Contrail forecasting techniques used within the UK Meteorological Office have changed little since the early 1940s and there has been no formal verification of the results. Recent research has shown that old forecasting techniques may not be wholly applicable to modern aircraft that now use more efficient engines. In order to compare the performance of both the old and new forecasting techniques a validation trial was carried out over a nine-month period in which RAF pilots reported when and where contrails did and did not occur. These observations were compared with the predicted contrail levels from both the old and newer forecasting techniques. The results indicate that both techniques give a similar performance and that neither significantly out-perform a simple persistence prediction.