RAF built decoy airfields to divert Luftwaffe bombs

By 1940, RAF fighter airfields were exactly the kind of target no amount of camouflage could conceal from a bomber crew flying directly overhead in daylight: a working airfield needs a long, flat, clear runway, visible aircraft, and constant vehicle movement, all features that stand out from the air regardless of paint schemes or netting. Conventional camouflage could soften an airfield's outline but could not make an active, functioning base invisible to a reconnaissance photograph or a bomb-aimer looking straight down.

Colonel John Turner, head of the Air Ministry's Works & Buildings department, recognized that hiding the real airfield was the wrong problem to solve. If a bomber crew could always find the genuine target once they were looking for it, the actual point of leverage was making sure they looked in the wrong place a few miles away instead.

Turner's team, working out of Shepperton Film Studios and drawing on the film industry's own set-building expertise, built K sites: full daytime decoy airfields sited several miles from a real base, complete with grassed runways, defensive positions, and roughly ten dummy aircraft per site built from canvas and wood by contractor Greens Engineering. Ground crews repositioned the dummy aircraft regularly to simulate the day-to-day movement a genuine, active airfield would show to German reconnaissance photography, so the fake base kept looking lived-in rather than static.

Built convincing fake airfields nearby, complete with repositioned dummy aircraft, so bombers chose to attack the wrong target instead of the real one.

Decoy airfields looked active, so bombers targeted them.

Real airfields stayed visible but were no longer the primary target.

Decoys absorbed bombs, reducing damage to real bases.

When an asset can't be hidden, make a decoy that's more attractive to attack.

Over 200 decoy airfield sites were built across Britain, and the daytime K sites specifically absorbed 47 recorded bombing attacks, diverting an estimated 117 tonnes of bombs away from the real airfields they were built to protect, according to Kent Archaeological Society's review of the wartime record. The complementary night-time Q sites, using lighting effects rather than physical dummy aircraft, proved even more effective, drawing 521 attacks and roughly 900 tonnes of bombs by the war's end.