looking back at some BAE's concepts for internal bays some pop up a, so I'll make a little thread, some of the most interesting one are from the pre-Tempest era (around 2015) and very similar to one of the rotating one here proposed
However to properly start off a little background would help, in fact in 2018 BAE Systems was testing their concept of flexible bay door. TIt uses the bay more like a simpler thub in the fuselage to allow for multiple connections and different installations 2/N
