It is understood the trust became aware of the CAA's interest at the same time.
When Barrow's departure was announced on Friday, Bolton said it was time for somebody else to take the trust into a new era.
Barrow would take annual leave before formally departing on December 31.
He has been chief executive since 2013 and the trust said he came from an extensive background in aviation as a pilot of both helicopters and fixed-wing aircraft.
Comment has been sought from Barrow, who had more than 20 pilots on his staff.
Newman was based in the Netherlands for five years, and before that was general manager of the transport division of Mainfreight in New Zealand.
His career at Mainfreight spanned more than 30 years and he played an important role in creating the very strong "family" culture that the company has developed throughout its global operations.
'"The board believes that Mark's extensive background with a highly successful New Zealand-based global company will be of enormous benefit to the trust," Bolton said.
During the next 12 months, the trust would move into a new base at Ardmore, bed in a merger with the Northland Emergency Services Trust and introduce more technologically sophisticated AugustaWestland AW169s into service.
"These changes are happening at a time when our helicopters are at their busiest, with summer bringing hundreds of thousands of people outdoors, participating in recreational activities that put extra pressure on our services.