On the density of rational points on elliptic fibrations

Let $V_1$ be the Fano threefold given as a hypersurface of degree 6 in $P(1,1,1,2,3)$ (over a number field $K$). Then there exists a finite extension $K^{\mathrm{\prime }}\mathrm{/}K$ such that the set of $K^{\mathrm{\prime }}$-rational points of $X$ is Zariski dense.