During development of the earlier Hawker Typhoon, the design team, under the leadership of Sydney Camm, had already planned out a series of design improvements; these improvements cumulated in the Hawker P. 1012, otherwise known as the Typhoon II or Thin-Wing Typhoon. Although the Typhoon was generally considered to be a good design, Camm and his design team were disappointed with the performance of its wing, which had proved to be too thick in its cross section, and thus created airflow problems which inhibited flight performance, especially at higher altitudes and speeds where it was affected by compressibility. The Typhoon’s wing, which used a NACA 4 digit series wing section, had a maximum thickness-to-chord ratio of 19. 5 per cent (root) to 12 per cent (tip), in comparison to the Supermarine Spitfire’s 13. 2 per cent tapering to 6 per cent at the tip, the thinner design being deliberately chosen to reduce drag. In addition, there had been other issues experienced with the Typhoon, such as engine unreliability, insufficient structural integrity, and the inability to perform high altitude interception duties.