 On 22 April 1942, the construction of two prototypes (serials "LZ548" and "LZ551") was authorised by the Ministry while Specification E.6/41 was produced and issued to cover the work.Accordingly, the company proceeded with the detailed design work phase of the DH.100 in early 1942.Internally designated as the DH.100 and originally named the "Spider Crab", the aircraft was entirely a de Havilland project, being principally worked upon at the company's facility at Hatfield, Hertfordshire.