The Ruff method with matched scale and reference velocity was used to determine appropriate 1/2 scale test conditions to simulate a full-size icing encounter for an NACA 23012 wing section protected with a pneumatic boot de-icing system. Intercycle ice accretions were recorded on a 36-in-chord model used to represent 1/2 scale and compared with a hybrid reference model (full-size leading-edge and truncated aft section) representing a 72-in-chord full-size airfoil. The intercycle ice thickness and extent of icing for the scale tests generally compared well with those from the reference model. However, the scale tests did not reproduce the location and number of feather rows seen in the reference tests aft of the main ice shape. Many of the differences observed were believed to result from not scaling the pneumatic boot design along with the model size for these tests.