 we can assume his crew arrived with him in the time line I have already mentioned.
P/O Jost's original crew were:
Navigator P/O Harold Thompson
Wireless Op. Sgt. Johnston
A/G F/S Fredrick W. Cassidy
R/G Sgt. Gerald C. Hart

Beginning Operations

P/O Thompson's first operational sortie was not until May 17th, the crew's next operation on May 30th was one which would become known as the 1,000 Bomber Raid. The idea of Bomber Command's Air Marshall Harris, under his " Thousand Plan."
Thompson and the rest of the crew were to be part of 419 squadron's contribution to this huge undertaking. The squadron was to ready 15 aircraft, all Wellingtons for the raid on Cologne. Wave after wave of bombers of all types available converged on Cologne in this massive show of the RAF's ability.
A second 1,000 bomber raid took place on the following night and P/O Jost, Thompson and the rest of the crew also took part in this second massive raid. The target for that June 1st. night was Essen.

P/O Harold Thompson Meets King George

After the June 1st sortie Thompson and crew were part of seven other operations for the month of June. A busy time for the relatively new 419 squadron, and for P/O Thompson. On the morning of June 25th., Thompson and the rest of the crew touched down at 0403 hours. P/O Jost his captain and he were to be on Parade in front of the King and Queen in a manner of hours after getting out of their Wellington
The King had asked to personally meet the men who had been on the 1,000 Bomber Raids, and both Jost and Thompson were requested to attend the ceremony in the hanger. Photos were taken and comments were most likely made, but only the photos have survived.
(The King's Visit)

Continuing On

Two days after meeting the King, it was business as usual. The beginning of July saw a change in the crew's Wireless Operator. July 8th is the last Battle Order with Sgt. Johnson listed as the wireless operator. P/O John Freestone would join them for one operation then Sgt. Hall became the Wireless Operator for four sorties. On the July 28th operation, P/O Freestone returned as W/O and would remain with Thompson and the others

September 2/3 1942

For most of the month of August the squadron was in stand down as the men and aircraft were moved to the new base at Middleton St. George. Thompson and the crew were one of the few crews called on to participate in an operational mission during this month. From that sortie on August 8th until their next operation with the squadron commander at the controls on September 1/2 the crew as with most of the other crews were involved in exercises and training flights.
The new squadron commander W/C Archibald Walsh had arrived at the 419 on August 5th, 1942 to replace W/C John Fulton who had been lost while on operations. W/C Walsh had already completed 27 operations before coming to the squadron. On September 1st he flew on an operation to Saarbrucken with a borrowed 419 crew. On the next night, September 1/2 he borrowed the crew of P/O Jost including Navigator P/O Thompson.

Wellington X3711 took off from Topcliffe a few minutes before eleven p.m., the Wellington was attacked by night fighter 9./NJG 4 sometime around 0210 on it's return to base. The aircraft came down six miles Northwest of Dinant at Warnant, Belgium.
This was P/O Thompson's 20th operation.
The crew are all buried at Warnant-Lez-Dinat Communal Cemetery at Warnant Namu Belgium.