In these full scale aerodynamic test program local aerodynamic quantities (forces, inflow velocities, inflow angles) are measured at several radial positions along the blade.The aerodynamic experiments at ECN were performed in two different phases:The non-rotating phase (1993-1994): In this phase the blade was mounted vertically on a non-rotating facility in the free stream. This test aimed at acquiring data at free stream conditions without rotational effects. Furthermore the instrumentation could be tested relatively easy in order to prepare for the next phase.The rotating phase (1995-1997). In this phase the blade was mounted on the HAT-25 experimental wind turbine and data were acquired under rotation. Furthermore some non-rotating measurements have been repeated. In this report the measurements from the rotating phase are reported only.The HAT-25 wind turbine is located at ECN near Petten in the Netherlands. The prevailing wind direction is from South-West, at which most of the measurements are taken. In this direction, the terrain upstream of the turbine is obscured by dunes over around 600 m. As a result, the turbulence intensities at the site may depend strongly on the conditions. Generally, the values of the turbulence intensities are between 5% and 20%.Time series measurements are supplied, in which the angle of attack ranges from negative values to deep stall values. Also measurements at yaw misalignment and at stand still have been supplied. Also sectional profile coefficients under rotating and 2D conditions are stored. The data file formats and the conventions have been harmonized (across all IEA Task 18: Enhanced Field Rotor Aerodynamics experiments) in order to make the full database easy accessible.

IEA Task 18 Acknowledgement: The support of the IEA R&D Wind Executive Committee which made it possible to cooperate in the Annexes XIV and XVIII is highly appreciated. The measurement programme on the experimental facility of the Netherlands Energy Research Foundation was made possible by financial support from the Dutch Ministry of Economic Affairs (Energy R&D Targeted Funding 1991-1995). In addition support has been obtained by the Dutch Organisation for the Energy and Environment, NOVEM, within the EGIB project (NOVEM project number 224.720.9640) and through NOVEM project number 224.750.9858 The contribution from Risø to the IEA Annex XIV project has been funded by the Danish Ministry of Energy under contract: ENS 1364/94-0001 which is gratefully acknowledged. The U. S. Department of Energy is credited for its funding of the Unsteady Aerodynamics test program through the National Renewable Energy Laboratory under contract number DE-AC36-98-GO10337. The measurement programme from Imperial College/Rutherford Appleton Laboratories was funded by the Department of Trade and Industry, Energy Technology Support Unit and Engineering and Physical Sciences Research Council. The measurement programme from Mie University has been supported by the Japanese Ministry of Education. Furthermore the European experimental programmes were funded through several JOULE projects. These JOULE projects are partly funded by the EU and partly by the participating organisations and/or their national agencies.