Quick Reaction Alert is a high state of readiness, maintained by NATO air crews to ensure the safety of Alliance airspace 24 hours a day, 365 days a year. Fighter jets can be airborne within minutes to intercept and identify unknown aircraft operating within NATO airspace. Member countries provide the necessary aircraft and assets for the air policing of their own countries. For those countries that do not have this capability within or near NATO airspace, other NATO members will assist on a rotational basis.

NATO Allied Air Command (AIRCOM) provides 24/7 command and control from two Combined Air Operations Centres (CAOCs), one for the north and the other for the south of the Alliance. Portugal belongs to the CAOC in Torrejón, Spain. When needed, these Centres decide - according to the location of the incident - which interceptor will be scrambled.

The Portuguese Air Force shows us their QRA facilities at Monte Real Air Base and explains the state of readiness they have to maintain to be airborne within 15 minutes. On average, the Portuguese Air Force has 300 flight hours and carries out about 8-10 scrambles per year as part of the NATO CAOC in Torrejón.