Why not load up your 400 at LHR, fly to AMS, do a touch and go and then onto long haul destination. Each pax only pays the £13 short haul / band A tax. The Dutch scrapped the tax ages ago to support their aviation industry. When every long haul flight starts to do this then the public / politicians are going to question WHY. It's the same reason why aviation fuel isn't tax. Operators will find a way around it.