On Tuesday, Sunak used a helicopter for an engagement in Norwich, a trip of little more than 100 miles. In May, he flew to and from Southampton to visit a pharmacy for an NHS-related announcement, a 160-mile round trip where the train takes an hour and 15 minutes each way.
We have decently fast trains to a lot of places, and he is taking the helicopter for journeys that wouldn't be that long on the train. Plus you can actually do some work while riding the train, which is difficult in a car and pretty impossible in a helicopter.