Current powered lift aircraft studies include those which propose to utilise high specific thrust engines vectored for vertical landing.In ground proximity the high pressure, high temperature, exhaust plumes create a hostile environment for the aircraft, ground crew and equipment, and the landing platform.The potential difficulties have re-awakened research interest in the fields of: Ground surface erosion. Near field/mid field noise. Upwash impingement on the aircraft. Ground sheet temperature and velocity. This paper describes the physical nature of these problems, discusses some of the perceived operational difficulties and makes suggestions for further work, under each of the above headings.Ground proximity also creates other problems; notably ingestion of hot gas into the engines inlets and jet re-circulation induced forces and moments on the aircraft, but these are outside the scope of this paper.