Air impingement cooling in a cylindrical cavity has been experimentally investigated. The temperature histories of a number of locations underneath the cavity walls have been used to inversely calculate the heat transfer coefficients at the walls. The local heat transfer coefficient is found to depend strongly on position. The average heat transfer coefficients for the cavity end wall and side wall have been correlated with the air flow rates. Within the range of impingement distances investigated, they are only weakly dependent on the impingement distance.