As far as i know no property searches in the UK have ever considered low flying routes- as the information is not available to the local councils whom the solicitors turn to for the information. Legally, information is required on the likes of rights of way, former industrial use, contamination, proximity to land fill etc- but no such requirement is made for aircraft transit routes (as opposed to being on an airport flightpath etc).
Council tax payers would moan at the cost of constantly updated digital aviation charts being purchased by their council for what they would consider a non essential service.