*2.2.2. Superconductivity*

Superconductivity is considered as an enabling technology for electric drive application to transport aircraft [13, 38, 39]. Through the utilization of High-Temperature Superconducting (HTS) materials, the gravimetric specific power and the efficiency of the electrical component can be significantly improved. The most common application of HTS materials at this point in time is for electric motors and generators [38, 40, 41]. The application of HTS technology to the transmission cable is also considered [10, 11]. The necessity of developing fully superconducting network (including the fault management, protection and switching implications) was argued by Malkin and Pagonis [42]. The challenge of HTS application for transport aircraft lies essentially on the requirement to operate at cryogenic temperature and the resulting complex integration of the cooling system. Instead of using fossil fuels to operate the aircraft, the utilization of cryogenic fuel such as liquid hydrogen can result in strong synergies with the layout of HTS electrical system as the coolant is already available [10, 13, 39]. Handling safety related issues [43], the negative integration impacts of the cryogenic tank on aircraft design [44] and the infrastructural challenges to supply the liquid hydrogen to the operated airports all are issues that remain unresolved [45, 46].
