Rust debris has begun falling from the structure, meaning passengers are using an alternative entrance to the terminal building.
The problem became apparent during the afternoon of 21 August.
Passengers on inbound Aurigny flights are instead having to use the entrance set up to keep social distancing during the pandemic.
The concrete legged control tower is several decades old and has a number of steel elements to it.
An engineering inspection will take place today, 22 August.
Work was due to be underway by now on the complete refurbishment of the airport, including lengthening the runway.
But it has been paused, after it came in £13M over budget.
More affordable alternatives are being considered.
Percival the Puffin released close to his Herm home
Guernsey FC Women to begin FA Cup campaign
Full deployment of Guernsey's search and rescue assets off Herm
End to fare subsidy for Sark residents needing a medical appointment
Jersey and Guernsey women's teams to make FA Cup debuts
Eventful summer Saturday in Guernsey
No decision on GST for Guernsey until the autumn
New gaming venue opening in Guernsey this summer
