There were no armed police officers at Glasgow Airport when the terminal building was attacked last Saturday, BBC Scotland has learned.
Armed police are deployed when the national threat level is high
Armed police were on duty at most other major British airports at the time.
The two men arrested at the airport were tackled by an unarmed officer, an off-duty policeman who was passing by and members of the public.
A force spokeswoman said armed officers were only deployed to the airport when the national threat level required it.
The government raised the threat level to "critical" for a short period after the attack.