A Scots airline resumed normal services on routes between Glasgow and the Scottish islands from about 1300 BST.
Loganair's flights were suspended on Thursday in line with concerns for aircraft safety following a volcanic eruption on Iceland.
The airline has restarted flights to Barra, Benbecula and Islay.
Highlands and Islands Airports said all flights from its sites to airports in England were cancelled until at least Saturday morning.
It is also flying from Glasgow to the Isle of Man.
The destinations are in the west and deemed to be away from the plume of ash.