Every discussion about changing anything in aviation ends up at “the big S”. It’s all about safety, so the discussion is over. This is the stick used to beat down anything that would mean daa, AirNav Ireland or the IAA changing something. Used like this, it paints anyone who disagrees as anti-safety. Nobody says it out loud, but the implication is that listening to anyone else will put your flight to Lanzarote in danger.
So let’s talk about safety.
Turning the go-around into the departures
When a plane landing on the south runway (28L) has to abandon its landing, it flies the published missed approach. Here it is, the white dashed line, against the departures from the North Runway in green:
The go-around flies straight out to the west, turns right, and comes back east across the North Runway’s departure routes near Ratoath. You don’t need to be an expert in airspace management to see that turning missed approach aircraft into the face of departing traffic is not a way to make anything safer.
It doesn’t have to go that way. The rules require the two tracks to split by 30 degrees, but they don’t say which one turns. The IAA told the Oireachtas Joint Committee on Transport in November 2023 that, “In principle, the missed approach procedure for 28L could turn left”. Turn the go-around left, away from the departures, and the North Runway’s departures can fly straight out, as the planning permission assumed.
AirNav Ireland says alternative missed approaches for 28L “were briefly examined” at the start of the project and “dismissed … due to the airspace restrictions”. So the departures turn over Ratoath instead, and the go-around still turns back into them. The Win-Win Proposal sets out the alternative.
And the departures turn low
The departure routes from the North Runway make every aircraft turn 30 degrees right, to the north. The departure chart says “Turn at 650ft QNH”. That’s aviation speak for 650 feet above sea level. The runway is about 250 feet above sea level, so the turn starts about 400 feet off the ground. And turning is bad for climbing.
Many of the larger aircraft can’t make the turn where daa drew it. They are so heavy and climbing so hard that they haven’t reached 400 feet by the end of the runway. By the time they do, they are off course and need a bigger turn to get back on it, sometimes 40 degrees right, then 10 degrees left a mile later. The others make the 30 degree turn and, about a mile later, reach a waypoint that needs a second turn of about 56 degrees right.
Take one of the biggest aircraft using Dublin every day, an A330:
- going transatlantic
- full of passengers
- full of bags
- full of fuel
So, very heavy. It lumbers through 400 feet and we make it turn. It just gets its wings level, and 30 seconds later we make it turn again, twice as far. Losing an engine 400 feet off the ground, in a maximum-weight A330, in a 30 to 40 degree turn, is every pilot’s nightmare. You will not find a pilot who will describe this as safer than climbing straight ahead.
So the next time you hear “it’s a safety issue, so we don’t have a choice”, you’ll know it may not be what you’d call accurate. Story 1, How a safety rule became a turn aimed at Ratoath, tells how the turn came about. It put about 14,000 people under departures that were never meant to fly over them.