European Studies to Investigate the Feasibility of Using 1000 ft Vertical Separation Minima above FL 290 Part I

Abstract

Primarily in response to airline pressures for fuel economies, ICAO, the International Civil Aviation Organization, established a study programme early in the 1980s to determine the feasibility of halving the vertical separation minimum (VSM) used above FL 290 to 1000 ft. This paper is the first of a 3-part article describing a European contribution to this programme. After outlining the aims and organization of the experimental work, it describes the choice of methodology available to measure height-keeping errors and gives an indication of the measurement accuracy achieved. Details of the data collections, the risk calculations performed and the factors found to affect height-keeping accuracy are given in Parts II and III. Overall, the work has shown that whereas it would be technically feasible to introduce a 1000-ft VSM in the North Atlantic region, other measures would be necessary before it could be used in continental airspace. Today, in certain areas, the need for a reduced VSM has become even more pressing in order to achieve the gains in airspace capacity necessary to handle rapidly growing volumes of air traffic.