<?xml version="1.0" encoding="utf-8"?>
<!-- navaid.xsd version 0.4 - For more information on navaid and this
schema, visit http://http://navaid.com/GPX/ -->
<!-- This schema is intended as documentation for extending the GPX schema
and should not be used alone -->
<xsd:schema targetNamespace="http://navaid.com/GPX/NAVAID/0/4"
    xmlns:navaid="http://navaid.com/GPX/NAVAID/0/4"
    xmlns:xsd="http://www.w3.org/2001/XMLSchema"
    elementFormDefault="qualified">
<xsd:import namespace="http://www.topografix.com/GPX/1/1"
    schemaLocation="http://www.topografix.com/GPX/1/1/gpx.xsd"/>


<xsd:element name="frequencies" type="FrequenciesCollectionType"/>

<xsd:complexType name="FrequenciesCollectionType">
  <xsd:sequence>

    <!-- navaid frequency definition -->
    <xsd:element name="frequency" minOccurs="0" maxOccurs="unbounded">
        <xsd:complexType>
            <xsd:attribute name="type" type="xsd:string" use="required"/>
            <xsd:attribute name="frequency" type="xsd:string" use="required"/>
            <xsd:attribute name="name" type="xsd:string"/>
        </xsd:complexType>
    </xsd:element>
  </xsd:sequence>
</xsd:complexType>

<xsd:element name="runways" type="RunwaysCollectionType"/>

<xsd:complexType name="RunwaysCollectionType">
  <xsd:sequence>
    <!-- navaid runway definition -->
    <xsd:element name="runway" minOccurs="0" maxOccurs="unbounded">
        <xsd:complexType>
            <xsd:attribute name="designation" type="xsd:string" use="required"/>
            <xsd:attribute name="length" type="xsd:decimal" use="required"/>
            <xsd:attribute name="width" type="xsd:decimal" use="required"/>
            <xsd:attribute name="surface" type="xsd:string" use="required"/>
        </xsd:complexType>
    </xsd:element>

  </xsd:sequence>
</xsd:complexType>

<xsd:element name="tpa" type="xsd:decimal"/>

</xsd:schema>
