ESDU 76028 gives correction formulae for fully-attached flow on a two-dimensional model spanning the tunnel at mid-height. The tunnel is rectangular-section@ has solid side walls and either closed@ longitudinally-slotted or perforated roof and floor. The corrections are of two types: lift-interference causing an upwash distribution along the tunnel and blockage. The consequential corrections are given for lift@ drag and pitching moment and for the stream quantities: static pressure@ density@ static temperature and hence Mach number@ Reynolds number and kinetic pressure. Their application is explained and care is taken to distinguish in the case of drag corrections between the two cases of either balance measurements or wake traverse.