Aer Lingus has reported two separate emergency landings in the last two days.
This morning, Flight EI 592, declared an emergency onboard after a passenger became unwell.
There were 124 people on the flight from Dublin to Madrid which diverted to Bordeaux in France.
Yesterday, a flight enroute from Cork to London Heathrow had to be directed back to Cork after smoke was discovered on board.
That plane landed safely shortly before 1.30pm and all 149 passengers and crew were uninjured.
"Cork Airport can confirm that Aer Lingus flight, EI712, from Cork to London Heathrow returned back to the airport shortly after takeoff at 12.46 and landed safely at 13.23," Cork airport said in a statement.
"A full activation of the airport’s emergency plan was deployed with Cork City and Cork County Fire Services as well as HSE Ambulances turning out in support of the Cork Airport Fire and Police Service. All passengers have returned safely to the terminal."
One passenger aboard the flight was UCC Professor Barry O'Sullivan.
He told the Evening Echo the incident was dramatic but Aer Lingus crew dealt with the situation very well despite the aircraft not feeling "quite right" once it turned around.
He added passengers remained calm until the plane landed and emergency crew were waiting on the runway.
“There was a bit of panic when it came back as there were lots of emergency services around and so on,” he said.
“The flight had been delayed by about 45 minutes and we were about a quarter of an hour to 20 minutes into the flight and the captain announced that there was a technical fault so we needed to return.
“I travel a lot and the plane certainly didn't feel quite right on the way back. It was a little rougher than normal but there was nobody panicking, which is good," he added.
Professor O'Sullivan said the presence of emergency services on the runway spooked some passengers but they were oblivious to the problem in flight.
“It landed in the corner at the end of the runway and the emergency services at the airport were there to meet it. They opened up the emergency slides but I don't think they ended up using them. It was quite dramatic but they dealt with it very well," he said.
“It didn't become apparent that there was anything wrong. Often planes will turn back because there is something wrong, a little fault or something, but I don't think people really appreciated what was going on until they got on the ground and saw the fully suited and booted fire crew and that kind of scared people.
“There was nothing visibly wrong with the plane when we came out.
“[The pilot] made an announcement at the very beginning and once we landed he opened the doors and said 'leave bags, everybody evacuate immediately'. At that point, people wanted to get out quick.
“[The plane] was close to full, there could have been maybe 150 people on it. It was pretty loaded," he added.
A full technical investigation is now underway. Cork Airport remains open.