The impact of the devastation caused in the USA on 11th September 2001 rippled across the Atlantic and Air Traffic Control Officer, Aidan McEnroe and his colleagues in the IAA Control Centre at Shannon quickly felt the impact.

This team is responsible for managing the safe passage of over 1,000 aircraft that fly to and from the USA into Irish airspace as they head for their destinations in Ireland, UK, Europe and Asia. These flights usually arrive in Irish Airspace from 3am and their return flights start from 11 am. Aidan recalls that fateful day as an Air Traffic Control Officer on duty on 11 th September 2001.

We always came back early from lunch to try and fit a quick game of snooker or to use the Internet. Lunch normally meant most of the team heading down to Shannon airport to dine in the airport terminal restaurant.

The previous few hours at work were forgettable, but the remainder of the day is etched forever in my memory. As we walked into the rest room/canteen, colleagues were engrossed with live tv coverage and tried to fill us in; “ Did you see this? a plane has hit The World Trade Centre, not sure what type”

As we gathered around the tv, the second plane hit. We were united in gasps and no doubt the gut wrenching feeling in our stomachs. Within minutes a junior member of staff came running into the kitchen. “The coordinator wants every Air Traffic Controller over to Ops room immediately”

The dilemma for the air traffic team was that by 2pm hundreds of aircraft were in Irish airspace, hundreds more over the Atlantic and it was uncertain what effect what they had just witnessed on tv would have.

When we opened the ops door, it was obvious we needed everybody, all the sectors were manned. I was only working for the IAA for 4 years and had never seen all the radar positions manned before. Instructions were quite clear, 3 people per sector, the third person to assist the planning controller.

As all the chairs were filled, I stood beside an already 2-person team covering SOTA sector, a rectangle piece of airspace, which includes the airspace over the Atlantic Ocean. All sectors consisted of a radar screen and a stripboard. So, one controller has a radar screen in front of them, the planner has a pc screen and the strip board as procedural backup.

I informed the planning controller that I was there to help. The controller had less than a years ‘experience, but she did something that I had the utmost respect for her, She turned to me and said: “I’m out of my comfort zone, can you sit in”.

To this day, as an On-The-Job training instruction, I always tell my students this story. It is vital as an Air Traffic Controller to honest with yourself and know when you reach overload, to be aware of that feeling and seek help from your colleagues.

So, I was now the planner sitting beside a very experienced controller, Jim, a controller that I always admired, a controller that nothing phased him, he had done this for years. I was reassured.

At that time, we didn’t know this was a hijack scenario. We had completed training at the end of 1999 for the possibility of system failures due to the Y2K bug. Was this what was happening now? Were aircraft navigation systems failing and somehow flying into buildings?

Pretty soon, pilots were getting information, via company messages, about what was happening in New York. They were calling us asking if we had any information. We had none. I could hear in their voices that there was real concern. Were they thinking that their planes may start descending or turning without their control?

News comes from the top desk that a third plane has gone down in the US, minutes later the word comes down: “It looks likes multiple hijacks and US airspace is closed”

Did the coordinator just say: “The US is closed??” We were in the middle of a busy westbound traffic flow, our sector was full of aircraft all heading one way, in the direction of the ocean and mostly for the US. Jim turned to me and in his wisdom, he said: “Remember this moment Aidan, this day will go down in history”. He fixed his chair in a position that leaned into the radar screen, I had never seen him so far forward.

If he was my student, I’d be telling him to relax and lean back a bit, but not that day. I also adjusted my seat to the same angle. Jim did a general broadcast on the frequency: “All stations on frequency, be advised the US is closed to all traffic, standby for further instructions”

Obviously, pilots were very busy themselves trying to get their own information from other sources and getting directions from their companies. One question came through from a pilot that started a chain reaction: “Is Canada still open?”

The response: “Yes Canada is still open”

Within minutes, the frequency became blocked with aircraft wanting reroutes to “Canada”, I don’t remember any airport being mentioned, just that most of the aircraft now wanted to land in “Canada”. I was sure, like them, we could sort out those minor details of a destination later.

Phone calls to our colleagues in other air traffic centres, like Shanwick, who control the ocean, were difficult, as every sector from Shannon was trying to contact them. It was a case of fastest finger first, when the light on the phone went out you pressed the button.

Shanwick advised that: “Anybody that wanted to go to Canada had to route 51n and north to enter the ocean. And Shannon, we have aircraft on the ocean who are less than halfway and they are turning around and returning to the departure aerodrome, more details to follow.”

Aircraft were re-routed to 51n and north as their new oceanic clearance came in. Some aircraft wanted to route there in anticipation of receiving a clearance.

The chain reaction had started, all the aircraft in the sector . A few minutes previous they were routing pretty much westbound. Now they were all turning right to aim for 51N, like a flock of starlings that had been spooked by a predator, all the leader line vectors were all now diagonal .

Then word came down: “ Canadian airspace is closed”

Another general broadcast was issued and another chain reaction of all aircraft now turning left to head south west, this time the destination requested was the Caribbean.

That didn’t last too long, there wasn’t any time to get any clearances for the Caribbean. when the word came through …….“Ocean is closed”

Not something I ever heard before, not something we had trained for, but that day everybody in aviation was experiencing something that they had never experienced before.

London and Brest control centres were told to send us no more aircraft unless they were landing in Ireland. Within minutes the first calls started coming in giving details of returning aircraft off the ocean, storage bins were being searched for the strips, on a normal day, once the strip slides down the chute to the bin, we don’t see it again, but not today.

We quickly reminded ourselves of the “turnback procedure” for an aircraft experiencing an emergency on the ocean: ‘Offset by half a degree and come in 500ft below your previously assigned oceanic route.”

The first ‘unknown callsign’ came on frequency, it was an early call, thankfully. It was a returning aircraft coming back off the ocean coming via the same point and same level that it had exited Irish airspace maybe 15 minutes previously. That’s like turning around on the M1 and driving back up the motorway you just came down. This wasn’t a day for giving out to the pilot.

The instruction was immediately given: “Change your level by 500ft and offset by half a degree as published”, We couldn’t see him on radar, but we were glad of the early call and the aircraft retuned safely.

Next instruction was to the conflicting westbound aircraft routing to the same point and same level as the returning aircraft to orbit left and hold. Once the message that the Ocean was closed calls started filtering through, many aircraft that could return to their departure airport elected to do so.

Because such a scenario was never envisaged, our system struggled with getting information to London and Brest control centres as they were also dealing with their own turnback’s. So, the frequency was too busy to get confirmed times for coordination points so a lot of guess work was used.

The turnback’s continued, not all using correct procedures, but at this stage we had nothing heading out against them, so one less worry. Soon every turnback was now declaring a fuel emergency and emergency ‘PAN PAN’ acknowledgements were being heard in the whole OPS room.

Not many returning aircraft could make it back to their point of origin. So, diversions to Shannon and our other airports were occurring. I remember overhearing that Shannon airport was running out of room on the ground for the aircraft.

Our shift went on way past its normal hours that day. Nobody complained. All aircraft were able to land safely having come back from a ‘Closed Ocean’.

As we walked out drained from the day, the station manager on duty told me there’s something on the canteen table for everyone.

Cans of beer had been bought for us to take home, I don’t drink beer but I liked the thought, I knew I needed something from the top shelf after that day. TV was still on as I walked out, I couldn’t look at it, I didn’t need to, I had heard all the emotions in the pilots’ voices, I knew it was bad.

I checked my phone as I walked out, I had numerous texts and missed calls and one voice mail. I dialled into my voicemail, there was a message from my uncle who was a priest, who got me interested in ATC almost 10 years previously.

A brief message that he was thinking of me and my colleagues as he could only imagine what we were dealing with.

With the lump in my throat, I thought, yep, we are all in this together, everyone that day, everywhere.

Image courtesy of Epiphan