It doesn’t take much to ground a whole airline - How the smallest data issues can cause the biggest problems.
A little thing can threaten a large business. When that business is an airline there are a lot of little things to manage. Things like values in a reference data table and ensuring those values are the same across paper charts and on-board instruments. It goes without saying that when you fly planes data quality errors can take on more importance.
In June 2011 a Tiger Airways flight into Melbourne dropped below the mandated safe minimum flying altitude for its approach to the airport. A month later another Tiger flight approaching Avalon Airport outside Melbourne (just a few minutes from my house) also dropped below the minimum altitude.
The Australian Civil Aviation Safety Authority (ACASA) had warned Tiger previously about safety problems and these two incidents were the final straw. Shortly after, the ACASA suspended Tiger Airways Australia’s operations saying that, “permitting the airline to continue to fly poses a serious and imminent risk to air safety.”
Tiger Airways remained fully grounded for five weeks, losing, an estimated, $1.5million a day in that time. On top of that, hundreds of staff in limbo were sacked by the CEO. It was over a year before all the restrictions imposed on the airline were lifted.
So how did all this happen?
A report on the first low-altitude incident showed there was a discrepancy between the data in an on-board navigation computer and the paper charts for the approach to the airport.
The flight crew did not notice that the documented arrival procedure had a lowest descent altitude of 2,500ft, while the data from the flight management guidance and envelope system’s navigational database had a lowest descent altitude of 2,000 ft.
The aircraft was approaching 2,000ft, when air traffic control advised the flight crew that they should be at 2,500ft and instructed them to climb.
Now 2000ft seems like a safe flying altitude; I haven’t been out with the tape measure but I’m pretty sure the power poles and two-storey buildings around Melbourne airport are shorter than 2000 feet. The second incident took place over the water of a bay so the only thing at risk from a low flying altitude is an extremely tall fisherman or an unlucky pelican.
But what these incidents demonstrate is a low level of governance maturity of the airline. The flight data is among the most important data that Tiger uses – it is of the greatest value to the organisation since it can threaten the safety of a flight or ground the airline. The data was uploaded from a third party source so Tiger did not think they had a responsibility to monitor its quality or check its accuracy during flight approaches.
As well as causing more than a few headaches, this incident highlights several key questions about data quality:
How did the inaccurate data get in there?
Why wasn’t it discovered in previous flights or by other airlines?
Do all pilots double check the navigation computer data against paper charts on ever flight arrival?
To ensure your important data assets are managed accurately and effectively click here to find out more about our Certus Data Quality Framework.