Possible Clues:

• The country's top people emerging from Heathrow?
• Squirearchy's got good record
• Estate owners acquired information on tax
• Squirearchy
• They have grounds for belonging to the upper classes
• Eg lairds arrived gradually, going from left to right
• Estate-owning aristocrats touched down on grand approach
• What parachutist should have done with a change of side for rich countryfolk
• Rich countrymen used parachute perhaps swapping sides near the end
• Toffs driving from the airport?