The Guernsey-based charity, which has been involved in numerous search-and-rescue operations in Jersey, said that despite the losses it was still able to respond to incidents.
But it declined to give further details about what had led to the walkout.
‘Any loss of crew is completely regrettable, whatever the circumstances, especially when so many hours have been freely given to saving lives,’ a CIAS spokesperson said. ‘However, there must be complete harmony for the crew to operate safely.
‘When that became lacking, and it also became clear that attempts to resolve issues were not going to be to everyone’s satisfaction, decisions had to be made in the best interests of the charity.
‘We are a voluntary organisation and no one is under any obligation to volunteer for Air Search,’ the spokesperson added.
The walkout comes during the charity’s 40th year of operation and following the delivery of its new aircraft last June, at a cost of £2 million.
It was built after the previous plane, the Lions Pride, crash-landed in a field in St Mary in 2013 during a search operation for two fishermen.
The charity spokesperson added: ‘Air Search is fully operational and able to offer a limited capability search-and-rescue service in compliance with the Covid-19 restrictions, as agreed with States of Guernsey Public Health and the director of civil aviation.
‘We do not believe publicly discussing Air Search matters is beneficial to anyone, so it is therefore out of respect that we will not be commenting further on crew matters.’
The charity has been involved in a number of high-profile operations, including the search for Adrian Lynch in 2016.
It also helped search for the plane carrying footballer Emiliano Sala and pilot David Ibbotson, after their aircraft crashed into the sea near Alderney in January last year.
