Despite appearances, he's not wearing a porcupine on his head. This is the new Helmet Mounted Symbology System (why we had to use a different acronym to everybody else to describe a Helmet Mounted Sight is beyond me!) that is now - finally - being introduced to the RAF Typhoon fleet. This allows the full engagement envelope of the ASRAAM to be utilized, and also incorporates HUD information and infra-red imagery. It is still only deployed with the trials unit.