Editing V bomber (section)

==Withdrawal of the Valiants==
In July 1964, a Valiant of No. 543 Squadron (WZ394) on a deployment to Rhodesia was found to have cracks in the rear wing spar and was ferried back to the UK for repairs. The following month, a Valiant from No. 232 Operational Conversion Unit (WP217) suffered a wing spar failure during a training exercise over Wales. The whole Valiant fleet was checked, and many were found to have significant cracks in the wing spars. Those that were considered to have little or no damage were cleared to fly, but with a temporary restriction to a maximum speed of {{convert|250|kn|kph}}, maximum load of {{convert|0.5|g0|abbr=on}}, and a maximum bank angle of 30 degrees. When Vickers commenced repairs, it was found that the damage was more severe than first thought, and the entire fleet was grounded on 9 December 1964, and withdrawn from service. At first it was thought that the switch to low-level flying was the cause, but cracks were also found in Valiants that were in service as tanker and strategic reconnaissance aircraft, and had not been flown at low level. Suspicion then fell on the aluminium alloy that had been used, DTD683. One Valiant (XD816) remained in service as a test aircraft, having been re-sparred.{{sfn|McLelland|2013|pp=101–103}}