As far as i know the RCAF in Germany had sqaudrons on qra ops with 2 a/c each. The 'Q' aircraft could be launched with an armed US nuclear weapon ( B57 bomb 5-20 kilotons; B28 bomb 70-350 kt; B43 bomb 1 Mt)within 15 minutes of receiving the 'go' order. This arrangement was called the NATO Quick Reaction Alert Force.
Missions were targeted at troop concentrations, airfields, bridges, assembly and choke points and other tactical targets in order to slow the massive tank formations of the Red Army as they poured into the Fulda Gap and on towards the Rhine River.
Mission profile depending on used device