The Garda Air Support Unit was established in September 1997 with the delivery of a Pilatus Britten-Norman BN 2T-4S Defender 4000 fixed wing aircraft and a Eurocopter AS355N Eceuriel helicopter. The unit is based at Casement Aerodrome, Baldonnel on the outskirts of Dublin city although from time to time aircraft may be based at other locations within the State. Garda aircraft may be deployed to incidents in the following cases: Immediate threat to lifeIncidents of a criminal, terrorist or other nationally important natureImmediate threat of serious public disorderTasks leading to the prevention or detection of crimeEvidence gatheringIntelligence gatheringPhotographic tasksTraffic Management/Monitoring In 2001, the Garda Aircraft fleet got a second helicopter, a Eurocopter EC 135 T2. During 2007 the Eceuriel helicopter was replaced by a second EC135 T2+. Both EC135 helicopters are fitted with Turbomeca (T2) engines. These rotary wing aircraft are classified as light utility helicopters.Garda aircraft are maintained on the Irish military register. Irish Air Corps personnel pilot all aircraft and provide maintenance facilities on behalf of the Department of Justice, Equality & Law Reform.All aircraft in service with the unit are selected to meet stringent operational policing requirements. The aircraft are fitted with the latest police role equipment including state-of-the-art daylight and thermal image cameras mounted on gyro stabilised platforms, search lights, extensive communication suites and microwave downlink/uplink technology.