 Complete the following phrase:  Born in Otago in New Zealand, MacKenzie joined the RAF in 1937 on a short service commission. After completing his flight training, he was posted to No. 41 Squadron where he flew Hawker Furys and then Supermarine Spitfires. He flew several patrols covering the beaches at Dunkirk during Operation Dynamo and then fought in the Battle of Britain, during which he destroyed several German aircraft. He was later sent to Singapore to join No. 488 Squadron, raised to strengthen the aerial defences of British Malaya. The squadron flew extensively during the 