To counter paratroops or the hostile landing threat, RAF airfields had secure Battle HQs on or near the airfield, with a commanding all-round-view. The defence of the airfield was co-ordinated from there. They contained a Commanding Officer’s room, a messengers and runners room, a telephone room, an observation room and a chemical toilet. Old Sarum had two. One has been demolished completely, the other was converted into a toilet block in the 1960s and still serves in this role today.

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There were four Light Anti-Aircraft batteries on Old Sarum and a U9P rocket projector battery Z10 in a field just to the south of the monument. 13th Royal Artillery Regiment,131 Battery crewed six nine-barrelled projectors there. Salisbury had Heavy Anti-Aircraft Batteries of four 3.7-inch mobile guns at Hurdcott with GL Mark IA radar manned by 300 Battery of the 98th Royal Artillery Regiment Odstock, and Netherhampton manned by 301 Battery of the 98th Royal Artillery Regiment, and at Netherhampton with GL Mark II radar.

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Gun crews had to identify friend from foe, and fire at planes dropping bombs, and planes or gliders dropping paratroopers or attempting (hostile) landing. Junker 52 planes were used by the Germans for hostile landings in Europe.

Salisbury Cathedral made finding Old Sarum airfield easy. There were decoy or dummy “Q” type airfields at South Newton and Clarendon Park, and “Starfish” decoys mimicking burning areas at Winterslow, Odstock and Clearbury Down, all lit up at night to confuse the enemy.