Ensuring Efficient GSE Movements on Constrained Apron Areas

Passenger boarding equipment, fuel trucks, pushback tractors, buses, cargo loaders, and baggage loading systems are among the various examples of ground service equipment (GSE) used on an apron.

Whenever airports want to optimize aprons, or introduce new aircraft stands, planners must assess how GSE integrates into the proposed designs.

The key to successful stand design is to ensure GSE can maneuver to and from their operating positions without interrupting other processes in play at the time.

Apron Planning Challenges

Today, airport planners can utilize simulation software to conduct GSE vehicle movement studies to assess the operational impacts of their role in the aircraft turnaround process. These account for each vehicle’s physical and steering characteristics, expected speeds, and operating positions.

Airport GSE vehicle movement studies can highlight both feasible, and non-feasible, maneuvers. The data, combined with analysis and implementation by qualified operational teams, often leads planners to adjust their designs.

Setec International utilized AviPLAN from Transoft Solutions in two recent projects, the Terminal 2 extension at Nice International Airport in France, and the West Apron changes at Belfast International Airport in Northern Ireland.

Gianluca Speca, airport planner at Setec, said: “In both cases, we were working with two very constrained spaces in terms of stand requirements.”

Carlos Reis, airport planner at Setec, added: “We had to consider GSE movements for baggage cart trains, loaders, and buses due to the volume of circulation across the stand. And in Nice, we also had a [new] passenger boarding bridge to fit in.”

Gianluca noted numerous complexities in apron maneuvering. During regular turnaround procedures, GSE often conflicts with process or space requirements, further complicating their planning.

A baggage loader, for example, may have to take a particular path around an aircraft because of how another vehicle is positioned. And different vehicles’ speeds, and turning angles, can change depending on how they are driven on the day.

Gianluca said: “We can’t simply simulate the path of a fuel truck in isolation. We also have to consider the positioning of the passenger boarding bridge (PBB), or mobile stairs on a remote stand, as well as the tug, loaders, carts and dollies operating at the time. You have to simulate a range of movement scenarios, which can be a real challenge.”

The Results

In both the Nice and Belfast projects, Gianluca found that GSE vehicles would have to undertake a complex double turn maneuver on the apron, consisting of a left turn followed by a right turn, to go around an aircraft.

AviPLAN offers multiple data points to accurately simulate the turning characteristics and behavior of GSE, which enables the software to produce extremely detailed swept path studies for airports.

During the projects at Nice and Belfast airports, Setec planners utilized AviPLAN to develop a hypothesis identifying the most efficient maneuvering strategies for GSE vehicles navigating complex double turns.

AviPLAN simulations revealed that, during the left turn followed by a right turn, GSE operators would be required to restrict the vehicle’s wheel maximum steering angle to approximately 80%.

Gianluca pointed out: “We changed the maneuver based on the hypothesis. This kind of simulation would not have been possible without AviPLAN.”

A key advantage of the software, he emphasized, is that the hypotheses it produces are “directly translated into a visual simulation”.

He explained: “When you speak to a vehicle operator, you need to talk about something that is clearly visible. The percentage of steering applied by a fuel truck driver is theoretical. In practice, a driver cannot precisely determine whether they are using 75%, 80%, or 85% of the steering.”

Gianluca said the video presentations produced by AviPLAN are “very, very useful and necessary for this kind of study.” They enable all stakeholders to see the consequences of specific maneuvers, leading to the correct actions being adopted in real operations.

Another example of when AviPLAN’s capabilities are crucial in apron planning is when assessing connections between fuel trucks and aircraft, as inevitably different aircraft types have different fuel hose connection points.

Carlos said: “We found it useful that you can display the fuel port of each aircraft [type] in AviPLAN, and when all are shown at once, a cloud of all the fuel connection points is created.”

He explained: “For instance, you know the fuel truck has a connection point and the length of its fuel pipe. By combining AviPLAN features with CAD elements to generate 5m and 10m activity circles, you can immediately see whether your connection points fall within range of the truck’s connection point.”

By using AviPLAN, Setec was able to identify if any GSE vehicle would conflict with the aircraft, the refueling truck, and the fuel pipe – and modify the apron plan accordingly.

Turning Simulation in AviPLAN. Image provided by Setec International.

Apron operations require ‘right first time’ maneuvering, because in many situations, vehicles are not permitted to reverse during turnaround operations. Some vehicles, such as baggage carts and cargo dolly trains, cannot be reversed at all.

Transoft Technical Product Specialist Guillaume Desmedt said: “When you’re in a car, and you miss a parking bay, you can usually correct it. That is not easily possible on an apron; you have to respect safety measures.”

Vehicle movement studies need to account for the positioning of all required GSE, such as caterers, cargo loaders, and passenger boarding equipment. Airports also want flexibility in their aircraft stands, for example, handling a large Code E/Code F aircraft for one flight, before switching to two smaller Code C aircraft for the next.

Fundamental to AviPLAN’s functionality, Guillaume said, is its ability to allow airport planners to input all, or only the specific GSE relevant to local operational needs, directly from the software. This allows planners to undertake multiple studies into vehicle movements.

Guillaume noted AviPLAN uses an iterative process that often requires multiple vehicle movement studies, which can result in a lot of digital variants. But most of these planning variants remain in the digital environment, which results in less plans needing to be generated.

Setec’s Gianluca said: “You can easily modify or exchange AviPLAN models to verify if a previous study is still valid, and add any number of predefined models, removing the need to replicate the whole study over and over again.”

AviPLAN’s precision impressed Carlos, and he commented that the movement studies were directly ready to use. “The airport operator may need to conduct internal studies to confirm the proper functioning of the apron under its responsibility. However, the appropriate services, such as refueling, buses, and other GSE can already use these simulations to familiarize themselves with the plans and validate the feasibility of the maneuvers.”

Gianluca pointed out: “The fact that you can exchange [data] upstream, fix the hypothesis, and test with both airport and GSE operators, simplifies the downstream work. You end up with nearly ready-to-use turning studies, which can be directly implemented in the design.”

The detail in AviPLAN provides “a precise idea of the impacts of each turning simulation”, Carlos added, “which results in a very quick outcome of what you are planning.”

Gianluca concludes “Within Setec, we are planning to expand our use of AviPLAN and increase our expertise and users of the tool.”