No. 5 Group Commander Ralph Cochrane provided the avenue for Cheshire's escape. Cochrane's elite unit, 617 Squadron, was in difficulty. Guy Gibson had been withdrawn from flying and taken on a publicity tour. He was succeeded by Wing Commander George Holden. Soon thereafter the squadron attempted the disastrous raid against the Dortmund Ems Canal, which resulted in the loss of five of the eight Lancasters sent, including that of the new squadron commander, Holden. Temporary command of the squadron had been passed to H. B. "Mick" Martin, one of the squadron's flight commanders. Of the original nineteen pilots that had flown the mission against the Möhne and Edersee Dams in Operation Chastise, only five remained alive. In September Cochrane asked Cheshire if he would be willing to take the job. Returning to squadron commander would require Cheshire giving up his rank of group captain and taking the step down to wing commander. Cheshire agreed without hesitation. Cochrane instructed Cheshire that first off he needed to complete a three-week conversion course on Lancasters at RAF Warboys.