Planes narrowly avoided crash at Knock Airport

Planes narrowly avoided crash at Knock Airport


Lack of communication one of the main contributing factors says report

Ciara Galvin

TWO planes carrying out technical checks over Knock airport last year narrowly avoided a mid-air crash, a report into the incident has detailed.
Airport investigators into the incident, which happened on April 22, 2013 over Ireland West Airport Knock, said one of the planes was forced to make a ‘last ditch manoeuvre’ to avoid collision. The report outlined that this action was already too late and it was only ‘fortuitous’ that there was no serious accident.
The planes were carrying out technical checks at the same time, over the same runway when they came within just hundreds of metres of each other. Each of the flights were carrying two crew and a flight inspector.
The Air Accident Investigation Unit (AAIU) which published the report on Tuesday last, has criticised the lack of communication and co-ordination by engineering sections, the calibration companies and Ireland West Airport Knock for allowing the two maintenance flights to carry out aerial work over the same runway at the same time.
In a transcript of the communication between one of the air traffic controllers and one of the flight crew, the controller was recorded as saying: “It’s kinda very unusual for us to have both of ye here at the same day.”

Technical checks
Ireland West Airport had brought in a private UK company to carry out technical checks on its navigational aids on the day, while the Irish Aviation Authority (IAA) had ordered another private UK company to also complete similar checks on the same runway.
The report found that airport technical chiefs did not give prior notification to traffic control about the other maintenance flight directed by the IAA.
Though both planes had approval for the aerial work, there were no prior notifications, with air traffic controllers only being informed about one of the flights 20 minutes before it arrived.
In a statement issued to The Mayo News, the airport explained that prior to this occurrence ‘the IAA and Ireland West Knock had used the same company to calibrate their navigational aids. On this occasion Ireland West Knock had received notification from the company carrying out the flight checks on Ireland West Knock navigational aids of the impending flight check, but had not received notification prior to the morning of the flight check from the IAA engineering department.’

Yellow warning
The report detailed that the Diamond Twin Star aircraft came within 0.42 nautical miles - or 700 metres - of the Piper plane. Neither plane could see each other until the yellow warning was present on the Traffic Advisory System (TAS) on the Diamond Twin Star.
This system monitors the airspace around the aircraft and advises the flight crew where to look for the transponder equipped aircraft that may pose a risk.
The commander of the Diamond Twin Star then carried out a manoeuvre to avoid a crash, after the TAS showed that both planes were at ‘co-altitude’.
According to the report, the situation was made worse because of clouds, and there was no radar equipment at the airport at the time.
In relation to the lack of radar equipment the airport said Air Traffic Control at the airport operates in a ‘procedural environment’, meaning that the controllers separate aircraft procedurally without the use of radar.
“This is perfectly legal and all controllers at Ireland West Knock are appropriately licensed and rated by the Regulatory authority,” outlined the statement.
Contributing causes to the near miss were outlined in the report and included the lack of prior and ‘timely coordination’ between engineering sections, the calibration companies and air traffic control at the airport. The attempt by the airport to accommodate both aircraft and the non-availability of radar were all cited as contributory causes.

Recommendations
The report put forward just one recommendation specific to the airport relating to the review of procedures relating to calibration flights, ie, planning and scheduling.
Ireland West Airport Knock stated that this recommendation had already been identified in the airport’s internal investigation and this has already been put in place.
Other recommendations outlined the need for the Irish Aviation Authority to review their procedures, and for the UK companies to ensure that ‘adequate and timely briefing is provided to air traffic control prior to conducting calibration flights’.
It was also put forward that the European Aviation Safety Agency (EASA) should consider a requirement for all calibration aircraft in Europe to be fitted with traffic collision avoidance system.