Complex sentence: All 44 Gannet AEW.3s were built at the Fairey factory at Hayes and the prototype and first two production aircraft were roaded to RAF Northolt for there first flight, the rest of the aircraft first flew at White Waltham Airfield.
Split into simpler sentences: All 44 Gannet AEW.3s were built at the Fairey factory at Hayes; the prototype and first two production aircraft were then transported by road to RAF Northolt for their first flight. The remainder of the aircraft first flew at White Waltham Airfield.