H3
Many years ago, the decision was made to close H3 to all traffic when Heathrow was operating on easterlies. The 'unofficial' reason at the time was that a Concorde departing from 09R got in 'close proximity' to a helicopter on H3 due to the need to turn right a very low altitude, and low initial r.o.c. when the afterburners were cancelled.
As Concorde has been out of service for many years, why is H3 still closed when Heathrow is on easterlies?