These airfields were intended for use by returning bombers suffering from low fuel and/or suspected damage to their pneumatic (wheel brake) and/or hydraulic (undercarriage) systems. All three airfields were equipped with one runway,  long and  wide. There was a further clear area of  at each end of the runway.
At each of the three airfields, the runway was divided into three  lanes. The northern and central lanes were allocated by flying control, while the southern lane was the emergency lane on which any aircraft could land without first making contact with the airfield. Over 1,400 bombers made an emergency landing at Carnaby by the end of the war.