This one is Poecilobothrus nobilitatus or Semaphore Fly, one of the most studied flies mainly because of its' size and easily identifiable sexing.

By the way for those of you who are wondering where I've suddenly acquired this expertise from, I get a good photo and upload it onto UK Diptera Facebook and a 'proper expert' with tell me almost instantly what it is and from there I can google it to find out a few snippets of interest about it, even Dr Erica McAlister sometimes.