Taoiseach Micheál Martin left stranded in Brussels after Air Corps plane broke down

The incident in February embarrassed the Department of Defence, which was told it had twice in quick succession been unable to support the Taoiseach for vital EU and international engagements.

In emails, senior officials at the Taoiseach’s department said the latest breakdown marked a “further deterioration” in the service being provided for flying ministers around the globe.

Mr Martin had wanted to use the government jet to fly him and his delegation to Brussels on February 24 for an emergency meeting of EU leaders about the war in Ukraine. He had also planned to travel directly to his constituency in Cork on the return leg.

With the Government’s ageing €8m Learjet already out of commission for repair, plans were made to use a CASA maritime patrol aircraft for the trip.

The outward leg passed without a hitch, but the CASA developed a technical problem and was unable to fulfil the return journey.

Instead, a third aircraft, a smaller PC-12, which because of its single engine is not considered ideal for use by the Taoiseach or the President, had to be dispatched.

Tensions rose between the Department of Defence and the Defence Forces over the last-minute snag with the Ministerial Air Transport Service (MATS), according to records.

One email from a department official to Air Corps operations said: “It is imperative that I am notified as duty officer of any issues with aircraft related to MATS missions.

“I received no notification of the Taoiseach being stranded in Brussels from Air Corps this morning.”

The Department of the Taoiseach was also fuming about what had happened, with the Learjet having been unavailable for the Brussels trip and an earlier one to Berlin.

An email from a senior official in the Europe Unit and International Unit said: “This morning the Taoiseach was delayed by a number of hours returning from Brussels as the CASA went out of service, stranding the Taoiseach outside of the country.

“This week marks a further deterioration in the Ministerial Air Transport Service, which was not able on either occasion to support strategically important EU and international engagements by the Taoiseach.”

The Air Corps was asked to prepare a report on what had happened, with a senior officer saying the Learjet was now 19 and it was becoming difficult to get spare parts and technical assistance.

They also said the technical strength of No 1 Operations Wing maintenance squadron was at less than half of what was required. “However, they continue to do their utmost to resolve technical issues as and when they arise. Ministerial Air Transport Service is provided by a single aircraft and as such represents a single point of failure,” the report said.

The CASA that was drafted in for use was even older, at 28, with a high number of flying hours, and is due to be replaced. “While it is regrettable that the sole MATS aircraft was not available, the Air Corps used all remaining resources available to ensure that the principal passenger was facilitated by the most expeditious means possible,” the report said.

A Department of Defence spokeswoman said: “The Air Corps Learjet was purchased new in 2004, has been in operation for 17 years and is now approaching its natural end of life.

“The Learjet’s reduced availability and reliability in the latter half of 2021 has continued into 2022 with the aircraft being unavailable for 35pc of the year to date.

“While back-up service is sometimes provided by the Air Corps in the form of CASA fisheries patrol aircraft when other operational demands permit, these aircraft have also faced ongoing serviceability challenges.”