[1.05b18] Turbojet Model oddities

[Pratapon51]

VTOL Turbojet Engines do not have Turbojets as a prerequisite. They only require Jet Engines. Either the technology is inaccurately named or the prereq is an oversight.

Heavy Aircraft (4e) and X-Heavy Aircraft (4e) can be built with Turbojet engines even if the Turbojet technology has not yet been researched. This is not the case for Heavy Aircraft (2e) and X-Heavy Aircraft (6e).

[Vic]

Both will be fixed in beta21.

Thanks for reporting these oversights