Following the closure of the Trafford Park Aerodrome ( Manchester ) in 1918 after only seven years of spasmodic use Alexandra Park Aerodrome was constructed and opened in May 1918 by the War Department for the assembly test flying and delivery of aeroplanes for the RAF built in the Manchester area by A. V. Roe Company ( Avro ) at Newton Heath and the National Aircraft Factory No. 2 ( NAF No. 2 ) at Heaton Chapel .