Sure it can be done. But the payload would be non-cost-effective.<p>Won't happen in practice.<p><i>can be started up and run at low speed</i> = "lack of thrust"<p><i>Also, liquid hydrogen takes up around four times the space as the same volume of kerosine</i> = no space for passengers.<p>(There is a practical limit to the physical size of aircraft in today's world. To go larger, we'd need to scrap the existing airtports and rebuild with new larger <i>expensive</i> ones.)