Unnecessary turbulence

For the past five years, at a major airport on the east coast, there is a permanent turbulence Notam due to building generated rotor near the touchdown point of the main runway. In short, the building is too close to the runway and of an inappropriate design. At the same airport, on the cross runway, instructors and their students are landing long to mitigate turbulence from an even more inappropriate building north of the touchdown area. It begs the question how did the second building attain approval given it was built four years after the building related turbulence Notam was issued for same airport?

If you allow residences to be built close to airports you will get an increase in noise complaints. If you allow inappropriate buildings to be constructed on airports you will end up with serious safety concerns. How much longer will this stupidity continue or will someone have to get hurt or worse first?

Serious, public analysis of the aerodynamic or operational effects of the building on the adjacent runway is not a current criterion. If the building is outside the CASA runway splays it is generally approved, all other criteria being met. Surprisingly, there are no ICAO aerodynamic standards for on-airport buildings although recent studies have been undertaken by Hong Kong and Schipol Airports.

The main issue is that with the privatisation of airports there is an increased potential for inappropriate buildings to be constructed as owners seek to maximise the return on their investments. The operational problem is that the airport surveyors based their design calculations on large cleared areas while allowing for a few buildings of moderate height disturbing the airflow. It was understood by the surveyors that it is particularly important aircraft on mid to late final be allowed to stabilise their approach. The turbulence problem is exacerbated with a moderate or light wing loading given that these aircraft have more potential to be destabilised by building generated rotor while relatively close the ground. The consequences will always be alarming and potentially very dangerous depending on the wind strength and direction, severity of the turbulence, height to recover and the experience of the flight crew.

The rapid expansion of on-airport buildings at major and regional airports is highlighting a safety issue that should have been foreseen. Aircraft on approach are at their most critical flight phase and should not be subject to excessive or unpredictable building generated rotor. Tall, perpendicular buildings with sharp edges are likely to cause the most severe turbulence. Such buildings should not be approved anywhere near a runway.

Careful building design and placement can mitigate many of the emerging problems and allow safe operations as well as giving airport owners the chance to realise their business goals. However rampant, unscientific on-airport building development will cause increasing problems for pilots and may lead to a completely preventable accident. A number of recent incidents are already the subject of official investigation and the findings are keenly anticipated by the regional aviation industry.

Economic imperatives are one thing but they should not influence a building approval process that may have a dangerous effect on operations. This issue will compound as airport development gathers pace. It must be understood by policy makers that airports are subject to the same laws of aerodynamics as aircraft. To ignore this connection will lead Australian airports and operators down a potentially dangerous path.

Pilots in command are relying on a coordinated safety system that will assist them to make a stable approach and a safe landing. Building generated turbulence must be taken seriously, investigated immediately and action taken. To do otherwise will be to place pilots and their passengers at unnecessary risk.

If the unthinkable happens and there is an accident caused by building generated rotor who will be responsible? Will it be the Minister? Will it be the airport operator? Will it be the building owner?