Figure1. Double deck bus into the wind tunnel The aerodynamic balance, built by the authors according Tusche [11], is based on strain gage type cells arranged as a double Wheatstone bridge acquiring simultaneously data of horizontal and vertical loads. The incoming data is processed by Vishay series 2310 signal conditioners and amplifiers. In order to visualize the complex flow around the model, a smoke machine was used. The smoke was ejected near the model by a tube of 3mm diameter. That machine was made at the LaCLyFA. In order to determine the yawing moment Cm of the model, it was let free to rotate around its cg and the balance was fixed to left front wheel. The experiments were conducted for the values of mean wind velocity and angles of attack described above. Figure 3 shows the lateral sides and frontal part of the bus with the location of the pressure taps. There were 64 pressure taps. Figure 3. Pressure taps distribution around the bus model (64 pressure taps)