  Envisioned use cases of unmanned aerial vehicles (UAVs) impose new service
requirements in terms of data rate, latency, and sensing accuracy, to name a
few. If such requirements are satisfactorily met, it can create novel
applications and enable highly reliable and harmonized integration of UAVs in
the 6G network ecosystem. Towards this, terahertz (THz) bands are perceived as
a prospective technological enabler for various improved functionalities such
as ultra-high throughput and enhanced sensing capabilities. This paper focuses
on THzempowered UAVs with the following capabilities: communication, sensing,
localization, imaging, and control. We review the potential opportunities and
use cases of THz-empowered UAVs, corresponding novel design challenges, and
resulting trade-offs. Furthermore, we overview recent advances in UAV
deployments regulations, THz standardization, and health aspects related to THz
bands. Finally, we take UAV to UAV (U2U) communication as a case-study to
provide numerical insights into the impact of various system design parameters
and environment factors.
