No 70mph speed limit helps. Seriously If Heathrow actually opens a new runway it's Gatwick, that will suffer immediately. The BA beach fleet will run home to mamma asap Cathay Pacific straight into its preferred airport.Then you have easyjet, who no doubt wish to expand and start flights from Heathrow depending on how the landing fee issues progress. I can't see any legacy carrier operating long term from Gatwick if the Heathrow runway materialised Emirates, would leave asap as it's simply slot sitting and waiting for more LHR openings. BA never really wanted to succeed with Manchester be it using the wrong equipment, timings etc which is a great shame as BA could have been as successful as other airlines that have come in since the retreat of BA to festung LHR.