One overflew my area heading about 110 degrees -Camberley/Sandhurst yesterday very distinctive noise compared to the C130 steady thrumming noise .
Seemed to vanish off FR 25 5 n=minutes later although it was over head me at FL270. They could come and play at LHR all day if the almost complete absence of LHR traffic is anything to go by which adds to the general air of stillness and boredom