Blizzards, sandstorms and freezing temperatures are just some of the extreme conditions airports have to contend with. Though not unavoidable, it is now easier to predict and mitigate weather phenomena. Vaisala’s Kenneth Hörhammer looks at how a new generation of automatic weather-observing systems can help airports maintain safety and efficiency in the face of rising passenger traffic and testing conditions.

Depending on their location, airports regularly have to account for extreme weather – from Siberian blizzards to the monsoons of the Pacific, and safety and efficiency are at the heart of concerns.

Freezing temperatures leave snow and ice on the runway, aircraft wings and engines, while tropical storms impede visibility, jeopardise take-off and landing, and can halt refuelling operations due to the risk of lightning. Recently, Eliat Airport, the second-busiest in Israel, was forced to close due to an intense sandstorm.

Passenger safety remains of paramount importance; any sign that an aircraft could be endangered by any weather phenomena will see it grounded. It’s a mantle that has left the US aviation industry counting the cost after the record-breaking freezing temperatures and heavy snow experienced in January affected more than 30 million passengers, with 49,000 flights cancelled and 300,000 delayed. Some statistics suggest that the cost to airlines could be as much as $150 million.

"The challenges of the air traffic industry have been evident for some time," says Kenneth Hörhammer, global business director for the airport division of Vaisala.

"There is a clear need to decrease operational costs for airlines and airport operators, and all while air traffic is increasing at the same time.

"But when you’re outdoors, you’re at the mercy of the weather; it has a significant impact on airport operations. Wherever an airport is located, basic weather parameters can be used to gauge wind speed and direction, temperature, humidity, air pressure, cloud height and visibility – all of which contributes to a safer situation."

Weather, beaten

The consequences of extreme weather are often unavoidable, but predicting it in good time can certainly help mitigate its impact. Safety, scheduling and costs are all jeopardised by adverse weather conditions, and with increasing traffic, the need for more accurate weather information is growing.

Automated weather-observing systems (AWOSs) are now mandatory internationally, with even stricter regulations imposed on airports operating in especially challenging environments.

"Civil aviation authorities and other airport stakeholders are turning to high-precision systems for automated weather observations, and fully unmanned AWOSs are now evaluated and deployed more frequently," says Hörhammer.

"The AWOS creates the foundation of operational airport systems. Though they’re fundamental to airport operations, the minimum regulatory requirements in many areas are not stringent enough to cope with extreme local weather, and more bespoke solutions are needed.

"Even if the minimum requirements are met, there may still be significant threats to safety, efficiency and, ultimately, costs. If the local weather, and its impact on a specific airport, has not received proper attention and adequate priority, then the risks for unexpected hazardous weather conditions will grow. This awareness and insight is an area that Vaisala is trying to address," Hörhammer adds.

A Finnish manufacturing company, Vaisala specialises in engineering products and services for environmental and industrial measurement. Its airport business unit exists to help operators with weather-related challenges, offering real-time and reliable observation information under all weather conditions. Its first aviation-specific weather-observation system was delivered in 1975, and it has since grown into an industry leader with more than 1,600 completed projects across 90 countries.

A widely adopted platform is its low-level windshear alert system, designed to detect hazardous conditions caused by rapid changes in wind speed and direction.

It provides users and, ultimately, pilots with a higher situational awareness of the windshear phenomena – allowing them to make safer operational decisions – and provides comprehensive data for timely decision-making in all regions where thunderstorms pose a threat.

The skill gap

But no matter how accurate an AWOS’s data is, its value is impeded by a lack of skilled personnel to maintain it.

"A global challenge at the moment is the inadequate training of users and the implementation of proper maintenance procedures," says Hörhammer. "In addition, it is not uncommon for aviation authorities to rely only on the minimum requirements set by the International Civil Aviation Organization (ICAO). They don’t appreciate the importance of observing local weather.

"For example, we’ve designed a fully integrated AWOS solution with wide-area lightning and windshear alerting systems. It consists of the Vaisala AviMet system, which has the capability to integrate wide-area lightning information created by a global detection network – the GLD360.

"This information enables operators to track the movement and direction of thunderstorms, helping them to identify approaching risks presented by cloud-to-ground lightning and potential low-level windshear events."

As passenger traffic increases, the pressure to avoid weather-related delays mounts. In colder climates, this entails the deployment of runway weather information systems and de-icing strategies. For tropical climates, Vaisala has a system that estimates the depth of water on runways, as well as lightning-detection technologies, ranging from single-point detectors to a global lightning data network.

However, as Hörhammer points out, the burgeoning need for automated weather systems does not always translate into the necessary investment.

"The demand for weather information is significantly greater when talking to users and operators at airports than the typically government-directed availability of funding. Therefore, a gap exists between users’ needs and the ability to fulfil them," he says. "As a result, demand fluctuates from year to year, based on investment priorities as well as the overall economic situation of each region."

Decreasing operational costs is a current priority across the aviation industry for airlines and airport operators. Installing AWOSs may incur short-term expenditure, and, as a result, there is a tendency to adopt the bare minimum in order to adhere to regulations, but a more comprehensive network could provide invaluable long-term gains in efficiency and safety. With air traffic increasing, the need for appropriate AWOSs far outweighs the need to reduce expenses.