Another well-argued post as usual, Frank. But most of us are actually persuaded by the operational case for expanding LHR. The barrier is the price-tag, which although "unknown" as you say (in an absolute sense) is convincingly "known" to be pitched at an exorbitant level. That is the nature of the objection: value for money. And the likelihood that despite HAL contributing to the cost of supporting infrastructure, the public purse will still be lumbered with a bill amounting to multiple billions of pounds. Money which cannot then be allocated to investment-starved regional initiatives which offer better value to UKplc by an order of magnitude.