diff --git a/simgear/package/CMakeLists.txt b/simgear/package/CMakeLists.txt
index ae048978..6ed7ac9c 100644
--- a/simgear/package/CMakeLists.txt
+++ b/simgear/package/CMakeLists.txt
@@ -7,6 +7,7 @@ set(HEADERS
     Install.hxx
     Root.hxx
     Delegate.hxx
+    PackageCommon.hxx
     )
 
 set(SOURCES
diff --git a/simgear/package/Catalog.cxx b/simgear/package/Catalog.cxx
index 849b7f18..fb09685f 100644
--- a/simgear/package/Catalog.cxx
+++ b/simgear/package/Catalog.cxx
@@ -295,21 +295,27 @@ bool Catalog::removeDirectory()
     return d.remove(true /* recursive */);
 }
 
-PackageList const&
-Catalog::packages() const
+PackageList
+Catalog::packages(Type ty) const
 {
-  return m_packages;
+    PackageList r;
+    std::copy_if(m_packages.begin(), m_packages.end(),
+                 std::back_inserter(r),
+                 [ty](const PackageRef& p) {
+                     return p->type() == ty;
+                 });
+    return r;
 }
 
 PackageList
 Catalog::packagesMatching(const SGPropertyNode* aFilter) const
 {
     PackageList r;
-    for (auto p : m_packages) {
-        if (p->matches(aFilter)) {
-            r.push_back(p);
-        }
-    }
+    std::copy_if(m_packages.begin(), m_packages.end(),
+                 std::back_inserter(r),
+                 [aFilter](const PackageRef& p) {
+                     return p->matches(aFilter);
+                 });
     return r;
 }
 
@@ -317,27 +323,23 @@ PackageList
 Catalog::packagesNeedingUpdate() const
 {
     PackageList r;
-    for (auto p : m_packages) {
-        if (!p->isInstalled()) {
-            continue;
-        }
-
-        if (p->install()->hasUpdate()) {
-            r.push_back(p);
-        }
-    }
+    std::copy_if(m_packages.begin(), m_packages.end(),
+                 std::back_inserter(r),
+                 [](const PackageRef& p) {
+                     return p->isInstalled() && p->install()->hasUpdate();
+                 });
     return r;
 }
 
 PackageList
-Catalog::installedPackages() const
+Catalog::installedPackages(Type ty) const
 {
   PackageList r;
-  for (auto p : m_packages) {
-    if (p->isInstalled()) {
-      r.push_back(p);
-    }
-  }
+  std::copy_if(m_packages.begin(), m_packages.end(),
+               std::back_inserter(r),
+               [ty](const PackageRef& p) {
+                   return p->isInstalled() && p->type() == ty;
+               });
   return r;
 }
 
diff --git a/simgear/package/Catalog.hxx b/simgear/package/Catalog.hxx
index c83d5c45..5ca664e4 100644
--- a/simgear/package/Catalog.hxx
+++ b/simgear/package/Catalog.hxx
@@ -32,6 +32,7 @@
 #include <simgear/io/HTTPRequest.hxx>
 
 #include <simgear/package/Delegate.hxx>
+#include <simgear/package/PackageCommon.hxx>
 
 namespace simgear
 {
@@ -40,20 +41,6 @@ namespace HTTP { class Client; }
 
 namespace pkg
 {
-
-// forward decls
-class Package;
-class Catalog;
-class Root;
-class Install;
-
-typedef SGSharedPtr<Package> PackageRef;
-typedef SGSharedPtr<Catalog> CatalogRef;
-typedef SGSharedPtr<Install> InstallRef;
-
-typedef std::vector<PackageRef> PackageList;
-typedef std::vector<CatalogRef> CatalogList;
-
 class Catalog : public SGReferenced
 {
 public:
@@ -79,7 +66,7 @@ public:
     /**
      * Get all packages in this catalog.
      */
-    PackageList const& packages() const;
+    PackageList packages(Type ty = AircraftPackage) const;
 
     /**
      * retrieve packages in this catalog matching a filter.
@@ -90,7 +77,7 @@ public:
     /**
      * packages which are locally installed
      */
-    PackageList installedPackages() const;
+    PackageList installedPackages(Type ty = AircraftPackage) const;
 
     /**
      * retrieve all the packages in the catalog which are installed
diff --git a/simgear/package/Install.hxx b/simgear/package/Install.hxx
index 086c5284..c46de446 100644
--- a/simgear/package/Install.hxx
+++ b/simgear/package/Install.hxx
@@ -20,9 +20,10 @@
 
 #include <vector>
 
-#include <simgear/misc/sg_path.hxx>
 #include <simgear/misc/sg_dir.hxx>
+#include <simgear/misc/sg_path.hxx>
 #include <simgear/package/Delegate.hxx>
+#include <simgear/package/PackageCommon.hxx>
 
 #include <simgear/structure/function_list.hxx>
 #include <simgear/structure/SGReferenced.hxx>
@@ -35,15 +36,6 @@ namespace simgear
 namespace pkg
 {
 
-// forward decls
-class Package;
-class Catalog;
-class Install;
-  
-typedef SGSharedPtr<Package> PackageRef;
-typedef SGSharedPtr<Catalog> CatalogRef;  
-typedef SGSharedPtr<Install> InstallRef;
-  
 /**
  *
  */
diff --git a/simgear/package/Package.cxx b/simgear/package/Package.cxx
index 7feafe53..cb9e34fe 100644
--- a/simgear/package/Package.cxx
+++ b/simgear/package/Package.cxx
@@ -29,10 +29,30 @@
 #include <simgear/package/Install.hxx>
 #include <simgear/package/Root.hxx>
 
+namespace {
+
+const string_list static_typeNames = {
+    "aircraft",
+    "ai-model",
+    "add-on"};
+
+}
+
 namespace simgear {
 
 namespace pkg {
 
+Type typeFromString(const std::string& s)
+{
+    const auto l = strutils::lowercase(s);
+    const auto it = std::find(static_typeNames.begin(), static_typeNames.end(), l);
+    if (it != static_typeNames.end()) {
+        return static_cast<Type>(std::distance(static_typeNames.begin(), it));
+    }
+
+    return AircraftPackage; // for backwards-compat
+}
+
 Package::Package(const SGPropertyNode* aProps, CatalogRef aCatalog) :
     m_catalog(aCatalog.get())
 {
@@ -53,6 +73,12 @@ void Package::initWithProps(const SGPropertyNode* aProps)
     for (auto var : m_props->getChildren("variant")) {
         m_variants.push_back(var->getStringValue("id"));
     }
+
+    if (aProps->hasChild("type")) {
+        m_type = typeFromString(m_props->getStringValue("type"));
+    } else {
+        m_type = AircraftPackage;
+    }
 }
 
 void Package::updateFromProps(const SGPropertyNode* aProps)
@@ -133,6 +159,12 @@ bool Package::matches(const SGPropertyNode* aFilter) const
         }
     }
 
+    if (filter_name == "type") {
+        handled = true;
+        const auto n = strutils::lowercase(aFilter->getStringValue());
+        return (n == static_typeNames.at(static_cast<int>(m_type)));
+    }
+
     if (!handled) {
       SG_LOG(SG_GENERAL, SG_WARN, "unknown filter term:" << filter_name);
     }
@@ -186,10 +218,23 @@ bool Package::isInstalled() const
     return pathOnDisk().exists();
 }
 
+std::string Package::directoryForType(Type type)
+{
+    switch (type) {
+    case AircraftPackage:
+    default:
+        return "Aircraft";
+    case AIModelPackage:
+        return "AI/Aircraft";
+    case AddOnPackage:
+        return "Add-On";
+    }
+}
+
 SGPath Package::pathOnDisk() const
 {
     SGPath p(m_catalog->installRoot());
-    p.append("Aircraft");
+    p.append(directoryForType(m_type));
     p.append(dirName());
     return p;
 }
@@ -585,6 +630,10 @@ bool Package::validate() const
     return true;
 }
 
+Type Package::type() const
+{
+    return m_type;
+}
 
 } // of namespace pkg
 
diff --git a/simgear/package/Package.hxx b/simgear/package/Package.hxx
index 88408c54..abb850bd 100644
--- a/simgear/package/Package.hxx
+++ b/simgear/package/Package.hxx
@@ -28,6 +28,8 @@
 #include <simgear/structure/SGReferenced.hxx>
 #include <simgear/structure/SGSharedPtr.hxx>
 
+#include <simgear/package/PackageCommon.hxx>
+
 typedef std::set<std::string> string_set;
 
 namespace simgear
@@ -35,19 +37,7 @@ namespace simgear
 
 namespace pkg
 {
-
-// forward decls
-class Install;
-class Catalog;
-class Package;
-
-typedef SGSharedPtr<Package> PackageRef;
-typedef SGSharedPtr<Catalog> CatalogRef;
-typedef SGSharedPtr<Install> InstallRef;
-
-typedef std::vector<PackageRef> PackageList;
-
-  class Package : public SGReferenced
+class Package : public SGReferenced
 {
 public:
 
@@ -214,6 +204,11 @@ public:
      * (parents and children)
      */
     std::string parentIdForVariant(unsigned int variantIndex) const;
+
+    Type type() const;
+
+    static std::string directoryForType(Type type);
+
 private:
     SGPath pathOnDisk() const;
 
@@ -240,6 +235,7 @@ private:
     bool matchesDescription(const std::string &search) const;
     
     SGPropertyNode_ptr m_props;
+    Type m_type;
     std::string m_id;
     string_set m_tags;
     Catalog* m_catalog = nullptr; // non-owning ref, explicitly
diff --git a/simgear/package/PackageCommon.hxx b/simgear/package/PackageCommon.hxx
new file mode 100644
index 00000000..1902e6ab
--- /dev/null
+++ b/simgear/package/PackageCommon.hxx
@@ -0,0 +1,52 @@
+// Copyright (C) 2021 James Turner - james@flightgear.org
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Library General Public
+// License as published by the Free Software Foundation; either
+// version 2 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Library General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+//
+
+#pragma once
+
+#include <vector>
+
+#include <simgear/structure/SGSharedPtr.hxx>
+
+namespace simgear {
+
+namespace pkg {
+
+enum Type {
+    AircraftPackage = 0,
+    AIModelPackage,
+    AddOnPackage
+
+    // if you extend this enum, extend the static_typeNames string array
+    // in Package.cxx file as well.
+};
+
+// forward decls
+class Install;
+class Catalog;
+class Package;
+class Root;
+
+typedef SGSharedPtr<Package> PackageRef;
+typedef SGSharedPtr<Catalog> CatalogRef;
+typedef SGSharedPtr<Install> InstallRef;
+
+typedef std::vector<PackageRef> PackageList;
+typedef std::vector<CatalogRef> CatalogList;
+
+} // namespace pkg
+
+} // namespace simgear
diff --git a/simgear/package/Root.cxx b/simgear/package/Root.cxx
index 983729fb..affac887 100755
--- a/simgear/package/Root.cxx
+++ b/simgear/package/Root.cxx
@@ -534,13 +534,13 @@ CatalogList Root::allCatalogs() const
 }
 
 PackageList
-Root::allPackages() const
+Root::allPackages(Type ty) const
 {
     PackageList r;
 
     CatalogDict::const_iterator it = d->catalogs.begin();
     for (; it != d->catalogs.end(); ++it) {
-        const PackageList& r2(it->second->packages());
+        const PackageList& r2(it->second->packages(ty));
         r.insert(r.end(), r2.begin(), r2.end());
     }
 
diff --git a/simgear/package/Root.hxx b/simgear/package/Root.hxx
index a1114461..05adbddf 100644
--- a/simgear/package/Root.hxx
+++ b/simgear/package/Root.hxx
@@ -23,6 +23,7 @@
 
 #include <simgear/misc/sg_path.hxx>
 #include <simgear/package/Delegate.hxx>
+#include <simgear/package/PackageCommon.hxx>
 
 #include <simgear/structure/SGReferenced.hxx>
 #include <simgear/structure/SGSharedPtr.hxx>
@@ -40,18 +41,6 @@ namespace HTTP {
 namespace pkg
 {
 
-// forward decls
-class Package;
-class Catalog;
-class Install;
-  
-typedef SGSharedPtr<Package> PackageRef;
-typedef SGSharedPtr<Catalog> CatalogRef;
-typedef SGSharedPtr<Install> InstallRef;
-  
-typedef std::vector<PackageRef> PackageList;
-typedef std::vector<CatalogRef> CatalogList;
-
 class Root : public SGReferenced
 {
 public:
@@ -114,8 +103,8 @@ public:
     /**
      *
      */
-    PackageList allPackages() const;
-    
+    PackageList allPackages(Type ty = AircraftPackage) const;
+
     /**
      * retrieve packages matching a filter.
      * filter consists of required / minimum values, AND-ed together.