Similar as the two current LW threads: the best, but still plausible ways for the products of Hawker company (fighters, predominantly)to be top-notch. After the 1st flight of the Hurricane is accomplished - lets say from January 1936. Ending by the time people were trying to make a Mach 2 fighter. Includes naval aircraft.
Obviously, two big wars will be happening between 1936 and 1955 for the new Hawker products to take place, plus the Greek civil war and India-Pakistan war, as well as Israel vs. Arabs in 1948.