Network providers around the world have deployed 4G LTE technology in most of the major cities, providing the consumers with 4G services. However, a lot of remote areas still suffer from coverage holes and lack high speed connectivity that is crucial in emerging traffic hotspots eg emergency situations or mobile crowds. This paper discusses the use of small unmanned aerial vehicles that act as wireless flying relays, in order to offer 4G services on demand and assist the network performance. The presented analysis shows that for line of sight scenarios, an aerial vehicle with antenna gain no more than~ 18dB can support 10Mbps, for a user as far as 100Km. It is also demonstrated how the directional elevation antenna pattern of a typical 4G base station affects the link performance when the unmanned aerial vehicle flies close to the base station.