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.
Guernsey gets behind community café after online appeal
Guernsey Waste warn of the fire hazard of disposable vapes
No rush to ban social media for the under-16s in Guernsey
Guernsey businesses encouraged to use the daily St Malo ferry for European imports
Guernsey's airline to drop its European holiday routes
A total ban on disposable vapes in Guernsey and Jersey is poised to take full effect
Guernsey's Air Display to remain an early evening event
Disgraced Guernsey politician and pastor jailed for 9 years
