Hi Karen,
The VS015 (1pm flight) is generally operated by the 747 with UC.
The VS027 (11am flight) uses the A333 most frequently, 51% of the flights have been operated by the new airbus (from 'Which Aircraft?' tool.)
The VS27 looks to run daily until 8th January when only the later 1pm flight operates.
Not sure on the exact workings of the schedule but the running a search for your preferred dates on the VS website will show UC availability of using the "Schedules" section in toolbox here on v-flyer.
Cal
