Question: What did Brooklands produce that Forrestburn Hillclimb did not?

Context paragraphs:
Mike Pilbeam: Mike Pilbeam (born 1937) is a British motorsport designer and engineer known for his work with BRM, Lotus, Surtees and his own company, Pilbeam Racing Designs.  An early design was the experimental four wheel drive Formula One BRM P67 of 1964.  s of 2014 , Pilbeam's company continued to produce hillclimb cars and sports prototype chassis for endurance racing.

Forrestburn Hillclimb: Forrestburn Speed Hill Climb is a 1030 m hillclimb track near Kirk o' Shotts in North Lanarkshire, central Scotland.  The track opened in 1993, and was the first purpose-built hillclimb track in the United Kingdom to be completed since Brooklands in the 1930s.  Forrestburn Hillclimb is operated by Monklands Sporting Car Club, and all speed hillclimbs at Forrestburn are rounds of the Scottish Hillclimb Championship.  The site was designed by Willie Miller Urban Design as part of a projected Scottish motor racing circuit which was never taken forward.

Brooklands: Brooklands was a 2.75 mi motor racing circuit and aerodrome built near Weybridge in Surrey, England, United Kingdom.  It opened in 1907 and was the world's first purpose-built motor racing circuit as well as one of Britain's first airfields, which also became Britain's largest aircraft manufacturing centre by 1918, producing military aircraft such as the Wellington and civil airliners like the VC-10.

Supporting paragraphs: Forrestburn Hillclimb Brooklands
Answer: military aircraft