IRISH Air Corps jets patrolled the airspace around Monasterevin, Co Kildare, during the famous siege there after the kidnapping of Dutch industrialist Tiede Herrema because the Government feared the IRA would launch a helicopter attack.
The 1975 kidnapping was the longest and most dramatic in Irish history, lasting 36 days, and included an 18-day siege at a council house in Monasterevin where kidnappers Eddie Gallagher and Marian Coyle held their victim captive surrounded by the security forces.
Dr Herrema had been kidnapped in the hope that three high-profile republican prisoners, including Dr Rose Dugdale who was linked romantically with Gallagher at the time, would be released.
But as the siege dragged on in the full glare of the world's media, the authorities believed there was a real threat the IRA would attempt to infiltrate the area -- or even use a helicopter in a raid.
The IRA had previously hijacked helicopters in a brazen breakout of republican prisoners from Mountjoy. They also used one in an attempted bombing of an RUC station
A new book on the Fouga Magister armed jet trainer, six of which served with the Air Corps for 24 years, said No 1 Fighter Squadron was tasked with maintaining the aerial cordon around Monasterevin until the siege was brought to an end.
Fouga Magister -- an Irish Perspective by Joe Maxwell and Radu Brinzan said the operation also involved Vampire jets.
Retired commandant Geoffrey O'Byrne White, who took part in the mission, told the authors: "What we were supposed to do in the event that a light aircraft or helicopter had tried to get near the siege house in Monasterevin, I'm still not quite sure.
"But as is often the case, our mere presence may have acted as a deterrent to anyone thinking of doing something like that."
The Fouga, the last jet trainer to serve with the Air Corps, ironically was also the first to launch an air attack on Irish troops.
It happened during the UN Congo operation when Irish troops were besieged in Jadotville in 1961, when a Fouga bombed and machinegunned them.
The Irish responded by firing every weapon they had including World War One-era Vickers machine-guns.
The Fouga was hit at least once, forcing it to attack from a higher altitude.
The plane, flown by a Belgian mercenary for the Katangan air force, also strafed a press conference given by Dr Conor Cruise O'Brien, the then personal representative in the Congo of UN Secretary General Dag Hammarskjold.