In November 1921 delegates from the British Empire, the United States, the empire of Japan, France and Italy met in Washington DC to discuss the prevention of an arms race by limiting wRship construction. Prior to this in August the design for the new G3 battlecruiser had been approved by the Admirility and orders place with Swan Hunter at Walsend, William Beardmore at Govan, Fairfields at Govan and john brown Clydebank. Arthur Lee, First Lord of the Admirality ordered the construction to commence as a matter of urgency, but as part of the Treaty they were to be disposed of. but a reprieve was found, two were to be converted to aircraft carriers along similar lines as two American vessels. HMS Invincible was launched by Queen Mary on Saturday 10th October 1925 in Walsend. Her sister HMS Illusterious slips into the river Clyde at Govan on Monday 15th February 1926 after being named by Edward the Prine of Wales. On Monday 15th November 1926 HMS invincible set sale down the Solent, captained by Andrew Cunningham, his first big ship! with Commander william Dickson as 'air boss'. The air group consisted of 12 Fairley Flycatcher fighters, 24 Avro bison scout aircraft and 12 Blackburn Dart light bombers. NB several leading RNAS personnel opted to keep their commission with the navy as opposed to RAF in OLT.