In September 1940, No 10 Elementary Flying Training School at RAF Weston-super-Mare established a Relief Landing Ground on at Broadfield Down by the hamlet of Lulsgate Bottom, southwest of the city and north of Redhill village. Being high, at , the site had a poor weather record during warm front conditions, when it was often covered in low cloud. However, when this occurred the alternative airfields at Filton and Cardiff were usually clear and operational; and as Lulsgate was clear when the low-lying airfields were obscured by radiation fog in calm weather, the landing ground provided a useful alternative. Few facilities were constructed although pillboxes, defensive anti-aircraft guns and later two Blister hangars were added. In late 1940, a Starfish site was set up south of the village of Downside and just west of the airfield. Its decoy fires attracted a large quantity of Luftwaffe high explosives and incendiaries on the nights of 16 March, 3 April and 4 April 1941 during the Bristol Blitz.