Taxiway Editing Limitations In Wed: An 8-Word Overview

The WorldEditor (WED) is a tool that allows users to create and edit custom airports and overlay scenery in the X-Plane flight simulator. WED enables users to create taxiways, taxi routes, and other elements of an airport. However, it is important to note that WED does not support the editing of base terrain meshes or 3D models of aircraft and other objects.

To create taxiways in WED, users can utilize the taxiway tool, which allows for the creation of taxiways and other pavement surfaces using Bezier polygons. It is important to ensure that the outline of the taxiway does not cross over itself to avoid issues. Users can also add markings, signs, and lighting to taxiways using the appropriate tools in WED.

When creating taxi routes, it is crucial to follow certain guidelines to ensure proper functionality. Taxi route segments should not cross each other unless connected by a common node, and the entire grid of taxi routes must be connected to allow for continuous movement. Additionally, every runway used in any flow must have a taxi route to facilitate aircraft movement to and from the runway.

While WED provides tools for creating and editing various aspects of airports, it is worth noting that the software has limitations. For example, WED does not support bezier curves in the taxi route tool, so users must use short segments to approximate curves.

Overall, WED offers a comprehensive set of tools for airport design and customization, but users should be mindful of the software's limitations and follow the guidelines provided to ensure successful taxiway and taxi route creation.

Taxi routes are a collection of line segments

• Taxi route segments cannot cross each other unless they are connected by a common node. WED will automatically prevent this by placing a node where two crossing taxi route segments overlap.
• The entire grid of taxi routes must be connected – there should be a continuous path from any one route to any other. This means you cannot build an airport with disjoint movement areas, even if it exists in real life.
• Every runway that is used in any flow needs to have a taxi route so aircraft can get to and from the runway.
• Segments are colour-coded when viewed in the ATC Taxi + Flow tab, providing an immediate sense of the properties assigned to each segment.

The most basic taxi route segment is for the taxiway on the pavement surrounding an airport. These are typically drawn over the line markings that guide aircraft around the airport. They are a collection of nodes and segments which are colour-coded yellow in the map pane. These segments are usually named to match the real-world route letters. You can leave the name blank for very small connectors and routes along the gate line. They can also be defined as one-way routes if planes always use them in only one direction.

To make a new taxi route, select the taxi routes tool and set the name and other properties in the toolbar, then click in the map pane to place the taxi route segments. The taxi route tool does not support bezier curves, so use short segments to approximate curves. If you cross an existing taxi route segment while creating a new one, WED will automatically insert a node at the intersection.

Taxi route segments cannot cross each other unless they are connected by a common node

The common node is essential because it ensures that there is a continuous path from any one route to any other route. This means that even if an airport has disjoint movement areas in the real world, the taxi routes in the application cannot be built that way. The entire grid of taxi routes must be connected.

To create a new taxi route in WED, you need to select the taxi routes tool and set the name and other properties in the toolbar. Then, you can click on the map pane to place the taxi route segments. It is important to note that the taxi route tool does not support bezier curves, so short segments should be used to approximate curves.

When creating a new taxi route, if you cross an existing taxi route segment, WED will automatically insert a node at the intersection. This helps to ensure that the taxi routes are properly connected and do not cross each other without a common node.

By following these guidelines, you can create functional taxi routes in WED that accurately represent the movement of aircraft around an airport.

The ENTIRE grid of taxi routes must be connected

When creating ATC taxi routes in WED, it is important to remember that the entire grid of taxi routes must be connected. This means that there should be a continuous path between all routes, and disjoint movement areas cannot exist, even if they are present in the real world.

To achieve this, taxi route segments, which are a collection of nodes and segments, are used to define each taxiway. These segments are typically drawn over the line markings that guide aircraft around the airport and are usually named to match the real-world route letters.

When creating a new taxi route, select the taxi routes tool and set the name and other properties in the toolbar, then click on the map pane to place the segments. WED will automatically insert a node at the intersection if you cross an existing taxi route segment.

It is also important to note that taxi route segments cannot cross each other unless they are connected by a common node. WED will prevent this from happening by placing a node where two crossing segments overlap.

By following these guidelines, you can ensure that your ATC taxi routes in WED are connected and function correctly.

Every runway that is used in ANY flow needs to have a taxi route on it

Taxi Route Authoring in WED

A taxi route is a collection of line segments. Each taxiway segment can be defined as departure/arrival hot zones. For the taxi route to function correctly, a few things must be true:

• Taxi route segments cannot cross each other unless connected by a common node. WED automatically prevents this by placing a node where two crossing taxi route segments overlap.
• The entire grid of taxi routes must be connected – there should be a continuous path from any one route to any other route. This means you cannot build an airport with disjoint movement areas, even if it exists in the real world.
• Every runway that is used in any flow needs to have a taxi route on it so aircraft can get to and from the runway.
• Segments are colour-coded when viewed in the ATC Taxi + Flow tab, to provide an immediate sense of the properties assigned to each segment.

Basic Taxi Route Segments

The most basic taxi route segment is for taxiway on the pavement surrounding an airport. These are typically drawn over the line markings that guide aircraft around the airport. They are a collection of nodes and segments which are colour-coded yellow in the map pane.

These segments are typically named to match the real-world route letters. You can leave the name blank for very small connectors and routes along the gate line. They can also be defined as one-way routes if planes always use them in only one direction.

To make a new taxi route, select the taxi routes tool and set the name and other properties in the toolbar, then click in the map pane to place the taxi route segments. The taxi route tool does not support bezier curves, so use short segments to approximate curves.

If you cross an existing taxi route segment while creating a new taxi route, WED will automatically insert a node at the intersection.

Runway Taxi Route Segments

A runway taxi route is defined by selecting the appropriate runway from the Runway drop-down menu. The Name, Departures, Arrivals, and ILS Precision Area fields will be set automatically by WED. Runway segments are normally colour-coded blue in the WED map pane, but may also be purple if portions of that runway are also hot zones for other runways.

For all runway taxi routes:

• Taxi route nodes must be inside of the runway’s bounds. Only a small overflow zone past the ends of the runways is allowed.
• Taxi routes must be parallel to and as close as possible to the runway’s centreline.
• The runway must be sufficiently covered by the taxi route. This includes displaced thresholds, but excludes blast pads.
• All runway taxi routes must be properly connected to the rest of the taxi route.
• The property “Size” of runway segments has no function at all in X-plane.

Hot Zones

Hot zones are a location on an airport with a potential risk of collision or runway incursion, and where heightened attention by pilots and drivers is necessary. Usually a segment of the taxiway closest to the runway, or where runways overlap, hot zones are colour-coded red or purple (when crossing or on a runway) in the map pane.

All taxi route segments inside the hold short lines of the real airport should be marked as hot zones. The presence of the hot zone will cause the AI aircraft to correctly hold short at those hold short lines.

If the real-world airport is missing a hold short line on one side of the runway, you still need to mark a hot zone approximately where the aircraft would have to stop in order to be out of the way of runway operations.

Runways need hot zones too. When two runways cross, each one needs to have a hot zone marked near the crossing point of the other runway. If there are real land-and-hold-short markings (LAHSO) lines on the runway, this is a good place to start the hot zone. The hot zones are used when a runway is inactive (and being used as a taxiway), and also to detect conflicts between a landed aircraft that is taxiing off the runway and crossing arrivals and departures.

ILS Critical Zones

An ILS critical zone is a designated area of an airport that all physical obstructions must remain clear of when one or more Instrument Landing Systems are in use, to protect against signal interference or attenuation that may lead to navigation errors, or accident. ILS critical zones are colour-coded orange in the WED map pane.

Taxi Route Segment Sizing

Each taxi route segment has a size letter, which restricts the use of that segment by aircraft larger than the specified size. The sizes depend on the aircraft’s wingspan in X-Plane and are identical to ICAO aircraft size classifications:

• B < 24m: King Air C90
• C < 36m: B737, A320, MD-80
• D < 52m: B767, A310, MD-10
• E < 65m: B777, B747, A340

Although this is useful to prevent oversized aircraft visibly hitting their wings on nearby scenery objects, care must be taken to not specify small sizes for no valid reason. The maximum size of aircraft that may taxi or be present at a given airport is limited by the largest size taxi route specified in any of the ramp starts at that airport, plus runway size restrictions. If there is no path from any ramp start to the active runway wide enough to accommodate that aircraft, the ATC system may come to a full halt.

Segments are colour-coded when viewed in the ATC Taxi + Flow tab

When creating ATC taxi routes, it is important to understand the different types of segments and their respective colour codes. Segments are colour-coded when viewed in the ATC Taxi + Flow tab to provide a clear indication of the properties assigned to each segment.

The most basic type of segment is the taxiway segment, which surrounds the airport. These are typically drawn over the line markings that guide aircraft around the airport and are colour-coded yellow in the map pane. These basic taxi route segments are usually named to match the real-world route letters. However, for very small connectors and routes along the gate line, the name can be left blank. Additionally, these segments can be defined as one-way routes if planes always use them in a single direction.

Another type of segment is the runway taxi route segment, which is associated with a specific runway. These segments are typically colour-coded blue in the map pane, but they may also appear purple if portions of the runway serve as hot zones for other runways. It is important to note that runway taxi route nodes must remain within the runway's bounds, with only a small overflow zone allowed beyond the runway ends.

Hot zones are critical areas on an airport where the risk of collision or runway incursion is elevated, requiring heightened attention from pilots and drivers. These zones are usually the segments of the taxiway closest to the runway or where runways overlap. In the map pane, hot zones are colour-coded red or purple, depending on their location. It is crucial to mark all taxi route segments within the hold short lines of the real airport as hot zones to ensure that AI aircraft correctly hold their position.

Furthermore, Instrument Landing System (ILS) critical zones are designated areas that must be kept clear of any physical obstructions when Instrument Landing Systems are in use. These zones are designed to protect against signal interference or attenuation that could lead to navigation errors or accidents. In the WED map pane, ILS critical zones are colour-coded orange for easy identification.

Each taxi route segment also has a size restriction, indicated by a letter, which limits the use of that segment by aircraft size. These size restrictions are based on the aircraft's wingspan and follow the ICAO aircraft size classifications.

Frequently asked questions