In this work we present experimental characterization results of a non- expensive massive ultrasonic transducer array to generate helical wavefronts in air. The multitransducer is composed by 390 elements operating at a nominal frequency of 40 kHz, precisely located on a helical surface substrate. The same excitation signal is applied to all elements. Due to the "spatial" delay applied to each element, the device is able to generate a helical wavefront of topological charge m =+1. A maximum sound pressure level of 137 dB was measured, on a transverse plane located 1.8 m far from the device, when a 15 Vpp excitation voltage was applied. This work also includes a detailed description of the excitation electronics, the electroacoustic characterization of the array elements (phase, directivity and frequency response) and the inter-element cross-talk quantification. Furthermore, a discussion of the potential of use of this multitransducer device is presented.