Two military helicopters will be flying over the Channel Islands and landing at Port Soif on Friday and Saturday this week.
The Merlin aircraft will be visiting Guernsey, Jersey, and Sark as part of an Emergency Planning exercise.
As well as a public viewing organised for Friday afternoon at Port Soif, the choppers will be visible in the sky above Sark and Guernsey at times over the two days.
People in Guernsey will be able to see the helicopter pilots carrying out their exercises along the west and south west coasts on Saturday.
A spokesperson for the States confirmed that the exercises from a Guernsey point of view will focus on testing emergency landing grounds across the Bailiwick.
The Royal Navy will also be doing some tests of its own.
The helicopters will arrive in Guernsey airspace on Friday.
They will be landing on the Port Soif sports field at 11:00 before taking off from there at 16:00.
The choppers will be available for public viewing between those two flights, from 14:00 until 15:50.
The helicopters will again land at Port Soif on Saturday morning but no official public viewing arrangements have been made.
The craft will land on the Port Soif field at 10:30 on Saturday before taking off from there at 12:30.
The pilots will then be conducting exercises over L’Eree and the south-west of the island on Saturday until 14:30.
The States’ spokesperson has asked anyone with livestock or pets in those areas to be aware that the exercises will cause some downdraft and noise.