Despite having undertaken assessments of several relatively small airfields in the past, WA became involved with airport archaeology in a much larger way during 1998. The British Airports Authority (BAA) was considering developments at some of its most important airports such as Heathrow, Stansted and Gatwick. Archaeological investigations would be needed at each airport on such a scale and with deadlines so critical that it was considered impossible for any single company to complete the work. As a result Framework Archaeology, a joint venture between Wessex Archaeology and Oxford Archaeology, was set up to take on the task.
The first Framework projects were at Heathrow Airport, where BAA proposed building a new terminal, Terminal 5. Aerial photographs and previous excavations had shown that the surrounding area and the airport itself were rich in archaeological remains.
Investigations within the airport at Perry Oaks Sludge Works and at Mayfield Farm, outside the southern perimeter, set the scene for work in future years.
Meanwhile, ongoing fieldwork (away from the noise of Heathrow Airport) continued, and several Iron Age sites were investigated. Excavation of a Late Iron Age enclosure at Lea Farm, Hurst, Berkshire, followed on from a WA evaluation that had been carried out eleven years earlier. At Watchfield, Oxfordshire, another evaluation found evidence of several Iron Age enclosures and a Romano-British cremation cemetery. Another Iron Age settlement was investigated at Battlesbury Bowl, near Warminster, not far from the Iron Age hillfort of Battlesbury Camp.