1990 British Army Gazelle shootdown On 11 February 1990 , an active service unit of the Provisional IRA East Tyrone Brigade shot down a British Army Gazelle helicopter ( serial number ZB687 ) along the border between Northern Ireland and the Republic of Ireland . It took place between Augher in County Tyrone and Derrygorry in County Monaghan . The helicopter was hit several times by heavy machine - gun fire and crash - landed on an open field , injuring three members of its crew of four . Background . Since early December 1989 , the British Army had been on alert in and around County Tyrone after a credible threat was made by a suspected member of the IRA about an imminent attack . On 13 December , a major assault took place when an IRA team raided a permanent vehicle checkpoint manned by members of the King ' s Own Scottish Borderers ( KOSB ) regiment near Derryard , County Fermanagh , just a few yards from the border with the Republic . Two soldiers were killed in an attack that involved the use of machine guns , rocket - propelled grenades and even a flamethrower . While British officials focused on members of the IRA from County Monaghan , in the Republic , supported by others from Clogher , County Tyrone , author Ed Moloney asserts that the culprit was a flying column made up of IRA volunteers from different brigades , commanded by Michael " Pete " Ryan from the East Tyrone Brigade . The execution of hit - and - run raids by the IRA was " professional " and " calculating " according to British military sources . Shootdown incident . On 11 January 1990 , a patrol of the King ' s Own Scottish Borderers was sent to investigate a suspicious column of vehicles close to the border with the support of an unarmed Gazelle helicopter from the 656 Squadron , Army Air Corps . The motorcade was actually a diversionary manoeuvre set up by the East Tyrone Brigade to lure the troops into an ambush . As usual during the KOSB tour in Northern Ireland , the soldiers would be backed up by a helicopter . The main mission of the helicopters was to airlift patrols to different locations during a single day . Another key role was to scan the terrain for potential enemy ambushes and to block the IRA getaway by landing reinforcements on their escape route . It was never determined if the Provisionals had previously planned the shooting of the Gazelle or if the helicopter became a target of opportunity . At 16 : 30 , a local witness heard 50 to 60 shots fired , then she saw the helicopter skimming over an open field just north of the border , near Derrygorry , in the Republic . The Gazelle , serial number ZB687 , was hit by a number of rounds and lost oil pressure . The crew was forced to crash - land the machine , which broke - up on impact . The RUC and British Army sealed - off the scene as an investigation was mounted . The official report confirmed that the Gazelle had been on a reconnaissance flight . Three crew members were wounded in the crash , one of them a sergeant major from the KOSB , who suffered spinal injuries . None of the injured was hit by gunfire . Another crewmember survived unscathed . The incident was covered by an ITN news report , which shows the helicopter wreckage being examined by Army technicians . The remains were kept under armed guard for further forensic analysis for several days before being removed from the field . The Provisional IRA claimed in a statement that they had fired 300 rounds at the aircraft from two heavy machine - guns and three automatic rifles . Some sources have speculated whether the machine - guns were either Soviet - designed DShK s , part of the Libyan shipments to the IRA in the 1980s , or American M - 60s . The Gazelle was eventually written - off . It was the first helicopter brought down in Northern Ireland by hostile fire since June 1988 , when a Lynx was brought down in South Armagh . Aftermath . The Gazelle shootdown raised fears that the Provisional IRA could have in mind another high - profile action before the end of the KOSB tour . After this and other attacks on security forces along the border in 1990 , especially against permanent vehicle checkpoints , the troops were issued with . 50 Browning machine gun s and M203 grenade launcher s . By 1992 , the use of long - range weapons by the Provisionals , like mortars and heavy machine - guns , had forced the British Army to build its main checkpoints along the border one to five miles within Northern Ireland to avoid assaults launched from inside the Republic . From 1990 until the first Provisional IRA ceasefire in 1994 , there were indeed a number of IRA actions involving heavy weapons in the border areas of Tyrone and Fermanagh , not far from the site where the Gazelle crashed , at least four of them involving British Army helicopters . On 19 July 1991 , the crew of a Wessex successfully dodged a surface - to - air missile at Kinawley , County Fermanagh . On 15 March 1992 , a Provisional IRA unit fired more than 1 , 000 rounds at two helicopters from across the border near Roslea , County Fermanagh . In 1993 , two helicopters were fired at in different circumstances , one of them on 8 January at Kinawley after a mortar attack on a British Army outpost , and the other on 12 December in Fivemiletown , after an ambush where two RUC officers from Clogher were killed .