Laser Doppler measurements provide information on the flow field created by twin impinging jets in tandem through a crossflow. The present experiments were carried out for a Reynolds number based on the jet exit conditions of Rej=4.3x104, an impingement height of 20.1 jet diameters and mean crossflow velocities of 0.8 m/s < U0 < 1.6 m/s, corresponding to velocity ratios, VR= Vj/U0, from 22.5 to 43.8, and an interject spacing of S=6D. The results show a large penetration of the first (upstream) jet that is deflected by the crossflow and impinges on the ground, giving rise to a ground vortex due to the collision of the radial wall and the crossflow that wraps around the impinging point like a scarf. The rear jet (located downstream) is completely deflected by the crossflow, and no wall jet is localized upstream of the rear jet. The experimental results confirm the initial hypothesis that the alignment of the jets with the crossflow would create a special flow pattern. To complete the experimental work, the investigation continued for velocity beyond the limits of the experimental rig through computational simulations. The numerical results show that for the smallest velocity ratios the jets initially do not mix, but remain together in two layers. Three different types of flow regimes were identified, but for a V/STOL aircraft operating in ground vicinity the regime associated with strong impingement on the ground and a ground vortex is the most relevant. In both experimental and numerical cases the first jet deflection and the location of the ground vortex depend on the velocity ratio used. Finally, the numerical results allowed to extend the experimental results, and to prove that the deflection of the rear jet is due to the competing influences the wake, shear layer and downstream wall jet of the first jet and the crossflow.